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Kobbi, Sabrine. "Purification de la RuBisCO à partir de la Luzerne, hydrolyse enzymatique, identification, structure-fonction des peptides bioactifs et leur valorisation dans des produits alimentaires". Electronic Thesis or Diss., Lille 1, 2017. http://www.theses.fr/2017LIL10201.
Alfalfa is an excellent source of protein. However, RuBisCO proteins showed most interest. Indeed, this protein has been labelled the most abundant on earth; it constitutes about 65% (w/w) of soluble leaf protein of Alfalfa. In this work, a new method was introduced for the purification of RuBisCO from alfalfa powder 10% (w /v), using two different solvents and pH effect. In a first step, the performance of the proposed RuBisCO recovery method was evaluated through qualitative and quantitative analysis and the results obtained showed that this new method could replace some conventional industrial processes. In a second step, enzymatic hydrolysis was carried out on the purified RuBisCO, which resulted in a large bioactive peptide population. The final peptides after 24h of hydrolysis showed better antibacterial or antioxidant activity compared to the other peptide hydrolysates. Nine new antibacterial peptides have been identified and characterized by MS and have a MIC of 2-6 mM against four species of bacteria: B subtilis, E coli, L innocua and M luteus. In addition, antioxidants peptide fractions were identified in this work, their antioxidant activity was evaluated by various in vitro and in vivo tests on oil of Colza. Finally, the addition of peptide RDRFL derived from the peptic hydrolysis of RuBisCO has a positive effect on the prolongation of the shelf life of minced meat and of tomato puree
Tauzin, Jérôme. "Biofonctionnalités de peptides issus de caséines αs bovines : Cinétique d'hydrolyse trypsique de la caséine αs2 et activité inhibitrice de l'ECA des peptides". Nancy 1, 2003. http://www.theses.fr/2003NAN10224.
αS2-Casein is the less studied substrate to obtain bioactive peptides among the major milk proteins. After its purification by ion exchange chromatography followed by hydrophobic interactions chromatography, it was hydrolysed by trypsin and resulting peptides were identified. Their release kinetics revealed three areas having different susceptibility to proteolysis. These data and secondary structure prediction helped to define a hypothetical model of protein organisation in solution. Four tryptic peptides inhibited angiotensin-I converting enzyme (CEI) with IC50 values comprised between 4 and 15 micro M. Their sequences were confronted with others inhibitors to discuss sequence-activity relationships
Kobbi, Sabrine. "Purification de la RuBisCO à partir de la Luzerne, hydrolyse enzymatique, identification, structure-fonction des peptides bioactifs et leur valorisation dans des produits alimentaires". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10201.
Alfalfa is an excellent source of protein. However, RuBisCO proteins showed most interest. Indeed, this protein has been labelled the most abundant on earth; it constitutes about 65% (w/w) of soluble leaf protein of Alfalfa. In this work, a new method was introduced for the purification of RuBisCO from alfalfa powder 10% (w /v), using two different solvents and pH effect. In a first step, the performance of the proposed RuBisCO recovery method was evaluated through qualitative and quantitative analysis and the results obtained showed that this new method could replace some conventional industrial processes. In a second step, enzymatic hydrolysis was carried out on the purified RuBisCO, which resulted in a large bioactive peptide population. The final peptides after 24h of hydrolysis showed better antibacterial or antioxidant activity compared to the other peptide hydrolysates. Nine new antibacterial peptides have been identified and characterized by MS and have a MIC of 2-6 mM against four species of bacteria: B subtilis, E coli, L innocua and M luteus. In addition, antioxidants peptide fractions were identified in this work, their antioxidant activity was evaluated by various in vitro and in vivo tests on oil of Colza. Finally, the addition of peptide RDRFL derived from the peptic hydrolysis of RuBisCO has a positive effect on the prolongation of the shelf life of minced meat and of tomato puree
Albe, Slabi Sara. "Développement et optimisation d'un procédé extrapolable de production d'isolats de protéines de tournesol". Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0167.
Sunflower meal, by-produced after oil extraction process, is a valuable source of proteins (30−70% on dry matter basis). These proteins are composed of two main fractions: globulins (helianthinins) and albumins (SFA). Thanks to well-balanced amino acid composition and good functional properties, they are considered very promising for human nutrition as protein isolates. However, the literature shows many scientific drawbacks during sunflower protein extraction and purification. These drawbacks lie on interaction between proteins and chlorogenic acid (major hydrosoluble phenolic compound of sunflower), poor extraction yield and helianthinin denaturation during protein purification by acidic precipitation. The goal of this thesis work was to overcome these limitations and to propose a scalable process for production of sunflower protein isolates. The first part of the thesis was based on the development of a new method for simultaneous quantification of proteins, free chlorogenic acid isomers and chlorogenic acid bound to proteins. This analytical tool provided fast and reliable access to performance criteria crucial for further development and optimization of sunflower protein production process. In the second part of the thesis, an optimal condition for extraction of total proteins from sunflower meal allowing maximizing extraction yield and minimizing protein-phenol interaction was searched. For this purpose, multicriteria optimization based on modelling by design of experiments and genetico-evolutionary algorithms was applied. Then, an alternative method for protein purification by ultrafiltration was developed. This part of study has improved the global understanding of sunflower protein extraction process and yielded in a satisfactory product. However, the residual meal produced after protein extraction was poor in proteins and rich in phytic acid (antinutritional factor). The third part of the thesis was therefore focused on the implementation of an alternative strategy of selective extraction of albumins. To do so, the methodology of modelling and multicriteria optimization, used in second part of the thesis, allowed to identify the optimal conditions for selective extraction of albumins with good yield keeping a satisfactory value of the residual meal. The extracted albumins were light-coloured, rich in sulphur-containing amino acids and more soluble than total sunflower proteins. The functional properties of albumins (foaming, emulsifying) were improved or comparable to those of soy proteins. Therefore, the established strategy provided a sustainable process for production of albumins that would be used in human nutrition and residual meal for feed applications
Abou-Diab, Mira. "Production éco-circulaire de peptides antibactériens, antifongiques et antioxydants déminéralisés à partir d'hémoglobine bovine par électrodialyse avec membranes bipolaires : étude de faisabilité, mécanisme enzymatique, optimisation des paramètres, comparaison avec l'hydrolyse conventionnelle et prévention du colmatage". Electronic Thesis or Diss., Université de Lille (2018-2021), 2021. http://www.theses.fr/2021LILUR031.
