Tesi: "Bovine serum albumin"

1

Marincic, Patricia Z. "Quantitation of Bovine Serum Albumin in Cow's-Milk-Based Infant Formulas and Removal of Bovine Serum Albumin from Cow's Milk and Whey Protein Isolates". DigitalCommons@USU, 1997. https://digitalcommons.usu.edu/etd/5443.

Testo completo

Abstract (sommario):

Early introduction of cow's-milk-based infant formulas, in particular the ABBOS epitope of bovine serum albumin (BSA), has been implicated as an autoimmune trigger in the pathogenesis of insulin dependent diabetes mellitus (IDDM). A direct enzyme-linked immunosorbant assay (ELISA), using polyclonal anti-BSA antibodies, was developed to determine the BSA content of cow's milk and 15 infant formulas. Powdered high-whey (60%) formulas averaged 41 mg BSA/100 ml; 2% milk contained 52 mg BSA/100 ml; and the high-casein formulas averaged 13 mg/100 ml. BSA content of powdered polymeric formulas and cow's milk varied directly with the whey protein concentration (correlation coefficient = 0.8445, Q = 0.008). BSA was not detected in any hydrolyzed powdered formula or commercially sterile liquid preparation regardless of protein composition. The absence of BSA was confirmed by polyacrylamide gel electrophoresis. It is unlikely that the ABBOS epitope is present in the formulas testing negative for BSA due to enzymatic hydrolysis and heat denaturation of these formula preparations. A laboratory technology was developed that could be upgraded to produce BSA free protein bases used in the manufacture of infant formula. Affinity chromatography, using paramagnetic beads with an immobilized antibody against BSA, was applied to extract BSA from cow's milk and whey isolates. Monoclonal and polyclonal antibody-activated beads were used to capture BSA from samples. The capture efficiency in milk was 11% and 19% for polyclonal beads, and 59% for monoclonal beads. Capture efficiency of monoclonal beads of 91% was significantly greater in both acid and sweet whey compared to the polyclonal beads exhibiting a capture efficiency 31% and 24% in acid and sweet whey, respectively. Capture efficiency of monoclonal and polyclonal beads did not differ significantly in milk, acid whey, or sweet whey. Removal of BSA from a known sample of 25ng of BSA treated with polyclonal beads was 70% effective with a capture efficiency of 35%. A net reduction of 99.9% of the BSA could be expected by coupling immunocapture with molecular sieving. Immunocapture was most effective in removing BSA when only small amounts were present in the sample.

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Pfeilsticker, Neves Renata. "Glycated Bovine Serum Albumin for Curcumin Nanoencapsulation: Bio-Nano Interactions". Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42583.

Testo completo

Abstract (sommario):

Glycation of whey proteins results in food-grade composites with modified physicochemical properties. Here, the reaction between glucose and bovine serum albumin (BSA) is promoted under wet-heating conditions. The glycated protein is characterized in depth and compared to the native counterpart and the impact of glycation on properties like net surface charge, particle size and surface hydrophobicity are observed. Conjugation with glucose reduced the surface hydrophobicity of BSA but the interactions between albumin and curcumin became stronger, which contradicts the direct relationship between curcumin binding affinity and protein surface hydrophobicity described in the literature. Nonetheless, curcumin was still capable of quenching the intrinsic fluorescence of the protein after conjugation with glucose and leads to the conclusion that curcumin and BSA interact in a different manner upon glycation. This thesis also depicts mucin as a forthcoming model in the study of nanoparticle interactions with intestinal mucus and glycation posed no effect on such interactions.

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Castro, Ana Carolina Santos de. "Measurement of anti-bovine serum albumin antibodies in dogs with chronic enteropathy". Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2019. http://hdl.handle.net/10400.5/18986.

Testo completo

Abstract (sommario):

Dissertação de Mestrado Integrado em Medicina Veterinária
Chronic Enteropathy (CE) is a complex disease that is thought to result from an overstated immune response against alimentary and microbiota antigens in susceptible animals. The amplified inflammation of the mucosa promoted by the increased and abnormal gut permeability in sick patients known as ‘leaky gut’, allows the antigens to pass through the systemic circulation, culminating in an unbalanced excessive immune response that is followed by the production of specific Immunoglobulins (Ig). Bovine protein is historically believed to be one of the highest immune triggers in dogs with CE. However, studies about the use of anti-bovine serum albumin antibodies (anti-BSAA) as potential biomarkers of a disrupted immune-response in dogs with CE are lacking. This study aimed to compare anti-BSA antibody values (IgA/IgG) between healthy dogs and dogs diagnosed with CE, assessing its potential utility as a biomarker of a leaky gut. A case-control study was conducted including a total of 21 dogs, divided into two distinct groups. The first group consisted on 8 client-owned healthy adult dogs (control group), fed with current adult standard dry diet; the second group was composed by 13 client-owned dogs with clinical signs of CE that historically contacted with standard diets of bovine-protein but were latter fed with an hydrolyzed bovine-free diet for at least two weeks. Serum samples were obtained and anti-BSA Antibodies (IgA/IgG) measured, using a species-specific ELISA kit. There was no significant difference on IgA levels between groups (p= 0,119). Concerning IgG, serial titers were lower in diseased dogs, when compared to the control group (P=0.046). Anti-BSAA do not seem to be good biomarkers of “leaky gut”. A possible explanation for the fact that IgG levels are higher in healthy dogs relies on the diet protein source, which can contain bovine extracts. Assuming that diseased dogs had previously contacted with bovine-proteins, other possibility is that dogs with chronic enteropathy are not able to produce enough immune-globulins, showing a poor humoral immunity towards bovine antigens. Accordingly to previous studies, these results also disbelieves the use of serologic serum profiles to assess potential dietary antigenicity. Albeit bovine protein is historically believed to be one of the highest immune triggers in dogs with CE, these preliminary results supports that anti-BSAA do not seem to be good biomarkers of a “leaky gut”. Further studies are needed to evaluate if low-IgG levels can be related with a poor humoral immune response in dogs with CE.
RESUMO - DETECÇÃO E DOSEAMENTO DE ANTICORPOS SÉRICOS ANTI-ALBUMINA BOVINA EM CÃES COM ENTEROPATIA CRÓNICA - A Enteropatia crónica (EC) é uma doença complexa e multifatorial que se acredita ser resultado de uma resposta imunitária exacerbada a antigénios alimentares e/ou microbianos em animais geneticamente suscetíveis. A inflamação da mucosa intestinal é resultante de uma permeabilidade aumentada da barreira intestinal, o que permite a passagem de antigénios do lúmen para a circulação sistémica. Esta alteração culmina numa resposta imunitária exacerbada com consequente produção inapropriada de imunoglobulinas especificas. A proteína bovina é atualmente aceite como um dos principais desencadeadores imunitários em cães com EC. O presente estudo visa comparar os valores de anticorpos específicos anti-BSA (IgA/IgG) em cães saudáveis e em cães diagnosticados com EC, estimando a potencial utilidade destes como biomarcador de alteração de permeabilidade intestinal (“leaky gut”). Foi efetuado um estudo do tipo caso-controlo que incluiu um total de 21 cães. Estes foram divididos em 2 grupos: grupo controlo (constituído por 8 cães adultos clinicamente saudáveis e alimentados com ração standard para adultos) e um grupo composto por 13 cães com sinais clínicos de EC. Em ambos os grupos foram medidos os anticorpos anti-BSA, através das amostras de soro obtidas e recorrendo a um kit ELISA espécie-específico. Relativamente aos níveis séricos de IgA, não houve diferença significativa entre os dois grupos (p=0,119). No entanto, os níveis de IgG foram significativamente inferiores em cães com EC, quando comparados ao grupo de controlo (p=0,046). O decréscimo observado em cães com EC pode ser explicado por uma eventual produção insuficiente de imunoglobulinas, consequente de uma fraca resposta humoral em relação aos antigénios bovinos. Outra possível explicação para o facto de os níveis de IgG serem mais elevados em cães saudáveis pode residir na origem da proteína animal da dieta, que poderá conter extratos bovinos. Embora se defenda que a proteína bovina seja um dos maiores estímulos imunitários em cães com EC, estes resultados sustentam que os anticorpos anti-BSA não aparentam ser biomarcadores adequados a esta condição. Este trabalho corrobora estudos anteriores que questionam o uso de perfis séricos sorológicos para avaliar a potencial antigenicidade alimentar. São necessários mais estudos para esclarecer se baixos títulos de IgG poderão estar relacionados com uma deficiente resposta imune humoral em cães com CE.
N/A

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Yeung, Kai Ming. "The adsorption of bovine serum albumin on fused silica : a single molecules study". HKBU Institutional Repository, 2008. http://repository.hkbu.edu.hk/etd_ra/1017.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Alansari, Wafa S. "Antioxidant and angiotensin converting enzyme inhibitory activities from bovine serum albumin". Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/810091/.

Testo completo

Abstract (sommario):

Bioactive peptides represent an important source of health promoting food. Therefore, the objective of this study was to identify the in vitro antioxidant and ACE inhibitory peptides derived from bovine serum albumin (BSA) and to characterise them after further purification. To achieve this objective, BSA was hydrolyzed with pepsin enzyme, fractionated by ultrafiltration using a 10 kDa molecular weight cut off membrane, and purified by gel filtration chromatography prior to characterisation. The total antioxidant activity was evaluated in a linoleic acid model system using the ferric thiocyanate (FTC) and thiobarbituric acid reactive species (TBARS) methods. The results indicated that gel filtration fraction number 18 exhibited the highest FTC antioxidant activity (65.4 %) compared to the (< 10 kDa) ultrafiltration fraction (44.8 %) and BSA hydrolysate (34.9 %) using a concentration of 1mg peptide/ml. However, the peptide activities were lower than those of 0.01 % butylated hydroxyanisole (69.9 %) and 0.01 % trolox (78.5 %) (P ≤ 0.05). Likewise, TBARS inhibition values were 42.8, 54.8, 76.7 and 84.4 % for BSA hydrolysate, < 10 kDa, BHA and trolox, respectively. The antioxidant activity of the (Mw < 10 kDa) peptide was demonstrated by strong free radical scavenging using the 1, 1-diphenyl-2-picrylhydrazyl (DPPH•), hydroxyl (OH•) and superoxide anion (O2-•); ferric (Fe3+) reducing and ferrous (Fe2+) metal ion chelating capacity and reducing power activity. A second gel filtration fraction number 22 exhibited the highest ACE inhibitory activity (79.5%) compared to the (10 kDa) ultrafiltration fraction (44.7%) and BSA hydrolysate (33.2 %) at a concentration of 10 mg/ml, with corresponding low IC50 values of 0.32, 0.56 and 0.75 mg/ml respectively compared to captopril (88.5%, P ≤ 0.05). The peptide (GF 18) at 1 mg/ml had no cytotoxic effect in epithelial caco-2 cells. Moreover, the presence of the peptide showed high cell viability (99.7%) and reduced malondialdehyde formation (27.7 µg/ml) compared with cells treated with 3mM t-BHP alone, which showed low cell viability (54.6%) and high MDA (30.3 µg/ml) (P < 0.01). BSA peptides protected t-BHP treated cells from caspase-dependent apoptosis; inhibited intracellular ROS production and increased glutathione level and SOD activity. Similarly, the GF 22 peptides (1 mg/ml) protected the endothelial EA.hy 926 against 3mM t-BHP damage and showed reduced mROS production by both lucigenin-enhanced chemiluminescence and the DHE fluorescence techniques. Additionally, the peptides reduced nitrite concentration and inhibited the activity of angiotensin converting enzyme in a dose dependent manner. This study reports novel findings showing that BSA peptides have antioxidant and ACE inhibitory activities that could potentially be used as food supplements and pharmaceutical agents.