Bovine cruor, a slaughterhouse waste, is produced in large quantities all around the world. This co-product was mainly composed of hemoglobin, a protein rich in bioactive peptides after its enzymatic hydrolysis. However, during conventional hydrolysis, chemical agents are necessary to adjust/regulate the pH of the solution and the final hydrolysates produced contain high levels of mineral salts. Therefore, in this study, it is proposed to apply, for the first time, a green technology, named electrodialysis with bipolar membrane (EDBM), as an alternative method to the conventional enzymatic hydrolysis of hemoglobin to obtain purified bioactive peptides. The main objectives of the present thesis were to test the feasibility of this new process to produce bioactive peptides from bovine hemoglobin, to establish the optimal conditions, to avoid membrane fouling and to apply a new original « multiple-step » EDMB process allowing the production of demineralized bioactive peptides without the addition of chemical salts. Bipolar/monopolar (anionic or cationic) configurations using the H+ and OH- generated by the bipolar membranes to regulate the pH were investigated and compared to a conventional process using chemical acid and base. The EDBM configuration formed with cationic membranes allowed the production of hydrolysates containing a low concentration of mineral salts but with fouling formation on the cationic membrane, while EDBM configuration formed with anionic membranes allowed the production of hydrolysates without fouling but with a similar salt concentration than the control. Based on these results, a new 3 compartments EDBM configuration was carried-out for denaturing the hemoglobin, inactivating the enzymatic reaction and demineralizing up to 85% the hemoglobin hydrolysate simultaneously. However, a fouling was still observed on the anionic membrane due to hem precipitation. For this reason, an additional step of discoloration was tested before the demineralization to avoid fouling using the electrogenerated acid. The discolored and demineralized peptides recovered showed antioxidant activity, antibacterial activity against many bacterial strains (Gram + and Gram -) and for the first time antifungal activity against many molds and yeasts strains. Moving towards a circular economy, this sustainable technology has found to be effective in performing multiple operations simultaneously and has a great potential for industrial hydrolysis of blood, since it produces purified biopeptides with a low mineral content and can be used as natural preservatives on meat
Rulence, Alexandre. "Mise en œuvre de procédés membranaires pour la séparation sélective de la nisine à partir de surnageants de culture complexes". Electronic Thesis or Diss., Université de Lille (2022-....), 2023. https://pepite-depot.univ-lille.fr/ToutIDP/EDSMRE/2023/2023ULILR034.pdf.
Nisin, a bacteriocin produced by lactic acid bacteria (LAB) presents physicochemical properties such as a thermal resistance and an antimicrobial activity against food pathogens bacteria. Nisin is actually the only bacteriocins labelled as Generally Recognized As Safe (GRAS) by the U.S Food and Drug Administration (FDA) and is thus the only bacteriocin used as a natural preservative in the food industry, making it an interesting alternative to the use of chemical preservatives. However, its uses are hampered at industrial scale due to low yields et high cost linked to its production on commercial broth and its purification necessity the combination of low yields techniques such as salting out coupled with chromatography.In this case we investigated in this work the use of food grade by-product produces by the food industry in replacement of costly commercial broth. Several by-products composed of vegetal and fish peptones were tested for the production of nisin. Whey being the most used by-product employed for production of nisin and several bacteriocin, we tested and compared different vegetal and fish proteins hydrolyzates regarding biomass production and nisin yields obtained. Several vegetal and fish protein hydrolyzates were tested with two different strains of Lactococcus lactis in order to optimize nisin production. Results showed a greater nisin production using L.lactis UL 719 when compared to a commercial strain. Results also showed the efficacy of some vegetal and one fish by-product for the production of nisin when compared to whey medium and commercial broth MRS. During this work was also investigating alternatives for nisin purification. Electro- and pressure-driven membrane process were studied for nisin purification and especially ultrafiltration (UF) and electrodialysis for which no literature reported the use of ED for nisin purification. ED was applied to the purification of nisin from a commercial solution and from a cell-free supernatant produced with whey permeate as broth for fermentation. UF was applied to the purification of nisin from a cell-free supernatant and permit to compare UF and ED in this application. This work enables us to demonstrate nisin interaction with ion exchange membrane never reported and enable its purification with purification factor comparable to conventional method actually used. Moreover, we demonstrated the use of ED not only efficient for nisin purification but with the possibility to implement ED in an eco-circularity concept, from nisin production using by-products, to its purification with ED and the recycling of salts from saline effluent produced during nisin salting-out
Le, Coeur Catherine. "Contribution à l'étude d'un hydrolysat pepsique de myoglobine de muscle squelettique rouge de thon Thunnus Albacares : caractérisation des peptides issus de l'hydrolyse étude de l'association hème-peptide". La Rochelle, 1996. http://www.theses.fr/1996LAROS011.
Ravallec, Rozenn. "Valorisation d'hydrolysats d'origine marine : optimisation de la concentration en peptides apparentés aux facteurs de croissance et aux agents sécrétagogues : essais in vitro et in vivo". Brest, 2000. http://www.theses.fr/2000BRES2041.
Chabanon, Gérald. "Hydrolyses enzymatiques d'isolats protéiques issus de tourteaux de colza : cinétique, modélisation, caractérisation et fonctionnalité des peptides". Vandoeuvre-les-Nancy, INPL, 2005. http://docnum.univ-lorraine.fr/public/INPL/2005_CHABANON_G.pdf.
This thesis made it possible to study obtaining biologically active peptides or with functional properties through the development of processes for the preparation and the hydrolysis of protein isolates resulting from rapeseed cakes. First, a method of preparation of two protein isolates being different by the type of proteins (Globulin or Albumin) was developed. The two isolates do not have good functional properties but their partial hydrolysis by Alcalase 2. 4L improves some of them. Then, the hydrolytic action of commercial proteases (Alcalase 2. 4L, Pronase SG, Neutrase 0. 8L, Prolyve BS, Lypaïne 6500, Orientase 90N, Espérase 7. 5L) on the isolate of globulins was compared. The valorisation of the hydrolysates related to their capacity to promote the growth of animal cells cultivated in a serum-free medium. It was shown that the kinetics of hydrolysis, the size of produced peptides and the biological activity of the hydrolysates are significantly influenced by the specificity of the enzyme and there is a relation enzyme/ degree of hydrolysis (DH)/ targeted activity. Lastly, we showed for three different enzyme/substrate systems (Alcalase / Globulin, Pronase / Globulin and Alcalase / Albumin) that at given DH and pH, the peptide composition of the hydrolysates is independent of the initial enzyme and substrate concentrations and of the temperature. Thus, the prediction of the temporal evolution of the DH, whatever the values of precedent parameters, allows to control the generation of a peptide mixture with targeted properties. A model based on the reaction pathway of Michaelis-Menten was then built in order to simulate the hydrolysis kinetics in batch reactor. For that, limiting phenomena implied in the hydrolysis (inhibition or inactivation of the enzyme, modification of the substrate) were highlighted
Debrabant, Alain. "Étude de la protéolyse de la protéine P126 de Plasmodium falciparum". Lille 1, 1990. http://www.theses.fr/1990LIL10067.
Odoux, Eric. "Contribution à l'étude de l'hydrolyse de la glucovanilline en vanilline dans la "gousse" du vanillier (vanilla planifolia G. Jackson)". Montpellier 2, 2004. http://www.theses.fr/2004MON20057.
Prévôt-d'Alvise, Nathalie. "Mise au point d'un procédé d'hydrolyse enzymatique de protéines de luzerne (Medicago sativa var. Europe) dans un réacteur à membrane et extrapolation à l'échelle pilote". Lille 1, 2000. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2000/50376-2000-47.pdf.
Gevrey, Jean-Claude. "Mécanismes de réponse de la cellule endocrine intestinale aux hydrolysats protéiques : aspects sécrétoire et transcriptionnel". Lyon 1, 2002. http://www.theses.fr/2002LYO1T170.
Giardina, Thierry. "Purification, caractérisation et relation structure-fonction de l'acylase I de l'entérocyte de porc". Aix-Marseille 3, 1997. http://www.theses.fr/1997AIX30047.
Moyne, Pascale. "Contribution à l'étude de l'apport azoté en nutrition parentérale par des hydrolysats enzymatiques de protéines du lait de vache". Montpellier 1, 1994. http://www.theses.fr/1994MON13510.
Vinot-Renaud, Catherine. "Contribution à la connaissance et à la valorisation d'hydrolysats industriels de protéines de poissons". Compiègne, 1989. http://www.theses.fr/1989COMPD208.
Robert, Marie. "Développement d'hydrolysats pour l'alimentation des animaux d'aquaculture : caractérisation moléculaire et fonctionnelle". Caen, 2014. http://www.theses.fr/2014CAEN2050.
Global production of farmed fish and shrimp has grown dramatically over the past decades and now contributes to half of the aquatic products intended for human consumption. Aquaculture is a key sector for the maintenance and improvement of food security worldwide. However, its rapid growth has a significant impact on the environment, particularly on the stocks of wild fish used to produce aqua feed. In this context, aqua feed has dramatically evolved and has been adapted to many economic and environmental constraints. The use of fishmeal has particularly declined in favor of plant protein sources. But plant proteins are less adapted to the nutritional needs of fish and result in lower growth performances. Protein hydrolysates from fishing and aquaculture by-products are ingredients of high nutritional and bioactive potential developed to restore growth performances in high-level plant protein diets. They are rich in hydrolytic peptides and free amino acids, but they are complex mixtures whose composition is not well known. We developed an experimental approach to characterize the peptide fraction of two by-product hydrolysates based on two complementary approaches: a transcriptomics approach aimed at getting transcriptomics data about the targeted by-products, and a peptidomics approach. The peptidomics approach combined the optimization of fractionation steps and two complementary mass spectrometry techniques. Thus we identified more than 1,000 peptides in the two by-product hydrolysates. Furthermore, diet conditioning experiments conducted in sea bass, Dicentrarchus labrax, highlighted their interesting nutritional properties to maintain growth performances of farmed fish. Indeed, dietary inclusion of 5\% of these hydrolysates in a high-level plant protein diet (95%) maintained growth performances at similar levels to those obtained with diets containing 80% of plant protein. In addition, we demonstrated an influence of these by-product hydrolysates on the digestive physiology of sea bass, as shown by biomarker expression in the intestinal absorption profiles observed in the study. Finally, our work shows that (i) both hydrolysates possess in vitro antibacterial activity and (ii) tilapia hydrolysate stimulates the immune system of sea bass. These results demonstrate the interest of using these two hydrolysates in aquaculture in addition to or instead of fishmeal
Meynial, Isabelle. "Glycosylation des protéines in vitro par voie enzymatique". Toulouse, INSA, 1994. http://www.theses.fr/1994ISAT0049.