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Puckett, Nathan. "Effects of Binding Affinity between Bovine Serum Albumin and Platinum Drugs". TopSCHOLAR®, 2017. http://digitalcommons.wku.edu/theses/1977.

Testo completo

Abstract (sommario):

Platinum complex drugs such as cisplatin have been used as highly successful chemotherapy drugs since the 1970s. We are interested in how the ligands attached to cisplatin analogs influences their reactivity with biologically relevant targets along with time and amount. For this study, reactions were conducted to determine the reactivity between different platinum compounds and the protein bovine serum albumin. Various platinum compounds with different ligands were reacted in varying amounts with albumin in ammonium acetate buffer for either 1 hour, 4 hours, or 24 hours. Each reaction was quenched after the designated reaction time by dialysis and the platinum bound to the protein was determined by use of ICP. LC-MS was used to find exact peptide residues platinum complexes prefer to bind with but was found to be ineffective. Results show that time has a more significant affect on binding over amount of platinum present. In respect to changing the leaving or carrier ligands on the platinum complex, these changes on the complex did not affect binding significantly with bovine serum albumin. Triamine platinum complexes also seem to bind significantly more than diamine platinum complexes along with anionic form platinum complexes binding significantly better than the cationic form platinum complexes.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Lai, Chun-Chih. "Bovine serum albumin adhesion force measurements using an atomic force microscopy". Thesis, Queensland University of Technology, 2006. https://eprints.qut.edu.au/16418/1/Chun-Chih_Lai_Thesis.pdf.

Testo completo

Abstract (sommario):

In this thesis, a direct method of Atomic Force Microscopy (AFM) technique has been developed to measure the adhesion forces between BSA and two different surfaces: mica (a hydrophilic surface); and polystyrene (a hydrophobic surface); in PBS solution. We have shown possible to measure interactions between proteins and substrate surface directly without any modification to the substrate and the AFM tip; this means protein molecules can keep the natural elastic property within the force measurements. The average measured value of adhesion forces between BSA and mica is 0.036 ± 0.002 nN, and between BSA and polystyrene is 0.066 ± 0.003 nN. The polystyrene surface is more adhesive to BSA than the mica surface. This is consistent with previous research, which assessed that hydrophobic surfaces enhance protein adhesion but hydrophilic surfaces do not.

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Lai, Chun-Chih. "Bovine serum albumin adhesion force measurements using an atomic force microscopy". Queensland University of Technology, 2006. http://eprints.qut.edu.au/16418/.

Testo completo

Abstract (sommario):

In this thesis, a direct method of Atomic Force Microscopy (AFM) technique has been developed to measure the adhesion forces between BSA and two different surfaces: mica (a hydrophilic surface); and polystyrene (a hydrophobic surface); in PBS solution. We have shown possible to measure interactions between proteins and substrate surface directly without any modification to the substrate and the AFM tip; this means protein molecules can keep the natural elastic property within the force measurements. The average measured value of adhesion forces between BSA and mica is 0.036 ± 0.002 nN, and between BSA and polystyrene is 0.066 ± 0.003 nN. The polystyrene surface is more adhesive to BSA than the mica surface. This is consistent with previous research, which assessed that hydrophobic surfaces enhance protein adhesion but hydrophilic surfaces do not.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Needham, Judy. "Adsorption of bovine serum albumin to polyethylene tubing reversibility and pH-dependence". Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28293.

Testo completo

Abstract (sommario):

This thesis is concerned with the adsorption of bovine serum albumin to polyethylene tubing. A method using radioiodinated protein was developed to measure the surface concentration taking into account the dilution effect for miscible displacement in a capillary. A steady-state surface concentration was established within 2 hours. Adsorption did not depend on the ratio of radiolabelled to unlabel led protein. The adsorption isotherm was Langmuir-like with a plateau concentration of approximately 0.2 μg/cm². Two methods were used to calculate the surface concentration in the desorption study. The surface concentration calculated by depletion of the total radioactivity was always higher than that calculated from assaying the radioactivity associated with the tubing. Desorption of at least 5% of the loosely bound protein occurs. The surface concentration-pH data show two maxima. The first is at the isoelectric point of the albumin while the second is at pH 9.5-10. The second maximum seems to be due to preferential adsorption of the higher molecular weight oligomers in the protein sample.
Science, Faculty of
Chemistry, Department of
Graduate

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Franco, Luís Fernando Mercier. "Study on the thermodynamics of bovine serum albumin aqueous solutions: experiments, modeling and molecular simulations". Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-14072016-140814/.

Testo completo

Abstract (sommario):

The interaction between two proteins into salt aqueous solutions is investigated throughout this thesis. Experiments, modeling and molecular simulations were carried out to get a better understanding of the phenomenon. Bovine serum albumin was used as a model protein. An analytical expression for the structure factor for globular proteins in aqueous solution is presented in this work. This expression was obtained considering an intermolecular potential given by the sum of a hard core, a van der Waals attractive and a screened Coulomb contribution. Experimental data of Small Angle X-Ray Scattering for bovine serum albumin in aqueous solutions containing sodium salts at different protein concentrations and pH values are also presented. The expression developed for the structure factor describes accurately these experimental data provided a dependence of the attractive parameter on protein concentration is established. An expression for the osmotic pressure was derived from the structure factor. With attractive parameters adjusted from X-ray scattering data, the osmotic pressure of bovine serum albumin aqueous solutions could be predicted with very good agreement with experimental data. A derivation of the thermodynamic potentials, such as the chemical potential, using the new osmotic equation of state is presented. Applying the phase equilibrium criterion, the fluid-fluid phase equilibrium for bovine serum albumin in salt aqueous solution was calculated. Although such separation was not experimentally observed at the isoelectric point, it was indeed experimentally observed for a pH value below the isoelectric point. The predictions seem to be valuable to discuss how ion specificity affects the phase diagram of proteins. To apply molecular dynamic techniques to simulate how proteins interact to each other in salt aqueous solutions, two new coarse-grained force fields are proposed. The first one, meant for sodium sulfate aqueous solution, avoids the unphysical association observed for non-polarizable atomistic force fields; and allows the prediction of thermodynamic and dynamic properties. The second one, meant for bovine serum albumin in aqueous solution, is used as a new strategy to evaluate the scattering form factor of proteins as a low resolution technique for protein structure prediction.
Nesta tese apresenta-se uma investigação sobre a interação entre duas proteínas em soluções aquosas salinas. Experimentos, modelagem e simulações moleculares foram realizadas para conseguir um melhor entendimento do fenômeno. Albumina de soro bovina foi usada como proteína modelo. Uma expressão para o fator de estrutura de proteínas globulares em solução aquosa é apresentada neste trabalho. Esta expressão foi obtida considerando-se um potencial intermolecular dado pela soma de um núcleo duro, uma contribuição atrativa tipo vander Waals e uma contribuição de potencial coulômbico blindado. Dados experimentais de espalhamento de raios-X a baixos ângulos para a albumina de soro bovino em soluções aquosas contendo sais de sódio com diferentes concentrações de proteína e valores de pH também são apresentados. A expressão desenvolvida para o fator de estrutura descreve com precisão estes dados experimentais, desde que uma dependência entre o parâmetro atrativo com a concentração de proteína seja estabelecida. Uma expressão para a pressão osmótica foi derivada do fator de estrutura. Com parâmetros atrativos ajustados aos dados de espalhamento de raios-X, a pressão osmótica da albumina de soro bovino em solução aquosa pôde ser predita com grande correlação com os dados experimentais. Uma derivação dos potenciais termodinâmicos usando a nova equação osmótica de estado é apresentada. Aplicando o critério de equilíbrio de fases, foi possível calcular o equilíbrio fluido-fluido para a albumina de soro bovino em solução aquosa. Embora tal separação não tenha sido observada experimentalmente em um pH igual ao ponto isoelétrico, ela foi de fato observada experimentalmente para um valor de pH menor do que o ponto isoelétrico. As predições parecem ser valiosas para discutir como a especificidade iônica afeta o diagrama de fases de proteínas. De modo a avaliar como proteínas interagem umas com as outras usando técnicas de dinâmica molecular, dois novos campos de força coarse-grained são propostos. O primeiro, para o sulfato de sódio em solução aquosa, evita a associação não-física que é observada para campos de força atomísticos não-polarizáveis. Este modelo é capaz de prever propriedades dinâmicas e termodinâmicas. O segundo, para a albumina de soro bovino em solução aquosa, é usado como uma nova estratégia para avaliar o fator de forma de espalhamento de proteínas como uma ferramenta de baixa resolução na predição de estruturas proteicas.

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Zhang, Dawei. "Fabrication of bovine serum albumin nanotubes through template assisted layer by layer assembly". Worcester, Mass. : Worcester Polytechnic Institute, 2009. http://www.wpi.edu/Pubs/ETD/Available/etd-050609-135441/.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Pyshnov, Elizabeth. "Electrochemical studies of the adsorption of bovine serum albumin on a platinum surface". Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81558.

Testo completo

Abstract (sommario):

This thesis reports results on the investigation of the thermodynamics and kinetics of adsorption of bovine serum albumin (BSA) on a platinum electrode at pH 7.4 in a wide temperature range using the electrochemical techniques of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential capacitance (DC).
The adsorption of BSA at anodic potentials has been found to be a competitive process occurring in parallel with platinum oxide formation. It has been found that the adsorption charge is directly proportional to the amount of protein adsorbed. With the increase in temperature, the maximum amount of adsorbed BSA (saturated surface concentration) also increases. This dependence has been found to be linear. It has also been shown that the adsorption process is dependent on the electrode surface charge.

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Murphy, Margaret Clare. "The elucidation of structure-function relationships in bovine serum albumin by chemical modification". Thesis, University of Surrey, 1989. http://epubs.surrey.ac.uk/844202/.

Testo completo

Abstract (sommario):

The potential of using chemical modification as a tool to determine structure-function relationships was examined using one standard protein namely bovine serum albumin. The chemical modifications investigated included succinylation with succinic anhydride; thiolation, using N-acetyl homocysteine thiolactone; guanidination with O-methylisourea; the addition of cysteine hydrochloride; attachment of valine using an N-carboxyl anhydride derivative and of butylamine, putrescine and lysine via carbodiimide mediated condensation reactions. The native and modified proteins were subjected to a set of standard tests including assessment of amino, sulphydryl and hydrophobic groups and changes in the pH titration curve, amino acid composition, electrophoretic patterns and circular dichroism spectra. The functional properties examined included gelling, whipping and emulsification. The blocking of amino groups by succinylation and thiolation resulted in reduced functional properties whereas the addition of the hydrophobic amino acid valine resulted in improved functional properties. Improved whipping resulted when succinylated BSA was inadequately purified and in the presence of calcium the gelling strength of succinylated protein was significantly increased compared to the native BSA. In addition, ultrafiltration decreased the gelling properties of BSA. Cysteine modified samples showed little change in physicochemical or functional properties. A limited modification by guanidination or by carbodiimide condensation showed improved functional properties whereas an extensive modification resulted in poor functional properties. This was thought to be due to detrimental conformational changes in the extensively modified samples. A positive interaction between modified samples was shown to be dependent on the availability of amino groups and not the difference in charge as was expected. All modified samples showed little improvement in emulsification properties. In conclusion, the analysis of chemical modifications in the evaluation of certain structure-function relationships proved useful, but in order to elucidate the precise mechanisms involved, the information obtained from other methods of evaluation will be required.

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Barreau, Stephanie. "Biosensing with sol-gel-immobilised proteins". Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/27275.

Testo completo

Abstract (sommario):

Low temperature-processed, porous sol-gel glasses represent a new class of materials for the immobilisation of biomolecules. If used to entrap biological recognition elements, these transparent and chemically inert glasses offer a new approach in the development of optical biosensors.

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Hirzallah, Rana Rasim W. "Corrosion behavior of Co28Cr6Mo implant in the presence of bovine serum albumin and hyaluronic acid". Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/51349.

Testo completo

Abstract (sommario):

CoCrMo is one of the most widely used materials for prostheses. CoCrMo has high wear resistance, excellent corrosion resistance, and good biocompatibility. High corrosion resistance is ascribed to the formation of an oxide layer. However, the oxide layer does not remain intact in the corrosive body environment that contains oxygen, chloride, proteins, and carbohydrates. The presence of organic and inorganic species changes the oxide layer of CoCrMo to facilitate corrosion. Corrosion is one of the main issues that leads to revision surgery. CoCrMo has been used extensively in synovial joints replacements such as hip, knee, and shoulder. They are in contact with synovial fluid (SF) which mainly contains albumin and hyaluronic acid (HA). The concentrations of HA changes with age, sex, and diseases. The objective of this study is to investigate the effect of the main constituents of SF which are bovine serum albumin (BSA) and HA, on the corrosion performance of CoCrMo. In addition, this study also investigates the effect of changing HA concentrations on the corrosion behavior of CoCrMo. Increasing HA concentrations has reduced the pain for people with osteoarthritis. It may also have an effect on reducing the corrosion rate. To study the corrosion behavior of CoCrMo, different electrochemical techniques has been used to understand the formation and breakdown of the oxide layer, and calculate the corrosion rate by measuring the corrosion resistances and corrosion current densities. The results of electrochemical impedance spectroscopy (EIS) show that 4 gL-¹ of hyaluronic acid (HA) with bovine serum albumin (BSA) exhibited the highest corrosion resistance and the lowest corrosion rate of CoCrMo compared to only phosphate buffer saline (PBS), BSA, and PBS with different HA concentration.
Applied Science, Faculty of
Materials Engineering, Department of
Graduate

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Laffey, Brian David. "Monoclonal antibodies to bovine serum albumin : affinity purification and physicochemical characterization dc by Brian David Laffey". Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/32640.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Givens, Brittany Estelle. "The bovine serum albumin protein corona on nanoparticles: investigating the effects of changing pH, substrates, and ions". Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5479.

Testo completo

Abstract (sommario):

Nanoparticles are currently used in a wide range of applications including industrially processes, consumer products, and as drug delivery vehicles. The potential toxicity of these nanoparticles in living organisms is concerning due to their ever-expanding applications and accumulation in the environment. The effects of properties of the human body on the potential harmful nature of these nanoparticles must be understood in order to ensure safety in workplaces and at-home products. In this thesis, the interactions between nanoparticles and the most abundant blood protein, serum albumin, were investigated. The effects of changing the aqueous environment was investigated over a range of different pH values and with different ionic salts dissolved in water. The effects of changing the nanoparticle substrate were investigated to determine if different nanoparticles affect proteins differently. Finally, the effects of changing the concentration of nanoparticles and the presence of protein were investigated in a model lung cell line in vitro. The studies over different pH values revealed that serum albumin was able to adsorb to the silica nanoparticle surface, and retained its secondary structure both as a function of pH and adsorption in a 2-hour time frame. However, adsorption was greater on the titanium dioxide nanoparticle surface and the protein lost secondary structure at acidic pH (pH 2.0). Studies with different ionic salts revealed a possible correlation between BSA adsorption and nanoparticle aggregation in that the attractive interactions between nanoparticles were least when the least amount of protein was adsorbed. To the nanoparticle surface. In vitro studies with A549 human adenocarcinoma lung cells were inconclusive in determining the potential toxicity of these nanoparticles, but preliminary results suggested that the addition of protein to the system decreased toxicity compared with nanoparticles alone. This research aims to inform the field of nanotechnology to investigate the safety and efficacy of nanoparticles before they reach the consumer.

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Stinson, Jelynn A. "Applications of Capillary Electrophoresis for Studying Serum Albumin Enantioselection of D,L-Tryptophan Analogs". Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1346894633.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Windvoel, Victoria Thobile. "Effects of selected emulsion components; (bovine serum albumin, lipase and glutaraldehyde), on the surface properties of Polydimethylsiloxane". Thesis, University of Limpopo (Medunsa Campus), 2011. http://hdl.handle.net/10386/437.

Testo completo

Abstract (sommario):

Thesis (MSc (Biochemistry))--University of Limpopo, 2011.
The purpose of this study was to investigate the effects of bovine serum albumin (BSA), lipase and glutaraldehyde on the surface of polydimethylsiloxane (PDMS). PDMS blocks of 15 by 15mm were fabricated using replica micromolding. To determine the effects of BSA, clean PDMS blocks were immersed in 20, 50 and 100mg/ml BSA, respectively. For the effect of lipase, the concentration was 20, 50 and 70mg/ml. To determine the effect of glutaraldehyde, 5, 10, 20, 30, 40 and 50% concentration was used. All the PDMS blocks were immersed for 10, 20 and 30 minutes. The water contact angle was measured on all the PDMS surfaces, including a clean surface as a control. This analysis was done using a drop shape analyzer, DSA 100 machine. The PDMS surfaces were further analyzed by Fourier Transform InfraRed (FTIR spectroscopy), using a Pelkin-Elmer FT-IR spectrometer. PDMS blocks which were pre-immersed in 5% glutaraldehyde and then in BSA and lipase solutions, respectively, were also added for FTIR analysis. The water surface tension was measured for both BSA and lipase and interfacial tension was measured for glutaraldehyde, using the DSA 100. The results indicated that the water contact angle decreases after the PDMS surface has been immersed in all the solutions prepared. FTIR analysis showed new peaks on the PDMS surface immersed in BSA, and in BSA and glutaraldehyde; however, there were no peaks formed on the PDMS surface immersed in lipase and washed, in glutaraldehyde, and in lipase and glutaraldehyde together. Surface tension measurements showed that BSA and lipase decreases the surface tension of water. Interfacial tension measurements also showed that glutaraldehyde decreases the interfacial tension of oil. BSA, lipase and glutaraldehyde therefore decrease the hydrophobicity of the PDMS surface. BSA adsorbs on the PDMS surface and the adsorption is irreversible. The adsorption of lipase on the PDMS surface is reversible. Glutaraldehyde does not adsorb on the surface or the adsorption is not detectable. BSA, lipase and glutaraldehyde all have surface active properties. The CMC value of BSA is 50mg/ml and of lipase is 15mg/ml.

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Borzomato, Joanna Kay. "The effect of glycoconjugate addition on the targeting specificity of Bovine Serum Albumin microspheres in the gastrointestinal tract". Thesis, Liverpool John Moores University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310114.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Crandall, Cruz Marissa Katie. "THE ANALYSIS OF BOVINE SERUM ALBUMIN BINDING AFFINITY FOR XENOGRAFT COMPARED TO A SYNTHETIC PARTICULATE BONE GRAFT MATERIAL". Master's thesis, Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/380305.