Kriaa, Habib. "Enrichissement du son en protéines par fermentation". Compiègne, 1989. http://www.theses.fr/1989COMPD282.
Proteins are very important for human food. Nevertheless the world shortage in protein is increasing despite all the efforts made to improve productivity of vegetable protein sources. In Tunisia, the bran of the corn is a very abundant raw material. This substrate is poor in proteins, however because of its richness in starch (25 - 30%), this raw material can be enriched in proteins of unicellular organisms in particular by yeast culture. To reach this objective, we’ve used an enzymatic method transforming the starch of the bran in a fermentiscible sugar. The use of amylotic enzymes has allowed us to transform starch in simple sugar with a yield of 95%. The hydrolysate thus obtained has been tested as a culture medium for the growth of Hansenula anomala in batch and continue culture to its enrichment in proteins. The use of that enzymatic hydrolysate of the starch of the bran at 20 (g/l) of glucose for the growth of Hansenula anomala in a closed reactor has led to the following kinetic characteristics : a specific maximal speed : max(x)=0,25h-1 and a protein yield Y(P/s)=22%. The continue culture of this strain on the bran hydrolysate in the same conditions has led to the deduction of the following kinetic characteristics : max(x)=0,3h-1 with a protein yield Y(P/s)=23%
Rivoyre, Matthieu de. "Expression et purification de protéines membranaires mammifères impliquées dans des pathologies". Nice, 2006. http://www.theses.fr/2006NICE4062.
Membrane-bound proteins play a significant role in cell function due to their position in between the cell and the external medium. These proteines are for this reason, involved in a number of human diseases. Knowing membrane-bound proteins will allow us to better understand several biological and pathophysiological functions. Furthermore, their localisations make them interesting therapeutic targets. Knowing the structure of proteins gives a tremendous amount of information on their functions. To date, even if several thousands structures of soluble proteins have been solved; only less than two hundred structures of membrane-bound proteins are known. This important difference is partly due to the fact that membrane-bound proteins are difficult to obtain pure in a stable conformation in order to determine their three-dimensional structures. Recombinant expression of membrane-bound proteins has a high variability depending on the nature of the protein studied. Our research team is therefore interested in the development of recombinant expression and purification strategies of membrane-bound proteins involved in numerous human diseases, in order to study their functions but also to establish structurefunction relationships. My thesis work has focused on the expression and the purification of human receptors of the Hedgehog pathway, Patched and Smoothened. Alteration of these two proteins is known to be involved in numerous cancers but also in some neurological diseases. These two proteins have been expressed in two different systems : yeast cells Saccharomyces cerevisiae and Pichia pastoris and also in drosophila cells S2. We have been able to show that the protein Smoothened is expressed in Pichia pastoris in its native conformation in yeast cells an dit is therefore possible to purify it in order to perform structural studies. Patched and Smoothened have also been stably and functionaly expressed in S2 cells. This system is also interesting to perform comparative studies between drosophila and human proteins
Sarramegna, Valérie. "Solubilisation et purification du récepteur u-opoi͏̈de humain surexprimé dans la levure méthylotrophe pichia pastoris". Toulouse 3, 2002. http://www.theses.fr/2002TOU30034.
Le, Borgne Sylvie. "Conception d'un système d'expression-purification de protéines de fusion par échange d'ions". Toulouse, INSA, 1994. http://www.theses.fr/1994ISAT0023.
Rakotozafy, Randrianasolo Lalatiana Rasata. "Application de réactions enzymatiques énantiosélectives au dédoublement de synthons chiraux utilisables dans l'industrie pharmaceutique ou en chimie fine". Paris 6, 1991. http://www.theses.fr/1991PA066301.
Raphel, Véronique. "Purification et caractérisation de la N-acycleptide hydrolase intestinale de porc". Aix-Marseille 3, 1994. http://www.theses.fr/1994AIX30036.
Garreau, Isabelle. "Les protéines plasmatiques, sources potentielles de peptides biologiquement actifs : purification et caractérisation de peptides apparentés aux enképhalines libérés par hydrolyse enzymatique in vitro". Limoges, 1993. http://www.theses.fr/1993LIMO0186.
Michalke, Kerstin. "Expression, purification and biophysical characterisation of mammalian GPCRs for structural studies". Aix-Marseille 1, 2008. http://www.theses.fr/2008AIX11018.