Testo completo

Abstract (sommario):

Oral Biology
M.S.
WORKING HYPOTHESIS: Binding of albumin to various bone graft materials is correlated with the surface porosity of these materials, and therefore the binding of albumin to xenograft is stronger than its binding to synthetic bone graft. NULL HYPOTHESIS: There is no significant difference in the binding strength of albumin to xenograft than its binding to synthetic bone graft materials. Objectives: The increased availability of commercially produced bone graft materials versus autogenous bone makes these materials a desirable product in guided bone and tissue regeneration procedures. The use of commercially produced bone graft materials also provides the opportunity of the addition of certain biologic materials in order to enhance the healing response and to overcome the predominantly inactive nature of most graft materials on the market. The development of an adequate carrier of biologic agents is a crucial step in the creation of a bioactive graft material. This study uses an easily manipulated model protein to study specific characteristics of protein binding and release on two different bone graft substrates commonly used as calcified scaffolds in guided bone and tissue regeneration. This experiment was completed as a first phase in the establishment of a protocol for the future investigation of other relevant proteins that may be important in bone and tissue regeneration. Methods: Bovine serum albumin (BSA) dissolved in physiologic buffered saline solution was poured over 100 mg of either xenograft or synthetic particulate grafting material, and incubated for 24 hrs. at 4°C. The quantity of BSA protein adsorption to the grafting material surface was determined by removing all liquid from the wells after the 24 hr. incubation period, followed by quantification of protein concentrations using the bicinchoninic acid (BCA) protein assay reagent kit. In order to analyze the kinetics of protein release, 1 ml of phosphate-buffered saline (PBS) wash was added to all wells, stirred and removed from each well. This was followed by the addition of 1 ml PBS to all wells and removal of 1 ml of liquid at intervals of 1, 3, and 7 days. Protein concentrations were quantified using the BCA protein assay, and the results were analyzed using a two-way ANOVA. Scanning electron microscopy was performed on samples of xenograft and synthetic graft particles prior to BSA exposure, as well as at days 1 and 7 following the initial 24 hr. incubation and the subsequent PBS wash. Energy-dispersive X-ray spectroscopy was also used to analyze the elemental components of the xenograft and synthetic graft material after BSA treatment. Results: Scanning electron microscopy revealed a more porous surface texture and collagenous appearance of the xenograft graft material, versus the synthetic graft. The energy-dispersive X-ray spectroscopy showed a noteworthy difference between the elemental composition of the xenograft and synthetic graft material. A lower concentration of protein was shown in solution after the initial 24 hr. incubation period in the xenograft samples possibly indicating that more protein was bound to the xenograft particles than the synthetic bone. The remaining solution from the xenograft samples throughout the kinetics of release analysis showed more albumin protein released over time as compared to the synthetic graft samples. Conclusions: This study revealed that xenograft material showed a more porous surface structure and greater binding affinity for bovine serum albumin as compared to the synthetic material. The protocol described in this study is a useful model system for future studies to investigate other proteins involved in wound healing, bone remodeling, and angiogenesis. Protein binding and kinetics of release should be explored on alternative mineralized scaffolds or carrier systems in order to determine an adequate delivery mechanism that allows for sustained release during the optimum time frame for modulation of the healing process. Future experiments should focus on identification of an ideal transport medium for bioactive agents that will direct cells into the osteogenic process to restore new bone and periodontal supporting tissues. The engineering of a material that has the quality of extended release of proteins necessary for the healing cascade has the potential to unlock the key to periodontal regeneration.
Temple University--Theses

Gli stili APA, Harvard, Vancouver, ISO e altri

22

WAKABAYASHI, TAKASHI, TETSUO HAYAKAWA, KAYO ADACHI e YUZO SAKAI. "Isolation and Some Biochemical Properties of Porcine Pancreas Mitochondria". Nagoya University School of Medicine, 1992. http://hdl.handle.net/2237/17521.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

23

Subramanian, N. "Immunochemical Studies on the family of Biotin Binding Proteins". Thesis, Indian Institute of Science, 1994. https://etd.iisc.ac.in/handle/2005/113.

Testo completo

Abstract (sommario):

Investigations detailed in this thesis constitue a part of continuing programme of research work undertaken in this laboratory on vitamin binding proteins. Avidin from the chicken egg white, streptavidin &om the bacterium Streptromyces avidin and biotin binding proteins (BBP-I and BBP-11) from chicken egg yolk constitute a family of proteins that bind the vitamin biotin with extremely high affinities. The yolk BBPs are involved in the deposition of the vitamin in the developing oocyte in chicks whereas an antimicrobial function has been attributkl to avidin.. The fact that all these proteins bind the vitamin in the same manner, unlike biotin-dependent enzymes, indicates that the structural features involved in ligand binding could be similar, if not identical in these proteins. To delineate the basis of putative structural similarity among these proteins, studies were carried out using antibodies as the immunological probes. Avidin, a homotetremer glycoprotein, with a subunit Mr of 17,000 has been purified to homogeneity from chicken egg white using a novel procedure involving ammonium sulphate fractionation, ethanol precipitation and S-Sepharose column chromatography. Despite their lesser abundance in chicken egg yolk associated with a large amount of interfering lipids during the purification, both BBP-I (monomer and shown to be precursor for BBP-11) and BBP-I1 (tetramer) have been purified to homogeneity by employing a common method using butanol extraction to remove the lipids, DEAE-Sephacel column chromatography, biotin-AH-Sepharose affinity chromatography and fast performance liquid chrometography (FPLC) system. The purity of all these proteins was confirmed by SDS-PAGE analysis.

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Subramanian, N. "Immunochemical Studies on the family of Biotin Binding Proteins". Thesis, Indian Institute of Science, 1994. http://hdl.handle.net/2005/113.

Testo completo

Abstract (sommario):

Investigations detailed in this thesis constitue a part of continuing programme of research work undertaken in this laboratory on vitamin binding proteins. Avidin from the chicken egg white, streptavidin &om the bacterium Streptromyces avidin and biotin binding proteins (BBP-I and BBP-11) from chicken egg yolk constitute a family of proteins that bind the vitamin biotin with extremely high affinities. The yolk BBPs are involved in the deposition of the vitamin in the developing oocyte in chicks whereas an antimicrobial function has been attributkl to avidin.. The fact that all these proteins bind the vitamin in the same manner, unlike biotin-dependent enzymes, indicates that the structural features involved in ligand binding could be similar, if not identical in these proteins. To delineate the basis of putative structural similarity among these proteins, studies were carried out using antibodies as the immunological probes. Avidin, a homotetremer glycoprotein, with a subunit Mr of 17,000 has been purified to homogeneity from chicken egg white using a novel procedure involving ammonium sulphate fractionation, ethanol precipitation and S-Sepharose column chromatography. Despite their lesser abundance in chicken egg yolk associated with a large amount of interfering lipids during the purification, both BBP-I (monomer and shown to be precursor for BBP-11) and BBP-I1 (tetramer) have been purified to homogeneity by employing a common method using butanol extraction to remove the lipids, DEAE-Sephacel column chromatography, biotin-AH-Sepharose affinity chromatography and fast performance liquid chrometography (FPLC) system. The purity of all these proteins was confirmed by SDS-PAGE analysis.

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Sousa, José Silva de. "Funcionalização da superfície de nanopartículas superparamagnéticas encapsuladas por quitosana para a imobilização de proteínas". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-15092011-145900/.

Testo completo

Abstract (sommario):

A nanociência e a nanotecnologia vêm abrindo inúmeros desenvolvimentos de dispositivos e sistemas em escala nanométrica, com novas organizações moleculares, propriedades e funções distintas. Nesse contexto, as nanopartículas magnéticas poliméricas são compósitos formados por materiais magnéticos com tamanhos de partículas entre 1 e 100 nm combinados com polímeros funcionais. São materiais bem conhecidos e têm sido amplamente estudados devido às suas aplicações em diversas áreas tecnológicas. Nas áreas biológica e médica, as aplicações incluem separação e imobilização de enzimas e proteínas, melhoria nas técnicas de imagem de ressonância magnética para diagnóstico e sistemas de liberação controlada de fármacos. Neste trabalho, proteínas foram imobilizadas na superfície de um biopolímero combinado com partículas superparamagnéticas de magnetita para formar o compósito magnético. Utilizou-se o biopolímero quitosana, reticulada e funcionalizada com glutaraldeído, aplicável em ensaios biológicos. Obtiveram-se 3 tipos de compósitos magnéticos, os quais foram nomeados QM1Glu, QM2NaGlu e QM3Glu. Foram caracterizados por difratometria de raios X, microscopia eletrônica de varredura, magnetometria de amostra vibrante, calorimetria exploratória diferencial, termogravimetria e espectroscopia por infravermelho. Foram avaliados quanto à imobilização das proteínas albumina de soro bovino (SAB), colágeno e tripsina. A imobilização das proteínas no biopolímero ocorreu em 30 min de incubação. O compósito magnético de quitosana não funcionalizada (QM3) também foi avaliado. Para a tripsina verificou-se que QM3 apresentou maior potencial de imobilização do que QM3Glu. Após 30 dias, QM3-Trip e QM3Glu-Trip ainda apresentavam a tripsina ativada. Foram demonstradas a atividade e a cinética enzimática da QM3Glu-trip com o substrato BApNA.
Nanoscience and nanotechnology have opened up numerous developments of devices and systems on the nanometer scale, with new molecular organization, properties and functions. In this context, the polymeric magnetic nanoparticles are composites formed by magnetic materials with a particle size between 1 and 100 nm combined with functional polymers. They are well-known and have been widely studied because of its applications in various technology areas. Applications on the biological and medical areas include separation and immobilization of enzymes and proteins, improved techniques of magnetic resonance imaging and diagnostic systems for controlled drug delivery. In this work, proteins were immobilized on the surface of a biopolymer combined with superparamagnetic particles of magnetite. The biopolymer chitosan was used, cross-linked and functionalized with glutaraldehyde, applicable to the biological assays. Three types of magnetic composites were obtained, which were called QM1Glu, QM2NaGlu and QM3Glu. They were characterized by X-ray diffraction, scanning electron microscopy, vibrating sample magnetometry, differential scanning calorimetry, thermogravimetry and infrared spectroscopy. They were evaluated concerning the immobilization of the proteins bovine serum albumin (BSA), collagen and trypsin. The study showed that the immobilization of proteins on the biopolymer occurred in 30 min of incubation. The magnetic composite of nonfunctionalized chitosan (QM3) was also evaluated. For trypsin, it was found that the immobilization potential of QM3 was higher than that observed for QM3Glu. After 30 days, the trypsin of the QM3-Trip and QM3Glu-Trip was still with activity. The activity and the enzyme kinetics of the QM3Glu-Trip with the substrate BApNA were demonstrated.

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Dasgupta, Sudip. "Nanostructured hydroxyapatite and tricalcium phosphate based ceramics for bovine serum albumin protein delivery and bone implants using microwave sintering". Online access for everyone, 2008. http://www.dissertations.wsu.edu/Dissertations/Summer2008/S_Dasgupta_073008.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Adams, James David. "Heat-induced gelation of proteins". Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/heatinduced-gelation-of-proteins(26efedff-3539-4a27-beb1-3c0e1e76e45a).html.

Testo completo

Abstract (sommario):

In this study the heat-induced gelation of two (readily available) proteins, which contain disulphide bonds, has been investigated over a range of protein concentrations in the presence and absence of the presence of the reductant, dithiothreitol at neutral pH. The proteins selected in this study were: β-Lactoglobulin and bovine serum albumin. These proteins have different number of disulphide bonds and possess different protein secondary structures. The influences of the reductant and protein concentration on their heat-induced gelation were explored to see whether the proteins were able to form protein hydrogels and that the mechanical properties of the resulting protein hydrogels were controllable. The tilting test tube method revealed that both proteins formed macroscopic hydrogels, at protein concentrations above the critical gelation concentration and that the critical gelation concentration was constantly lower in the presence of the reductant. Micro-DSC revealed that both proteins had completely denatured upon heating and that the denaturation temperature and enthalpy were significantly lower in the presence of the reductant. IR spectroscopy revealed that both proteins undergo major secondary structure transitions that resulted in the formation of fibers that are rich in β-sheet structure upon heating and that the protein lost some secondary structure before any heating and gained more β-sheet structure in the presence of the reductant. Both proteins had partially denatured before any heating in the presence of the reductant and that β-LG underwent aggregation that was accompanied by the loss of native β-sheet structure and the formation of intermolecular β-sheet structure, while that BSA underwent aggregation that was accompanied by the loss of native α-helix structure and the formation of intermolecular β-sheet structure. Cryo-TEM revealed that both proteins formed fibers (10 nm in diameter) that exist as single entities at low protein concentrations and become entangled into macroscopic networks, at protein concentrations above the critical gelation concentration and that more fibers and denser macroscopic networks were formed in the presence of the reductant. Oscillatory rheology revealed that both proteins formed macroscopic networks exhibit viscoelastic behaviour and that their elastic modulus had increased in the presence of the reductant and with increasing protein concentration.

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Thomas, Wendy Evelyn. "Shear stress enhances bacterial adhesion /". Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/8056.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Junior, Virgilio Tattini. "Efeito da liofilização sobre a estrutura e mudanças de fase da albumina bovina modificada por reação com metoxi-polietilenoglicol". Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/9/9134/tde-19092006-194927/.

Testo completo

Abstract (sommario):

A conjugação por polietilenoglicol (PEG) mascara a superfície das proteínas e aumenta o tamanho molecular do polipeptídio, reduzindo assim sua ultrafiltragem renal, impedindo a aproximação de células processadoras de antígenos ou anticorpos e reduzindo a degradação por enzimas proteolíticas. O PEG transfere para as moléculas suas propriedades físico-químicas e, conseqüentemente, modifica também a biodistribuição e a solubilidade de drogas peptídicas e não peptídicas. As soluções de proteínas são facilmente desnaturadas (muitas vezes irreversivelmente) pelo aparecimento de numerosos eventos que podem afetar a estabilidade das soluções, tais como: aquecimento, agitação, congelamento, mudanças no pH e exposição a interfaces ou agentes desnaturantes, resultando geralmente na perda da eficácia clínica e aumento do risco de efeitos colaterais adversos. A solução prática para o dilema da estabilidade da proteína é a remoção da água. A liofilização é o método mais comumente utilizado para a preparação de proteínas desidratadas, as quais, teoricamente, devem apresentar uma estabilidade adequada por um longo período de armazenagem em temperaturas ambientes. A proteína utilizada neste estudo foi a albumina sérica bovina (BSA), amplamente estudada no campo da bioquímica. Através da espectroscopia Raman associada com análise térmica por DSC, análise colorimétrica, e a determinação do teor de umidade, verificou-se que o congelamento rápido (30 °C/min.) favoreceu a manutenção da estrutura conformacional da proteína após a liofilização, porém aumentou o tempo de secagem primária em sete horas em relação ao congelamento lento (2,5 °C/min.). Após a modificação da albumina bovina por reação com o metoxi-PEG verificou-se que a BSA-PEG (1:0,25) apresentou um menor grau de alteração estrutural e conseqüentemente uma menor variação das características físico-químicas, além de otimizar as condições de liofilização e armazenamento da proteína quando comparada com a BSA-PEG (1:0,5) .
PEG conjugation masks the proteins surface and increases the molecular size of the polypeptide, thus reducing its renal ultrafiltration, preventing the approach of antibodies or antigen processing cells and reducing the degradation by proteolytic enzymes. The PEG conveys to molecules its physico-chemical properties and therefore modifies also biodistribution and solubility of peptide and non-peptide drugs. This property opens new techniques in biocatalysis and in pharmaceutical technology where many insoluble drugs are solubilized by PEG conjugation and thus more easily administered. Aqueous protein solutions are readily denatured (often irreversibly) by numerous stresses arising in solution, e.g., heating, agitation, freezing, pH changes, and exposure to interfaces or denaturants, usually resulting in lost of clinical efficacy and increase the risk of adverse side effects. Even if its physical stability is maintained, a protein can be degraded by chemical reactions (e.g., hydrolysis and deamidation), many of which are mediated by water. The practical solution to the protein stability dilemma is to remove the water. Lyophilization is most commonly used to prepare dehydrated proteins, which, theorecally, should have the desired long-term stability at ambient temperatures. The protein used in this study was the bovine serum albumin (BSA), largely studied in the biochemical field. Through Raman spectroscopy associated with thermal analysis using DSC, Colorimetric analysis and the determination of water content It was observed that the fast freezing (30 °C/min.) favored the maintenance of the conformational structure in the protein after lyophilization, however increased the primary drying in seven hours with regard to the slow freezing (2,5 °C/min.). After the modification of bovine serum albumin with methoxy-PEG it was observed that the BSA-PEG (1:0,25) showed a lower degree of structural alterations and consequently a lower variation on the physical-chemical characteristics, moreover optimized the conditions during the lyophilization process and storage of the protein when it was compared to BSA-PEG (1:0,5).

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Ribeiro, Alessandra Medeiros. "Estudo espectrosc?pico da intera??o entre flavon?ides e albumina s?rica bovina (ASB)". Universidade Federal Rural do Rio de Janeiro, 2010. https://tede.ufrrj.br/jspui/handle/jspui/1737.

Testo completo

Abstract (sommario):

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-06-06T12:34:21Z No. of bitstreams: 1 2010 - Alessandra Medeiros Ribeiro .pdf: 4846590 bytes, checksum: 525d2754e1be01d1117fe6e9f3362d1f (MD5)
Made available in DSpace on 2017-06-06T12:34:21Z (GMT). No. of bitstreams: 1 2010 - Alessandra Medeiros Ribeiro .pdf: 4846590 bytes, checksum: 525d2754e1be01d1117fe6e9f3362d1f (MD5) Previous issue date: 2010-03-19
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES, Brasil.
Spectroscopic studies for several comercial flavonoids (flavone (FVA), alphanaphthoflavone (?-NAF), beta-naphthoflavone (?-NAF), thioflavone (TFA), S,Sdioxythioflavone (SDF), flavanone (FNA) and quercetin (QUE)), natural flavonoids (biflavonoids such as agatisflavone (ATF), 7?-O-methylagatisflavone (OMA), amentoflavone (AMF) and (DOF)) and thiochromanone (TCR) were performed in different solvents (acetonitrile (ACN), ethanol (ETOH), cyclohexane (CEX), dichloromethane (DCM) and milli-Q water (AD)). Irradiation of TFA, SDF and TCR in acetonitrile, employing the nanosecond laser flash photolysis, lead to the formation of their corresponding triplet excited state. Fluorescence emission spectroscopy studies showed that commercial and natural flavonoids and thiochromanone are not fluorescent. UV/visible spectroscopy studies for QUE, ATF, OMA, AMF and DOF, in the same previous solvents, revealed that for these flavonoids the ground-state absorption spectrum in polar solvents, such as water or PBS (pH=7.4), is completely different than the obtained in dichloromethane. This difference is more pronounced for ATF. For DOF the absorption spectrum in water shows remarkable variations when compared to that in PBS. The interaction between BSA and the flavonoids QUE, ATF, OMA, AMF and DOF in PBS solution, pH = 7.4, was studied by UV/visible spectroscopy, fluorescence emission spectroscopy, circular dicroism and molecular modelling. From these studies it was clearly demonstrated that the interaction observed was directly dependent on the flavonoid concentration and almost independent on temperature variation. The ground state absorption spectrum for BSA showed a hypsochromic effect on the absorption band around 208 nm, corresponding to the n?* transition of the BSA ?-helix structure, as a function of flavonoid concentration. Similar behavior was observed for the absorption at 280 nm, corresponding to the tryptophan absorption in BSA. The fluorescence emission spectrum for BSA in the presence of QUE, ATF, OMA, AMF and DOF, in PBS, at T = 22?C, 27?C, 32?C, 37?C and 42?C, shows a blue-shift on the protein emission as a function of flavonoid concentration. These results suggest that the BSA chromophore is in a more hydrophobic environment when compared with that sensed by the protein in the absence of the flavonoid. In this case, quenching of BSA fluorescence (tryptophan residues) was clearly observed with the high values obtained for the quenching rate constant kq (? 1013 to 1014 L/mol.s) indicating a static quenching process. The distance (r) observed for the tryptophan residues and the flavonoids was smaller than 7 nm, which indicates that there is a reasonable probability for a non-radiative energy transfer process between tryptophan and the flavonoids, based on the F?rster theory for energy transfer. Circular dicroism results at T = 25?C, 37?C and 42?C revealed a significant decrease on the ?-helix percentage for BSA at 208 nm and 222 nm, corresponding to the n?* transition for the secondary structure of BSA, as a function of flavonoid concentration. These effects can be attributed to the formation of a complex BSA/flavonoid which can induce conformational variations on the BSA structure. Molecular modelling indicates that the main regions for the interaction between flavonoids and ASB are located in hydrophobic cavities on the sub-domains IB and IIA, which contain tryptophan residues (Trp-158 and Trp-237). A large hydrophobic cavity containing the Trp-237 is present in the sub-domain IIA, which is responsible for the formation of the complex flavonoid-BSA through a strong interaction flavonoid-tryptophan.
Estudos espectrosc?picos para diversos flavon?ides comerciais (flavona (FVA), alfanaftoflavona (?-NAF), beta-naftoflavona (?-NAF), tioflavona (TFA), S,S-di?xidotioflavona (SDF), flavanona (FNA) e quercetina (QUE)), flavon?ides naturais (biflavon?ides como agatisflavona (ATF), 7?-O-metilagatisflavona (OMA), amentoflavona (AMF) e diidroochnaflavona (DOF)) e tiocromanona (TCR), foram realizados em diferentes solventes (acetonitrila (ACN), etanol (ETOH), cicloexano (CEX), diclorometano (DCM) e ?gua millliQ (AD)). A irradia??o de TFA, SDF e TCR, em acetonitrila, por fot?lise por pulso de laser de nanossegundo, levou ? forma??o de seus respectivos estados excitados triplete. Por espectroscopia de fluoresc?ncia, verificou-se que os flavon?ides comerciais e naturais, e a tiocromanona n?o apresentam emiss?o de fluoresc?ncia. Por espectroscopia de absor??o no ultravioleta/vis?vel (UV-Vis) para QUE, ATF, OMA, AMF e DOF, nestes solventes, percebeu-se que os espectros em presen?a de solventes polares, como AD, foram bem diferentes dos espectros em DCM, principalmente, para ATF, e os espectros em solu??o de tamp?o PBS (pH = 7,4) foram semelhantes aos em AD, exceto para DOF, apresentando mudan?as substanciais. A intera??o entre ASB e os flavon?ides (QUE, ATF, OMA, AMF e DOF) em solu??o tamponada (PBS, pH = 7,4) foi estudada por espectroscopia no ultravioleta/vis?vel, espectroscopia de emiss?o de fluoresc?ncia, dicro?smo circular e modelagem molecular sendo diretamente dependente da concentra??o adicionada de flavon?ides e muito pouco dependente com a varia??o da temperatura. No UV-Vis ocorreu deslocamento para o azul das bandas de absor??o pr?ximas a 208 nm (correspondente a ASB, referente ?s transi??es n?* da estrutura ?-h?lice da albumina) e 280 nm (correspondente ao triptofano da ASB), em fun??o do aumento de concentra??o dos flavon?ides. Na espectroscopia de fluoresc?ncia (T = 22?C, 27?C, 32?C, 37?C e 42?C) houve deslocamento para o azul na emiss?o da prote?na com o aumento da concentra??o dos flavon?ides, sugerindo que o crom?foro da ASB est? em um ambiente mais hidrof?bico em rela??o ?quele quando para ASB livre. Neste caso, observou-se supress?o da fluoresc?ncia de ASB (res?duos de triptofano), como consequ?ncia de um processo de supress?o est?tica como demonstrado pelos altos valores observados para kq (? 1013 a 1014 L/mol.s). A dist?ncia entre os res?duos de triptofano e os flavon?ides (r) foi menor que 7 nm, um indicativo da grande probabilidade de ocorrer transfer?ncia de energia entre ASB e flavon?ides, de acordo com a teoria de transfer?ncia de energia n?o-radiativa de F?rster (Teoria de F?rster). No dicro?smo circular (T = 25?C, 37?C e 42?C) foi verificada uma diminui??o do % de ?-h?lice da ASB em 208 nm e 222 nm (regi?es de transi??o n?* da estrutura secund?ria ?-h?lice da ASB no espectro de absor??o UV), devido ao aumento de concentra??o dos flavon?ides. Esses efeitos podem ser atribu?dos ? forma??o de um complexo flavon?ide-ASB que pode estar induzindo varia??es conformacionais na ASB. Por modelagem molecular, atrav?s do programa docking, percebeuse que as regi?es principais para a liga??o dos flavon?ides com os s?tios de liga??o da ASB est?o localizadas em cavidades hidrof?bicas nos subdom?nios IB e IIA (consistentes com os s?tios I e II) e os res?duos de triptofano (Trp-158 e Trp-237) de ASB est?o nesses subdom?nios, respectivamente. Existe uma grande cavidade hidrof?bica presente no subdom?nio IIA, onde os flavon?ides podem se ligar com o res?duo de triptofano Trp-237 (melhor s?tio de liga??o), formando o complexo flavon?ide-ASB.