G protein–coupled receptors represent the largest family of eukaryotic transmembrane signal transduction proteins. Because of their central role in the body, GPCRs are linked to many human diseases and are therefore important targets for therapeutics. The knowledge of high resolution x-ray structures for GPCRs would facilitate the development of those therapeutics. However, because of their hydrophobic nature and their low abundance in the body, only a few GPCR x-ray structures are known. Within the project MePNet, we therefore produced and characterised GPCRs to subject them to cristallisation assays. We have expressed 45 out of 100 GPCRs in inclusion bodies, almost the half of them with high yields. Expression is neither dependent on the expression temperature nor the cystein content nor the size of individual receptors. Gateway vectors appeared to be superiour to pET vectors and C43 proved to be the most successful expression strain. Expression was successfully scaled up in flasks and fermentors. Fermentor expressed huPTH1R and muCB1R were solubilised in SDS and refolded by artificial chaperone assisted refolding, yielding 280mg and 370mg of refolded PTH1R and CB1R per litre fermentor culture, respectively. Native receptor folding was verified by binding tests. For PTH1R/PTH(1-34) interaction a Kd of 6,5 nM was measured by BIAcore and 56 nM by tryptophan fluorescence quenching assay. CB1R showed an affinity of 38,2 nM for inverse agonist [3H]SR141716A and 19,4 nM for agonist [3H]CP 55,940 in the radioligand binding assay. The CB1R preparation contained 30% of active receptor. Analytic SEC coupled to LS/UV/RI detectors showed that the receptor preparations were contaminated with aggregates, which could be reduced by ultracentrifugation and ligand affinity chromatography, and by changing refolding and gelfiltration conditions. PTH1R and CB1R specific camel heavy chain antibodies fragments (vHHs) were generated and characterised by BIAcore. All tested fragments showed receptor binding activities in the nanomolar range (12- 70nM). Epitopes of PTH1R specific vHHs seem neither to overlap one another nor the binding site of ligand PTH (1-34), which might allow the usage of PTH1R/ PTH (1-34)/ vHH complexes with more than one vHH in crystallisation. PTH1R and CB1R were tested in up to 1400 crystallisation condition, none of these leading to the formation of crystals
Yvon, Stéphane. "Purification de protéines recombinantes du virus de l'hépatite C. Application au diagnostic". Aix-Marseille 3, 1997. http://www.theses.fr/1997AIX30121.
The Hepatitis C virus (HCV), first isolated in 1988, is the causative agent of most parenterally transmitte non-A, non-B hepatitis. Chronic HCV infection affects 1-2 % of the French population, and is a major public healthcare problem. The mode of contamination of HCV is poorly defined, and no vaccine is currently available, making detection of the disease essential. Since no native antigen has been isolated, the development of a screening test for the detection of HCV-specific antibodies present in the sera of infected patients requires recombinant proteins of the virus to be obtained. The structural nucleocapside protein (Core), the E2 envelope protein and the non-structural protein C33 possess numerous antigenic regions. The purpose of this research was therefore to develop purification techniques for these proteins, which are overexpressed in the form of fusion proteins, to integrate these techniques in diagnostic applications (detection of anti-HCV antibodies and antigenemia) and to select the constructions most adapted to HCV diagnosis. Highly glycosylated, the E2 protein is produced in a heterologous eucaryote system (insect cells infected with a recombinant baculovirus), whereas the Core and C33 proteins are overexpressed in Escherichia coli. Different genetic constructions in fusion with a 6-His tag, and including the amino acids 1-48, 1-119, 1-120 and 1-191 of the Core protein (191 amino acids), were purified on chromatographic supports and using electrophoretic techniques. The nucleotide sequence of the C33 protein (272 or 93 amino acids) was expressed in fusion with the glutathione S-transferase or the 6-His tag, and the proteins were purified on affinity supports. A comparative study of proteins GST-C33 (272 aa) and C33-H showed that the histidine system results in both easier purification of the proteins and increased detection sensitivity of the antibodies when using these C33 constructions for diagnostic purposes. The detection senstivity of anti-Core immunoglobulins is optimized with a recombinant protein which uses only the first 119 amino acids of the Core protein
Dion-Poulin, Alexandra. "Étude de la fonctionnalité d’hydrolysats protéiques d’insectes générés par le couplage de l’hydrolyse enzymatique et des hautes pressions hydrostatiques et de l’acceptabilité d’un ingrédient d’insectes auprès de cuisiniers novateurs". Master's thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/68780.
Interest in Entomophagy increases due to several environmental and nutritional benefits, but the social acceptability of this practice is a major obstacle in Western societies. Studies have shown that incorporating insect as an ingredient rather than whole insects promotes consumer acceptability. As a result of their poor functionality, insect meals arecommonly used as a filler agent. Enzymatic hydrolysis is a widely used method to modify and improve the functionality of various proteins, but the effectiveness of this method can be enhanced by using high hydrostatic pressures (HHP) as a pre-treatment. In this project, the functionality of insect meals and protein hydrolysates prepared from meals that were pretreated or not prior enzymatic hydrolysis by pressurization has been determined. The solubility and oil binding capacity were enhanced by this process in contrast to water binding capacity as well as foaming and gelling properties. Viscosity and emulsifying property were slightly increased comparatively to insect meal. However, their different functionalities from those of insect meals could facilitate their acceptability. Specifically, it is acknowledged thata positive consumption experience promotes the entomophagy acceptability especially whenchefs are included in the process. For this project a qualitative study based a priori on Roger’sdiffusion of innovation theory was also conducted to explore the perceptions of innovative chefs on the use of insect ingredients. All participants had a positive opinion of entomophagy and the majority was ready to use it. Understanding these perceptions will increase the use of insect ingredients in the gastronomy and eventually social acceptability.
Guyot-Ferréol, Véronique. "Cristallisation d'enzymes à partir d'extraits protéiques bruts : étude des conditions physico-chimiques de cristallisation, détermination de la solubilité des enzymes majeures et analyse des cristaux". Paris, ENMP, 2002. http://www.theses.fr/2002ENMP1088.
Durand, Rachel. "Valorisation d'hydrolysat de poisson pour la santé humaine : séparation des composés bioactifs par électrodialyse avec membranes d'ultrafiltration et évaluation de leurs activités biologiques impliquées dans le développement du syndrome métabolique". Doctoral thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/66672.
Fish by-product valorization is an economic and environmental issue. For several years, scientific researches have shown that fish by-products contained active molecules for human health, as polyunsaturated fatty acids and peptides. The aim of this thesis was to evaluate the potential use of herring milt hydrolysates for human health, especially by evaluating their potential actions in physiological parameters involved in the metabolic syndrome and the effect of their separation by electrodialysis with ultrafiltration membrane (EDUF) for the production of bioactive fractions. First, we have demonstrated that the supplementation of three different herring milt hydrolysates in a high fat high sucrose diet in mice was able to modulate some physiological functions involved in the metabolic syndrome: improvement of glucose tolerance, increase of the total energy intake and protection against the Lactobacillus disappearance in the gut microbiota. Moreover, the hydrolysates decreased the inflammation induction in macrophages stimulated with LPS at 1ng/ml and 100pg/ml. Secondly, we have evaluated the separation of two herring milt hydrolysates by EDUF: the first one was more complex with a mix of different molecules (lipids, nucleic acids and peptides) while the second one was mainly composed of peptides. A new configuration using four ultrafiltration membranes (two of 50kDa and two of 20kDa) allowed a simultaneous double separation of anionic and cationic compounds. It has been shown that only charged peptides and free amino acids were fractionated in EDUF, while the lipids and nucleic acids didn’t migrate to the recovery fractions. Moreover, the use of membranes with different cut-off allowed a separation of the hydrolysates in different molecular weight ranges. Indeed, the use of 20kDa membranes allowed the concentration of peptides with small molecular weights (<800Da) and free amino acids, while the recovery fractions obtained with the 50kDa membranes were composed oh peptide with higher molecular weights.Thirdly, the potential bioactivities of the recovery fractions and the herring milthydrolysates were evaluated in vitro. Hence, the separation of the first hydrolysate allowed the production of a final fraction increasing the glucose uptake and an antioxidant anionicfraction. While the separation of the second hydrolysate allowed the production of two antiinflammatory cationic fractions as well as the identification of two bioactive peptides sequences. All these results showed that milt herring hydrolysate contained bioactive compounds such as polyunsaturated fatty acids and peptides, improving some physiological functions involved in the MetS and may decrease its occurrence. More over, the separation of the hydrolysates by EDUF allowed the production of bioactive fractions and the identification of two new anti-inflammatory peptide sequences. This work demonstrated the existence of a beneficial effect of herring milt hydrolysate and its fractions for the human health, allowing a better valorization of this by-product of the food industry for the health sector.
Yerima, Hélène Alibada. "Purification et caractérisation des protéines membranaires entérocytaires de liaison de la vitamine B12". Nancy 1, 1995. http://www.theses.fr/1995NAN10436.
Tapparo, Aurélie. "Purification de protéines de liaison du myo-inositol hexakisphosphate chez l'amibe Dictyostelium discoideum". Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10202.
Brouquisse, Renaud. "Etude des protéines fer-soufre des mitochondries végétales : caractérisation et purification de l'aconitase". Grenoble 1, 1987. http://www.theses.fr/1987GRE10088.
Jabrani, Amira. "Régulation de la voie Hedgehog : Étude structurale et fonctionnelle de protéines de signalisation". Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00737495.
Silvestre, Marialice Pinto Coelho. "Nouvelles méthodes d'étude de la composition d'hydrolysats de caséine (cuprimétrie, spectrophotométrie, chromatographie d'exclusion stérique) : application à l'estimation de leur teneur en di- et tripeptides". Paris 11, 1993. http://www.theses.fr/1993PA114820.
Groleau, Paule Émilie. "Étude des interactions peptide-peptide dans un mélange de peptides issu d'un hydrolysat trypsique de ¿-lactoglobuline et de leur influence sur le fractionnement par nanofiltration". Doctoral thesis, Université Laval, 2003. http://hdl.handle.net/20.500.11794/17853.
Whey protein enzymatic hydrolysates contain several functional and bioactive peptides which justify their fractionatation to isolate such interesting molecules. Membrane separation technologies have an excellent potential for peptide separation but peptide-peptide interactions seem to reduce their efficiency. The objectives of this study were to demonstrate the occurrence of peptide-peptide interactions in a tryptic hydrolysate of β-LG, to identify the optimal physico-chemical conditions and peptides responsible of such interactions, as well as to evaluate the influence of such interactions on the fractionation of this hydrolysate by nanofiltration. Isoelectric focusing was used to fractionate the hydrolysate and to demonstrate a peptidic aggregation phenomena at acidic pH. Turbidimetry was then used to highlight the solubility of the hydrolysate according to the pH and some physico-chemical conditions. Peptide aggregates formed at pH 4 were centrifuged and separated, and peptides responsible for this aggregation were identified. From these peptides, the presence of chymotryptic peptides has justified a study of the impact of residual chymotryptic activity in the tryptic preparation on the aggregation phenomena. The second part of this work allowed the evaluation of the effect of these aggregates on the fractionation of the tryptic hydrolysate of β-LG by nanofiltration. It was shown that peptide-peptide interactions do not impair the fractionation. On the contrary, these interactions taking place in the polarized layer may have a positive impact on the fractionation.
Randriamahatody, Zo. "Valorisation biotechnologique des co-produits de crevette : utilisation de la protéolyse enzymatique pour des applications avicoles à Madagascar". Lorient, 2011. http://www.theses.fr/2011LORIS220.