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Ferreira, Ernando Silva. "Interação da proteína albumina do soro bovino (BSA) com substratos sintéticos". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-22072010-102300/.

Testo completo

Abstract (sommario):

A interface formada por materiais biológicos e materiais sintéticos tem grande importância em aplicações biomédicas, tais como o desenvolvimento de biomateriais para implantes médicos, que tem como processo essencial a deposição de proteínas na superfície dos biomateriais, e ainda não é bem compreendido no nível molecular. Algumas proteínas sofrem mudanças conformacionais após a adsorção na interface sólido-líquido, afetando suas funções ou propriedades, e algumas técnicas podem medir mudanças conformacionais em interfaces sólido. É possível estudar a fluorescência intrínseca de proteínas: a posição do máximo na faixa espectral da fluorescência, a eficiência quântica e o tempo de vida de fluorescência são indicadores de mudanças no ambiente local de grupos de moléculas de proteína fluorescente. Por outro lado, Nanopartículas de ouro têm atraído muita atenção pela sua afinidade com materiais biológicos e suas propriedades ópticas. Nesta tese, estudamos a viabilidade de substratos de vidro, quartzo, mica e ITO (óxido de índio e estanho) modificado com quitosana, phtalocyanines (Ni, Fe e Ni) e poli(alilanina hidroclorada) (PAH) na adsorção de BSA em forma dos filmes produzidos pela técnica camada por camada. O sistema foi estudado por UV-Vis e espectroscopia de fluorescência estática e resolvida no tempo. A caracterização morfológica dos filmes foi realizada por microscopia de força atômica e microscopia óptica. Os resultados mostram que os filmes de BSA / HAP cresceram com eficiência quatro vezes maior do que os filmes feitos de quitosana, que o quartzo tem a melhor janela de trabalho de UV-vis e há uma relação entre o pH da BSA e o tempo vida de fluorescência do filme resultante. As nanopartículas de ouro foram produzidas pela redução química e estabilizada por quatro diferentes métodos. O crescimento das nanopartículas foi monitorado por UV-vis spectroscopy. A carga de superfície das nanopartículas e da BSA foi estimado em vários valores de pH por medidas de potencial zeta. Os resultados indicaram que as nanopartículas têm cargas negativas na faixa de pH estudada. Soluções de BSA foram preparadas em diferentes valores de pH, e levadas para interagir com as nanopartículas de ouro. Os dados de supressão de fluorescência da BSA mostraram uma maior afinidade da BSA com nanopartículas estabilizadas com sacarose, com pH próximo do ponto isoelétrico (IP) estimado para BSA.
The interface formed by biological materials and synthetic materials has great importance in biomedical applications such as the development of biomaterials for medical implants, which has as an essential process of protein adsorption on the surface of biomaterials, and is not yet well understood in the molecular level. Some proteins undergo conformational changes after adsorption at solid-liquid interfaces, affecting their functions or properties, and few techniques can measure conformational changes in solid interfaces. It is possible to study the intrinsic fluorescence of proteins: the position of the maximum in the spectral range of fluorescence, the quantum efficiency and lifetime of fluorescence are indicators of change in the local environment of fluorescent groups of protein molecules. On the other hand, gold nanopartículas have attracted much attention for its affinity with biological materials and their optical properties. In this thesis we study the feasibility of glass substrates, quartz, mica and ITO (Indium tin oxide) modified with chitosan, phtalocyanines (Ni, Fe and Ni) and poly (allylamine hydrochloride) (PAH) on the adsorption of BSA in the form of films produced by the layer by layer technique. The system was studied by UV-Vis and static and time-resolved fluorescence spectroscopy. Morphological characterization of the films was performed by atomic force microscopy and optical microscopy. The results indicate that the films of BSA/PAH grew with efficiency four times greater than the films made of chitosan, that the quartz has the best working window for UV-vis and there is a relationship between the pH of the BSA and lifetime of fluorescence of the resulting film. Gold nanoparticles were produced by chemical reduction and stabilized by four different methods. The growth of nanoparticles was monitored by UV-vis spectroscopy. The surface charge of nanoparticles and the BSA was estimated at various pH values by zeta potential measurements. The results indicated that the nanoparticles have negative charges in the pH range studied. BSA solutions were prepared at various pH values, were taken to interact with gold nanoparticles. Fluorescence quenching data of BSA showed a greater affinity of the BSA with nanoparticles stabilized with sucrose, at pH near the isoelectric point (IEP) estimated for BSA.

Gli stili APA, Harvard, Vancouver, ISO e altri

32

Afonso, Monica Luisa Chaves de Andrade. "Caracterização do aço inoxidável austenítico UNS S31254 em meio de NaCI 0,11 mol L-1 visando seu emprego em implantes ortopédicos". Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/46/46132/tde-07022007-220153/.

Testo completo

Abstract (sommario):

Foi feita a caracterização eletroquímica do aço inoxidável austenítico UNS S31254 em meio de NaCl 0,11 mol L-1 na ausência e presença de soro albumina bovina (BSA) visando seu emprego em implantes ortopédicos. Foram empregadas como técnicas: medidas de potencial de circuito aberto, curvas de polarização, cronoamperometria, EIE, XPS, MEV, EDS e EEO. O comportamento eletroquímico do aço 254 foi comparado com o de outros aços empregados em implantes ortopédicos (ISO 5832-9, ASTM F138, e AISI 316L) na ausência e presença de BSA. O aço 254 se mostrou semelhante ao ISO 5832-9: encontra-se passivado desde o potencial de corrosão até o de transpassivação; a presença de inclusões de óxidos de cálcio e alumínio no aço 254 foi considerada a responsável por um potencial de transpassivação 100 mV menos positivo do que o observado com o aço ISO 5832-9. Foi detectada. além de óxido de Cr(III), a presença de Mo na forma Mo(VI) no filme passivo do aço 254. A ação da BSA, ora passivante ora catalisadora, depende de sua concentração, da natureza do substrato metálico, e do potencial na interfase metal-solução. A BSA modifica o mecanismo de oxidação do aço 254 e inibe seletivamente a dissolução dos seus elementos constituintes, em particular, níquel e cromo.
The electrochemical characterization of UNS S31254 has been made in 0.11 mol L-1 NaCl medium in the absence and presence of bovine serum albumin (BSA) in order to propose its application in orthopaedic implants. The techniques employed were: open circuit potential measurements, polarization curves, chronoamperometry, EIS, XPS, SEM, EDS and EEO. The electrochemical behavior of 254 SS was compared to that observed for ISO 5832-9, ASTM F138 and AISI 316L stainless steels, used in orthopedic implants, in the absence and presence of BSA. 254 SS is similar to ISO 5832-9 SS: it is passivated on the potential range between the corrosion and the transpassivation potentials; the presence of calcium and aluminum oxides can be responsible for the shift of about 100 mV to less positive potentials on the transpassivation potential when compared to ISO 5832-9 SS. The presence of Mo(VI) was detected beside Cr(III) as passivating film for 254 SS. BSA action depends on its concentration, the nature of the metallic substract and on the potential in the metal-solution interphase. BSA changes the oxidation mechanism of 254 SS and promotes the selective dissolution of the elements particularly nickel and chromium.

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Ameseder, Felix [Verfasser], Walter [Akademischer Betreuer] Richtering e Dieter [Akademischer Betreuer] Richter. "Structure and dynamics of the chemically denatured bovine serum albumin protein investigated with neutron scattering / Felix Ameseder ; Walter Richtering, Dieter Richter". Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1195151349/34.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Han, Tzu-Chiang, e 韓子強. "thermally-induced fibrillation of bovine serum albumin". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/68724243602006881681.

Testo completo

Abstract (sommario):

碩士
國立臺灣大學
化學工程學研究所
97
More than twenty different human proteins can fold abnormally into amyloid fibril deposits which may lead to lethal diseases. Despite extensive investigations on amyloid fibril formation, the detail of molecular mechanism remained rather elusive. The current study is aimed at exploring the effect of thermal induced aggrefation of BSA samples at various pH values. Via numerous spectroscopic techniques and transmission electron microscopy, our results showed that bovine serum albumin samples at neutral condition (pH 7.4) and alkaline conditions (pH 9.0, and pH 10.0) can form amyloid fibril at 70oC. However, no obvious aggregation occurred at acidic condition (pH 2.0). In the phase diagram analysis, we find several transition points through the heating processes except for BSA samples at pH 2.0. Our results demonstrate that BSA samples will form intermediates during the fibrillation processes. Moreover, we use several ligands to further probe the structural changes of different domains. It could be concluded from our results that the breakage of the inter-domain between domain I and domain II prohibit the diamerization of BSA molecules and consequently inhibit the aggregation process. According to the results from this study and the literature, we suggest that the fibrillation processes are facilitated by disulfide/thiol exchanges at 70oC at neutral and alkaline conditions. In addition, the breakage of inter-domain at acidic condition may suppress the fibrillation of BSA samples. The outcome from this work may aid in comprehending the molecular mechanisms of fibrillogenesis of BSA at various pH conditions.

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Shu-Fen, Tsai, e 蔡淑芬. "Electrophoresis of Latex Particles with Immobilized Bovine Serum Albumin". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/43969192263216067021.

Testo completo

Abstract (sommario):

碩士
國立臺灣大學
化學工程學研究所
90
The electrophoretic behavior of PMMA/PMAA copolymer latex, which contains carboxyl groups on its surface, covered by bovine serum albumin (BSA) protein was investigated. BSA was covalently immobilized onto latex surface through a pre-adsorption procedure. The variation of the zeta potential of the particle and as a function of the amount of BSA bonding to particle surface was modeled, and a mathematical model proposed. The experimental data revealed that the absolute zeta potential of BSA covered latex particle exhibited a local maximum at 0.03 mg/m2 of immobilized BSA. The presence of the local maximum can be explained by that while the absolute zeta potential increases with the amount of charges associated with a latex particle, which increases with the amount of BSA immobilized, the resistance to liquid flow due to the presence of a BSA layer also increases with the amount of BSA attached. If the amount of BSA immobilized is small, the former dominates, and the absolute zeta potential increases with the amount of BSA immobilized. On the other hand, if the amount of BSA immobilized is large, the latter becomes more significant.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Jiang, Hsiao-Fan, e 蔣筱凡. "Preparation and Characterization of Tiopronin Bovine Serum Albumin Microsphere". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/25016259996367277209.

Testo completo

Abstract (sommario):

碩士
高雄醫學大學
藥學研究所
100
Tiopronin (N-(2-Mercaptopropionyl)-glycine) is a derivative of mercaptopropionic acid known to protect the liver, the detoxification of metabolic system. Also, it can enhance the excretion of heavy metals, lower cysteine concentrations and prevent cataract. In this study, we utilized bovine serum albumin as base to incorporate Tiopronin by using emulsification–heat stabilization technique. The prepared albumin microsphere, with different proportions of the polymers and drugs, were used to explore the relationship between composition of microsphere and properties. Tiopronin loading in microsphere was measured by using high-performance liquid chromatography (HPLC) method. This study employed an optical microscope to observe the particle size distribution and surface properties of microsphere. Furthermore, this study tested the releasing behaviors in different conditions and the degree of liver repair observed in-vivo test. The result shown the formulated microsphere has smooth surface, and the drug loading efficiency is enhanced by increasing the ratio of polymer in formulation. Also, in-vitro test showing increases of the initial releasing rate of Tiopronin by reducing the ratio of polymer in the formulation, but the relative relationship between polymer ratio and particle size of microspheres was not observed. Additionally, the in-vivo test result of Tiopronin albumin microparticles showed no drug target effect. The sixth week after the treatment, it''s shown apparent pharmacological effect, and the effect is similar to Silymarin.

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Chang, Tsung-Hao, e 張宗皓. "The Properties of Terahertz Metamaterial Sensing bovine serum albumin". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/yrzfm6.

Testo completo

Abstract (sommario):

碩士
國立中興大學
奈米科學研究所
106
In this study, we measure the resonance frequency in different concentrations of BSA (bovine serum albumin) in Terahertz Metamaterial. By using the Terahertz spectra frequency shift to analysis the concentration of BSA as a biosensor. In the experiment, the metamaterial is made by gold because it has high Q-factor which is very suitable as a high sensitivity tool for the biological sensor. In addition, we can observe the Terahertz spectra frequency shift as a biosensor by coating different concentration of BSA.

Gli stili APA, Harvard, Vancouver, ISO e altri

38

Singh, Harsh. "Enzymatic degradation of bovine serum albumin nanoparticles for drug delivery". Master's thesis, 2009. http://hdl.handle.net/10048/873.

Testo completo

Abstract (sommario):

Coacervation is a mild process for developing protein NPs. Bovine serum albumin (BSA) NPs formed via this technique were stabilized using poly-L-Lysine (PLL); short interfering ribonucleic acid (siRNA) was used as a model drug for encapsulation. Specific and non-specific degradation of these coated and uncoated BSA NPs were carried using matrix metalloproteinase-2 (MMP-2) and trypsin, respectively. The particles were characterized with atomic force microscopy, zeta-potential, and photon correlation spectroscopy measurements. There was a significant increase in the zeta potential of BSA NPs upon coating. Trypsin digested the uncoated and coated BSA NPs and resulted in higher BSA release from the particles. However, MMP-2 treatment did not result in higher release of BSA from coated NPs despite the cleavability of coated polymer by MMP-2. This study described a method for obtaining BSA NPs in a controllable size range. Such particles showed degradability in the presence of trypsin and could be promising for targeted drug delivery applications.
Chemical Engineering

Gli stili APA, Harvard, Vancouver, ISO e altri

39

Tsai, Chia-yu, e 蔡佳諭. "Studies on the antibacterial activity of mannose-bovine serum albumin". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/9n764b.

Testo completo

Abstract (sommario):

碩士
國立中山大學
生物醫學研究所
102
Our previous study showed that conjugation of carboxyl groups in BSA with p-aminophenyl α-D-mannopyranoside produced Man-BSA. The mannose-conjugated BSA (Man-BSA) could induce the leakage of cellular membrane. Thus, the aim of the present study was to explore whether Man-BSA exerted its antibacterial action against Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria) via its membrane-damaging activity. Man-BSA exhibited a growth inhibition effect on the growth of E.coli and S. aureus, and the antibacterial activity of Man-BSA against S.aureus was higher than that of Man-BSA against E.coli. The Man-BSA bactericidal action on E.coli and S. aureus positively correlated with an increase in membrane permeability in the bacterial cells as evidenced by propidium iodide staining. Consistently, Man-BSA disrupted the integrity of either E.coli or S. aureus bacterial membrane as evidenced by morphological examination using scanning electron microscopy (SEM) analyses. Lipopolysaccharide (LPS) layer destabilization and lipoteichoic acid (LTA) biosynthesis inhibition in the cell wall increased the Man-BSA bactericidal effect on E.coli and S. aureus. The Man-BSA induced leakage and fusion in E.coli and S. aureus membrane-mimicking liposomes. LPS or LTA attenuated membrane-damaging activity of Man-BSA, while Man-BSA showed similar binding capability with LPS and LTA. Taken together, our data indicate that the antibacterial action of Man-BSA is related to its ability to induce membrane permeability.

Gli stili APA, Harvard, Vancouver, ISO e altri

40

Chang, Chung-Huan, e 張崇煥. "Bovine Serum Albumin Detection Based on Blue Phase Liquid Crystals". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/80258086805836943448.

Testo completo

Abstract (sommario):

碩士
國立交通大學
光電系統研究所
105
In this study, it is the first time that blue phase liquid crystals are used for biomedical detection. Because of the Bragg reflection caused by the blue phase liquid crystals, we can observe the change of the blue phase reflection peak from different BSA concentration sample and realize the quantification in liquid crystal biomedical detection. In the experiment, there are two different mixture being investigated and the effects of detection from each mixture are also different. In the first part result of the E7 doped with chiral R5011, the uniform blue phase structure with DMOAP alignment showed sharp Bragg reflection peak and the presence of BSA disturbed the alignment of blue phase liquid crystal, causing the multi-domain lattice structure. In the result, two reflection peak appeared in the spectrum while the BSA concentration was higher than 106 g/mL, or there was only one peak on spectrum and the intensity of the only peak increased as the BSA concentration decreased. The other result was from mixture of E7 doped with S811 and the Bragg reflection peak blue shifted as the BSA concentration increased only if the concentration was lower than 106 g/mL. When the BSA concentration was higher than 106 g/mL, the strong scattering happened induced by the disorder lattice. Thus we used the spectrum of smectic A phase which was appeared at lower temperature in the same mixture to assist in detecting the BSA concentration while the concentration is higher than 106 g/mL.

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Hsiao, Chun-Hao, e 蕭俊豪. "Photoluminescence Studies in BSA(Bovine Serum Albumin)-Coated Gold Nanoclusters". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/48720517443992617962.

Testo completo

Abstract (sommario):

碩士
中原大學
物理研究所
100
In this thesis, we have two parts to present. In the first one, we investigated luminescence mechanism of Bovine Serum Albumin-coated gold nanoclusters by photoluminescence (PL), and time-resolved photoluminescence (TRPL) experiments at different temperatures. In the carrier recombination process, we observed the confinement effect in our sample. By measuring the TRPL at low temperatures, the activation energy at different temperatures can be fitted. We also obtain localized depth of carriers in our sample, suggesting the luminescence mechanism of AuNCs@BSA. In the second part, we explore the effect of rapid thermal annealing (RTA) on the PL of gold nanoclusters. We obtained the carrier recombination time by the TRPL experiments. PL intensity is enhanced by 1.2 time after rapid thermal annealing.