Marine by-products represent valuable biological resources able to generate molecules with biological and nutritional interests. The objective of the present study is to investigate nutritional potentials of hydrolysates from fished and farmed shrimp heads from Madagascar. Thus, 4 enzymes operational at extreme pH conditions were screened: Pepsin, Novozym 37020, Protex 6L and Delvolase. Pepsine was the most efficient enzyme conducing to the production of small-sized peptides with molecular weight inferior to 1 000 Da and the amelioration of amino acids profile, promoting the nutritional quality. Then, peptic hydrolysis was optimized by using different pH conditions and different enzyme inactivations. Introduction of resulting hydrolysates into traditional malagasy poultry feeding ameliorated the production, with weight gains 2,3 times higher. Some hydrolysates presented also growth inhibition activity again fishes pathogenic and food microorganisms. Two hours peptic hydrolysis at maintained pH seemed to be the most efficient condition in the 2 fields studied. It was also the most effective for chitin extraction by producing the poorest mineral and protein containing exoskeleton resides. Those results suggest the efficiency of enzymatic hydrolysis of shrimp heads from Madagascar to ameliorate their nutritional quality, while allowing partially chitin extraction
Farges-Haddani, Bérangère. "Les peptides de colza : une alternative aux protéines animales dans les procédés de culture de cellules de mammifères ?" Vandoeuvre-les-Nancy, INPL, 2005. http://docnum.univ-lorraine.fr/public/INPL_T_2005_FARGES_HADDANI_B.pdf.
In order to improve the performances of animal cell culture processes for the production of therapeutic proteins, and to limit the risks of contamination by animal derived molecules, the effects of a supplementation of serum-free and animal-protein free culture media with rapeseed peptidic fractions were performed. Peptide fractions of various compositions were generated by enzymatic hydrolysis on proteic extract and membrane fractionation. These fractions, rich in nitrogen matter, displayed a variable effect on CHO cells, with a strong cell growth promoting effect of a fraction containing peptides with a broad range of size. In fact, this fraction increased the cell growth, prolonged cell survival, increased the specific production of the recombinant protein, and reduced the whole metabolism of carbohydrates. We also showed that tis peptidic fraction was utilized as nutritioinal additives, but also, as survival and/or growth promoting factors. Other additional advantages ot these peptides were highlighted, such as : an easier adaptation of various cell lines to serum-free conditions, a good cryoprotection of cells during the freezing process au good filterability. Indeed, a very simple culture medium was designed, completely free from animal molecules, and stimulating the growth of adherent or suspension cells from different industrial strains, for various culture scales. These results taken together suggest the use of this new particularly interesting peptidic source as an additive in animal cell culture processes
Tbarka, Noureddine. "Purification et caractérisation de la protéine 90 KD de choc thermique : associée au récepteur des hormones glucocorticoï͏̈des du rat". Lille 1, 1989. http://www.theses.fr/1989LIL10089.
Toillon, Robert-Alain. "Caractérisation des effets apoptotiques des cellules épithéliales mammaires normales sur les cellules cancéreuses du sein". Lille 1, 2001. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2001/50376-2001-229.pdf.
Fargin, Annick. "Le site de liaison des antioestrogènes : solubilisation, caractérisation et recherche d'une méthode de purification". Toulouse 3, 1987. http://www.theses.fr/1987TOU30311.
Rautureau, Gilles. "Expression, purification et étude structurale par RMN de PEBP de drosophile". Orléans, 2006. http://www.theses.fr/2006ORLE2043.
Jan, Gwenaël. "Étude des protéines membranaires acylées de mycoplasma gallisepticum : purification et caractérisation d'antigènes de surface". Rennes 1, 1995. http://www.theses.fr/1995REN10015.
Demers, Mathieu Véronique. "Activité antimicrobienne d'un extrait peptidique issus d'un hydrolysat trypsique de protéines de lactosérum". Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/28671/28671.pdf.
Suwal, Shyam, i Shyam Suwal. "Fractionation of Peptides from Protein Hydrolysate by Electrodialysis with Filtration Membrane : process optimization, Fouling characterization and Control mechanisms". Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26619.
Des peptides bioactifs ont déjà été fractionnés par électrodialyse avec membrane de filtration (ÉDMF) à partir d’hydrolysats de sous-produits de crabe des neiges. L’optimisation des paramètres apparaît maintenant indispensable pour perfectionner le procédé. Ainsi, le taux de migration des peptides, leur sélectivité et l'évolution des paramètres électrodialytiques ont été étudiés pour différents paramètres (configuration, concentration en KCl et types de champ électrique). La configuration (2) de la cellule d’ÉDMF comprenant deux compartiments d'alimentation et un compartiment de récupération a démontré des valeurs de champ électrique local relativement stables par rapport à la configuration (1) constituée d’un compartiment d’alimentation et de deux compartiments de récupération. Des peptides contenant des glutamates, des aspartates, et des glycines ont été séparés avec la configuration 1 et des peptides composés d’arginines et de lysines avec la configuration 2. Un taux de migration peptidique de 13,76 ± 3,64 g/m2h a été obtenu par le maintien constant de la conductivité des solutions. La sélectivité a été accrue en augmentant la concentration en KCl de 1 à 5 g/L dans le compartiment de récupération. Une augmentation de la force ionique a amplifié la charge de surface, agrandissant ainsi la taille effective des pores et réduisant la couche d'hydratation de la membrane d’ultrafiltration. Toutefois, les membranes échangeuses d’anions et de cations ont été colmatées par des peptides et des acides aminés et détériorées pendant l’ÉDMF. Pour résoudre ces problèmes, l’effet de l’application du champ électrique pulsé (PEF) et de l'inversion de polarité (PR) a été étudié. Le taux de migration des peptides n'a pas été affecté sauf avec PR à 40 V. La sélectivité a été maximale avec PEF à 20 V. La dissociation de l'eau a été réduite tout en conservant les propriétés physico-chimiques des membranes grâce à l’application du PEF et de la PR par rapport au courant continu (DC). En outre, la plus faible quantité d'énergie a été consommée avec le PEF. Par conséquent, il a été possible d’optimiser la technologie d’ÉDMF du point de vue de l’efficacité énergétique, de la sélectivité peptidique et de l’encrassement membranaire grâce à l’application du PEF et tout en maintenant la conductivité électrique des solutions.
Bioactive peptides were efficiently separated by using electrodialysis with filtration membrane (EDFM) from snow crab byproduct hydrolysate. Meanwhile, optimization of parameters is indispensable for scaling-up. The peptide migration rate and selectivity as well as evolution of electrodialytic parameters were studied with different parameters such as EDFM cell configuration, KCl concentration and type of electric field. The EDFM stack with two feed and one recovery compartments (configuration 2) has relatively stable electric field strengths (local) than the configuration with one feed and two recovery compartments (configuration 1). Peptides containing anionic amino acids: glutamic and aspartic acid as well as glycine and cationic amino acids: arginine and lysine were fractionated using configuration 1 and 2, respectively. Maintenance of solution conductivity upheld the local electric field and peptide migration throughout the treatment resulting in a higher peptide migration rate of 13.76±3.64 g/m2.h never observed so far. The selectivity of cationic peptides containing arginine and lysine increased significantly with increase in KCl concentration from 1 to 5 g/L. An increase in ionic strength amplified the surface charge density of filtration membrane subsequently increasing effective pore size and reducing hydration layer. However, both anion- and cation-exchange membranes were fouled by peptides and amino acids and were deteriorated during EDFM treatment. To address these problems, the effect of applying pulsed electric field (PEF) and polarity reversal (PR) was studied. The peptide migration rate was unaffected among PEF, PR and DC modes except with PR at 40 V. The selectivity of cationic peptides was maximum with PEF at 20 V. Fouling and water dissociation were significantly reduced and physicochemical properties of IEMs were better-protected with PEF and PR than DC. Moreover, the least amount of energy was consumed with PEF mode. Therefore, the parameters affecting EDFM process were optimized in terms of energy efficiency, selectivity and lower deterioration of membranes by applying PEF regime with configuration 2 and maintaining the constant electrical conductivity of solutions.
Bioactive peptides were efficiently separated by using electrodialysis with filtration membrane (EDFM) from snow crab byproduct hydrolysate. Meanwhile, optimization of parameters is indispensable for scaling-up. The peptide migration rate and selectivity as well as evolution of electrodialytic parameters were studied with different parameters such as EDFM cell configuration, KCl concentration and type of electric field. The EDFM stack with two feed and one recovery compartments (configuration 2) has relatively stable electric field strengths (local) than the configuration with one feed and two recovery compartments (configuration 1). Peptides containing anionic amino acids: glutamic and aspartic acid as well as glycine and cationic amino acids: arginine and lysine were fractionated using configuration 1 and 2, respectively. Maintenance of solution conductivity upheld the local electric field and peptide migration throughout the treatment resulting in a higher peptide migration rate of 13.76±3.64 g/m2.h never observed so far. The selectivity of cationic peptides containing arginine and lysine increased significantly with increase in KCl concentration from 1 to 5 g/L. An increase in ionic strength amplified the surface charge density of filtration membrane subsequently increasing effective pore size and reducing hydration layer. However, both anion- and cation-exchange membranes were fouled by peptides and amino acids and were deteriorated during EDFM treatment. To address these problems, the effect of applying pulsed electric field (PEF) and polarity reversal (PR) was studied. The peptide migration rate was unaffected among PEF, PR and DC modes except with PR at 40 V. The selectivity of cationic peptides was maximum with PEF at 20 V. Fouling and water dissociation were significantly reduced and physicochemical properties of IEMs were better-protected with PEF and PR than DC. Moreover, the least amount of energy was consumed with PEF mode. Therefore, the parameters affecting EDFM process were optimized in terms of energy efficiency, selectivity and lower deterioration of membranes by applying PEF regime with configuration 2 and maintaining the constant electrical conductivity of solutions.
Zhou, Feng-Ling. "Supports à base de silice enrobée par des polysaccharides modifiés : préparation, caractérisation et applications pour la purification de protéines". Paris 13, 1990. http://www.theses.fr/1990PA132027.
Miribel, Laurent. "Purification par chromatographie d'affinité et caractérisation de protéines humaines du plasma : applications méthodologiques, biologiques, génétiques et cliniques". Lyon 1, 1989. http://www.theses.fr/1989LYO1W264.
Pozza, Alexandre. "Surexpression hétérologue et purification du transporteur membranaire ABCG2 : mécanisme d'interaction avec des substrats et des inhibiteurs spécifiques". Lyon 1, 2007. http://www.theses.fr/2007LYO10327.
ABCG2 is an ABC half-transporter involved in multidrug resistance of cancer cells. Our aim is to understand the mechanism of transport and of interaction with specific inhibitors. After some unsuccessful attempts in bacteria, ABCG2 was functionally overexpressed with the insect cells/baculovirus system. The effects of some inhibitors on ATPase activity were studied, as well as the capacity of binding to the purified transporter. This allowed to bring evidence for a different inhibition mechanism for the same inhibitor between the wild-type and R482T mutant of the transporter. The difference in transport-substrate spectrum induced by the mutation is not due to binding, but more likely related to membrane translocation. The recombinant protein appears as two bands, the difference of which is probably of conformational origin
Cerro, Rose-Marie. "Purification de produits d'intérêt biologique par électrophorèse de zone en écoulement continu". Toulouse 3, 1996. http://www.theses.fr/1996TOU30108.
Host, Hélène. "Caractérisation et purification partielle de l'activité méthyltransférase spécifique de la HBHA, adhésine majeure de M. Tuberculosis". Lille 2, 2006. http://www.theses.fr/2006LIL2S060.