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Chatterjee, Eeti. "Role of ionic liquids on stability of bovine serum albumin". Thesis, 2013. http://ethesis.nitrkl.ac.in/5279/1/411CY2011.pdf.

Testo completo

Abstract (sommario):

Bovine Serum Albumin (BSA) in water and PBS get affected by the introduction of different ionic liquids. The impact of the model ionic liquids, i.e., 1-ethyl-3-methylimidazolium sulfate, 1-ethyl-3-methylimidazolium chloride, and 1-butyl-3-methylimidazolium chloride, on the tryptophan environment (Trp-environment) was determined by using fluorescence technique. The effect of different aprotic ionic liquids with the variations in cations and anions is very much significant. The presence of ionic liquids alters the Trp environment present in BSA, i.e., presence of hydrophobic and longer alkyl chain moieties disrupt the hydrophobic environment of tryptophan in the native BSA structure. Similarly, anions like sulfate and chloride have significant impact. Surprisingly, chloride exerts less disruption towards the Trp-environment compared to sulfate, which violates the Hofmeister series (as per Hofmeister series, sulfate should have more impact on the stability compared to chloride).

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Perven, Sultana. "Effect of hofmeister salts on the compressibility of bovine serum albumin". 2013. http://hdl.handle.net/1993/19451.

Testo completo

Abstract (sommario):

Determination of whether ion specific potassium halides binding with BSA occurred within the experimental conditions was the aim of the study. Ultrasound velocity measurements using a Resoscan system and density measurements using a DMA 5000M density meter were made to analyse BSA conformation in the presence of potassium salts of the Hofmeister series. It was found that the density and the adiabatic compressibility of BSA-potassium halide mixed aqueous solutions cannot be predicted from the density and the adiabatic compressibility of potassium halide solutions and that of BSA solutions. Interaction occurs between BSA and Br-, I- and F- ions in mixed aqueous solutions of BSA-KBr, BSA-KI and BSA-KF, but there is no interaction between BSA and Cl- ion in BSA-KCl mixed aqueous solution. The interaction of ion to BSA is ion non-specific to the Hofmeister series.

Gli stili APA, Harvard, Vancouver, ISO e altri

44

何珮綺. "Diffusion of Bovine Serum Albumin and Vitamin B12 in Dextran Hydrogels". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/84705431757570517215.

Testo completo

Abstract (sommario):

碩士
國立臺灣科技大學
高分子工程系
92
In this study, dextran hydrogels were prepared by polymerization of aqueous solution of glycidyl methacrylate derivatized dextran(dex-GMA). The compressive measurements and thermodynamic equilibrium for chain elasticity and water-polymer mixing results indicate that the effective crosslinking density (ve) increase with increasing the degrees of substitutions and decreasing the water contents of gels. The stress-strain data of hydrogels fitted with the slip-link model indicate that there are significant disentanglements in the network, which is increased with water contents. As the crosslinks decrease and disentanglements increase, the mesh sizes of gels increase. The releases of BSA and Vitamin B12 from hydrogels varying in degrees of substitutions and water contents, are investigated to understand the “free volume of diffusion” and “length of diffusion path” in terms of the molecular parameters of diffusants and gels. In terms of the free volume theory, the slope of logarithm of normalized diffusion coefficients against the inverse hydration of gels increases with the degrees of substitutions of gels, and is nearly proportional to the radius of the solute. In addition, as the water contents decrease, the tortuosity of solutes diffusion in the gels increase. As the ratio of diameter of solutes to mesh sizes of the gels lie between 0.06 to 0.4, a deviation of about 20% between the experimental and predicted values is found. However, there’s a large deviation between the experimental and the predicted values at higher ratio. The regression lines for the tortuosity of Vitamin B12 and BSA can’t overlap with each other, and therefore, it’s believed that the shape in solutes can also affect the tortuosity of solutes diffusion in gels.

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Chen, Be-Fang, e 陳畢帆. "Thermal Denaturation Study of Bovine Serum Albumin using Optical Heterodyne Polarimeter". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/41400930260052428698.

Testo completo

Abstract (sommario):

碩士
國立清華大學
核子工程與科學研究所
98
Abstract Bovine serum albumin (BSA), a highly complex protein, plays important functions in immunology analysis and food science. In the denaturation study of proteins, heat treatments are frequently required for a variety of purposes and they can change the physical, chemical, biological and functional properties of proteins. Therefore, during thermal processing to understand, monitor, and control protein changes, particularly unfolding and refolding are important. There are many methods to detect the structures of protein, such as electrophoresis, X-ray diffraction crystallography, circular dichroism. However, these methods are not easy to monitor the denaturation process of BSA in real time. In this study, we have built up an optical heterodyne polarimeter capable of 12.8-fold of amplification factor in measuring the optical rotation angle and then understand the structure changes of protein. BSA under heat treatment can proceed structure changes. We observed thermal denaturation of BSA by measuring the real-time changes of optical rotation angle and transmission power, and then used electrophoresis to verify the results. For 2.5% (g/ml) BSA solution, the results indicate that BSA begins to denature at 66℃ and then soon goes to an unknown state which can restore the optical rotation angle. The denatured state is a reversible process. When the temperature goes beyond 68℃, BSA solution begins an irreversible aggregation state.

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Wang, Ren-Tsung, e 王仁聰. "Bactericidal mechanism of carboxyl group-modified bovine serum albumin and ovalbumin". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/50865504818499138533.

Testo completo

Abstract (sommario):

碩士
國立中山大學
生物醫學研究所
103
The aim of this study is to investigate the physicochemical properties and antimicrobial activities of semicarbazide-modified bovine serum albumin (BSA) and ovalbumin (OVA). MALDI-TOF and RP-HPLC showed that modification of carboxyl groups caused an increase in molecular weight and hydrophilicity of SEM-BSA and SEM-OVA compared with those of BSA and OVA. CD spectra measurement revealed that modification of carboxyl groups caused a change in the secondary structure of BSA and OVA. SEM-BSA exhibited a growth inhibition on E. coli and S. aureus, while SEM-OVA only shows bactericidal activity against S. aureus. Destabilization of structural stability of lipopolysaccharide (LPS) or inhibition of lipoteichoic acid (LTA) synthesis promoted antibacterial activity of SEM-BSA and SEM-OVA. Propidium iodide (PI) staining indicated that SEM-BSA and SEM-OVA induced membrane permeability of S. aureus. Compared to SEM-BSA, SEM-OVA insignificantly affected the membrane permeability of E. coli. SEM-BSA and SEM-OVA induced membrane fusion and permeability of S. aureus membrane-mimicking vesicles. Unlike SEM-BSA, SEM-OVA did not damage E. coli membrane-mimicking vesicles. Both LPS and LTA suppressed membrane-damaging activity of SEM-BSA and SEM-OVA. SEM-BSA showed higher binding affinity with bacterial membrane-mimicking vesicles compare to SEM-OVA. Moreover, SEM-BSA penetrated into membrane and perturbed the membrane structure. The interacted-mode of SEM-OVA with S. aureus and E. coli membrane-mimicking vesicle differed. Taken together, the antibacterial action of SEM-BSA and SEM-OVA are related to their ability to damage bacterial membrane. The membrane-interacted mode of SEM-OVA may elucidate its inability to display antibacterial activity against E. coli.

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Song, Lei. "Sorption of Bovine Serum Albumin on Nano and Bulk Oxide Particles". 2010. https://scholarworks.umass.edu/theses/391.

Testo completo

Abstract (sommario):

Manufactured oxide nanoparticles (NPs) have large production and widespread applications, which will inevitably enter the environment. NPs can interact with proteins in living beings due to the fact that NPs can transport into blood or across cell membranes into cells. Conformational change of protein molecules after sorption on oxide NPs has been reported. Therefore, it is important to understand the adsorption mechanism of protein onto oxide NPs surfaces. Although few works have reported protein adsorption behaviors, a general systematic comparison of the effects of particle size and surface groups on protein adsorption by widely studied NPs still needs to be made. Moreover, the relationship between adsorption maxima, which are related to protein conformational change and particle toxicity, and protein conformational change has not yet been studied. Therefore, in this work, the adsorption behavior of bovine serum albumin (BSA) protein on three types of nano oxide particles (viz., TiO2, SiO2, and Al2O3) was investigated in order to explore their interaction mechanisms, compared with that on regular bulk particles (BPs). The BSA adsorption maxima on oxide particles were regulated by the surface area of oxide particles. BSA adsorption was primarily induced by electrostatic attraction and ligand exchange between BSA and oxide surfaces. Surface hydrophilicity, surface charge and aggregation of oxide particles also affected their adsorption of BSA. Calculations suggested that a multilayer of BSA covered α-Al2O3, and single layer covered the other oxide particle surfaces. Primary structures of BSA molecules were adsorbed and changed on surfaces of oxide particles.

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Blome, Matthew C. "Characterization of ricin binding to multivalent bovine serum albumin-based neoglycoconjugates". 2008. http://www.etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-2533/index.html.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Shih, You-Yi, e 施攸怡. "Examining the Effects of Glycation on Bovine Serum Albumin and Casein". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/70863229543958990710.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

50

Jena, Dipikapriyadarsini, e Juisa Nandini Patra. "Spectrofluorimetric Investigation of Interaction of Coumarin-1 with Bovine Serum Albumin". Thesis, 2012. http://ethesis.nitrkl.ac.in/3063/1/Juisa_Deepika_Ethesis_final.pdf.

Testo completo

Abstract (sommario):

Serum albumin is the most abundant protein in blood plasma. Many drugs, including anticoagulants, tranquilizers and general anesthetics are transported in the blood while bound to albumin. Coumarins constitute an imported group of natural products that show high binding affinity towards serum albumins. Binding of coumarin-1 (7-N,N-diethylamino-4- methylcoumarin) to bovine serum albumin (BSA) results in seven fold enhancement in its fluorescence intensity, 20 nm blue shift in emission maximum and ten fold increase in fluorescence anisotropy and around four fold increase in the fluorescence lifetime as compared to that in water indicating strong binding efficiency. It shows two binding sites in BSA determined by Job’s plot, and one high affinity site with a larger binding constant (ca. 105 M−1) and other low affinity site with a smaller binding constant (ca. 104 M−1) evaluated from Scatchard plot. The Edsall plot and Bjerrum plot reveal the highly interactive nature of the two binding sites and the site specific ligand displacement experiments suggests the binding of Cou 1 to the warfarin binding site i.e. site I in subdomain IIA

Gli stili APA, Harvard, Vancouver, ISO e altri

Tesi sul tema "Bovine serum albumin"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili