Dissertations / Theses: 'Protein-Surfactant'

1

Valstar, Ank. "Protein-surfactant interactions." Doctoral thesis, Uppsala University, Department of Physical Chemistry, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1070.

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Protein-surfactant interactions in aqueous media have been investigated. The globular proteins lysozyme and bovine serum albumin (BSA) served as model proteins. Several ionic and non-ionic surfactants were used.

Fluorescence probe measurements showed that at low sodium dodecyl sulfate (SDS) concentration (< 0.1 M) one micelle-like SDS cluster is bound to lysozyme. From dynamic light scattering (DLS) results it was observed that lysozyme in the complex does not correspond to the fully unfolded protein. At high SDS concentration (> 0.1 M) one compact and one more extended lysozyme-SDS complex coexist.

The influence of surfactant alkyl chain length and headgroup on BSA-surfactant complex formation was investigated. In these studies, binding isotherms were determined by nuclear magnetic resonance (NMR), DLS was used to measure the hydrodynamic radii of the complexes and the size of the micelle-like aggregates on BSA was determined using fluorescence probe methods.

It was observed from fluorescence measurements that the number of bound SDS molecules does not depend on the presence of the disulfide bridges. Reduced proteins wrap more efficiently around the micelle-like structures, resulting in somewhat smaller complexes, as observed with DLS.

Concentrated BSA-SDS solutions and the corresponding heat-set gels were investigated using DLS and fluorescence probe methods. Correlation lengths in the gel were determined and it was concluded that SDS forms micelle-like aggregates on BSA in concentrated solution and gel phase. The gel region in the ternary phase diagram BSA-SDS-3.1 mM NaN₃ has been determined at room temperature.

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2

Cheng, Shu Ian. "Protein separation using surfactant precipitation." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9282.

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Surfactant precipitation applied as a surfactant mediated protein purification technique has considerable potential in protein extraction, and therefore the understanding of the interactions involved and the folding behaviour in the precipitated protein was the first aim of this thesis. The key system parameters such as buffer salt concentration, molar ratio of surfactant to protein and pH which determines the protein stability in protein-surfactant complex formation were evaluated. The surfactant:protein ratio determines saturation of protein binding sites while pH determines the strength of affinity for ionic binding which influences hydrophobic binding with surfactant monomers causing the protein to lose its conformation. The protein-surfactant binding varied for lysozyme, cytochrome c and ribonuclease A with trypsin and α -chymotrypsin, and hence the denaturation profile. In the second aim, protein recovery from surfactant precipitation was enhanced by improving the solvent recovery method and, implementing a new and novel counterionic surfactant recovery method. The effect of a variety of recovery phases and solution conditions on lysozyme recovery was analysed in terms of their ability in maintaining protein stability, recovery yield, and activity. It was found that solvent recovery was limited by solvent polarity and protein solubility, and that the cationic surfactant, trioctylmethylammonium chloride (TOMAC), used to form nonpolar ion pairs with sodium bis-(2-ethylhexyl) sulfosuccinate (AOT) was the most efficient method for recovering protein. The third aim was to assess the influence of protein properties, such as charge and hydrophobicity, on protein separation. The selective extraction of a target protein from mixtures of proteins in both buffer and fermentation broth was investigated. It appears that the optimum surfactant:protein molar ratio for the extraction of the proteins from fermentation broth (lysozyme, cytochrome c and ribonuclease A; 16, 17 and 22 respectively) were similar to those in a buffer system. Lysozyme and ribonuclease A were selectively separated from a binary mixture. The extraction behaviour was well represented by surface charge distribution which is indifferent to system conditions. However, certain broth constituents induced the formation of some unfolded irreversible non-dissolvable precipitate in the recovery process. Finally, the use of non-ionic surfactants, ionic/non-ionic mixed surfactants, and cationic surfactants were investigated in surfactant precipitation system. Non-ionic surfactant does not support direct precipitation of proteins using surfactant or recovery of protein from a protein-surfactant complex, and has no effect in a mixed ionic/non-ionic system. The application of cationic surfactant precipitation to separate trypsin inhibitor was attempted, and good recovery was obtained.

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3

Faizal, Wong Fadzlie Wong. "Protein separation using surfactant precipitation." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/46041.

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Protein precipitation using a variety of surfactants has been shown to have considerable potential as a protein separation technique, and considerable work on using anionic surfactants has been carried out by previous researchers. However, anionic surfactants are only suitable for high pI proteins due to concerns about protein stability. Therefore, the first aim of this work was to develop a surfactant precipitation method for low pI proteins based on using cationic surfactants. The effect of important parameters such as the molar ratio of TOMAC to protein (Rp), and pH on the precipitation of bovine serum albumin, α-amylase, and trypsin inhibitor were examined. Recovery of the TOMAC-protein complex by solvent extraction and counter-ionic surfactant (AOT) was also studied. Varied results were obtained for the three proteins, and were correlated with protein properties, and it was found that the protein’s hydrophobicity and molecular weight were the best predictors for precipitation efficiency and recovery. The second aim of this research was to examine the feasibility of using a biocompatible surfactant – methyl ester sulphonate (MES) as a precipitating-ligand for target proteins in this surfactant precipitation technique. This work was a major breakthrough in the application of a new generation of ‘green’ surfactants for protein extraction. Lysozyme was used as a model protein in a single component system, and the influence of Rp, and pH were examined. Similarly, the recovery of the precipitate using solvent extraction and a counter-ionic surfactant, AOT, was studied. The performance of MES in precipitation was compared to a conventional surfactant, AOT, and it was found that their performance was comparable. This further highlighted its potential to be used as precipitant in protein purification. The third aim of this work was to apply the surfactant precipitation method to the purification of a target protein from a real industrial sample. Bacteriocin produced by Pediococcus acidilactici Kp10 was chosen as a target protein for this purpose. With a concentration of 11.56 mM of AOT (pH 4), precipitate recovery by acetone (0.99 mM NaCl), and a final recovery phase of 20 mM PBS (pH 7), about 86.3% of overall activity recovery, and a purification factor of about 53.8 was obtained. Further, this separation technique was shown to be better than reverse micellar extraction, and aqueous two-phase extraction in terms of performance. Hence, the surfactant precipitation technique was proven to be an effective and a viable separation method.

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4

Gomez, Gil Leticia. "The interaction between cholesterol and surfactant protein-c in lung surfactant." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210205.

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The presence of cholesterol is critical in defining a dynamic lateral structure in pulmonary

surfactant membranes, including the segregation of fluid-ordered and fluid-disordered phases.

However, an excess of cholesterol has been associated with impaired surface activity both in

surfactant models and in surfactant from injured lungs. It has also been reported that surfactant

protein SP-C interacts with cholesterol in lipid/protein interfacial films. In the present study, we

have analyzed the effect of SP-C on the thermodynamic properties of phospholipid membranes

containing cholesterol and on the ability of lipid/protein complexes containing surfactant

proteins and cholesterol to form and re-spread interfacial films capable of producing very low

surface tensions upon repetitive compression-expansion cycling. We have also analyzed the effect of cholesterol on the

structure, orientation and dynamic properties of SP-C embedded in physiologically relevant

model membranes.

Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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5

Wiesener, Annegret. "Proteolytische Degradation von Surfactant Protein D." Diss., lmu, 2002. http://nbn-resolving.de/urn:nbn:de:bvb:19-6462.

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6

Yixiong, Zhang. "Functional protein-polymer surfactant hybrid nanomaterials." Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.680356.

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This thesis presents the investigation of protein-polymer surfactant hybrid nanoconstructs prepared through the surface modification of haemoglobin (Hb) or glucose oxidase (GOx). These discrete stoichiometric conjugates of protein and polymer (with respect to charge) exhibited liquid-like behaviour close to room temperature in absence of solvents. Solvent-free Hb nanoconstructs could be readily dispersed into various organic solvents to form stable molecular protein-polymer surfactant conjugates. Spectroscopic studies showed that surface modification effectively protected the secondary structures of Hb from denaturing under non-aqueous conditions. Importantly, Hb-polymer surfactant conjugates displayed significantly enhanced peroxidase activity in organic solvents compared to their native counterparts, suggesting the polymer surfactant corona successfully shielded the enzyme-bound water layer and increased the protein's functional dynamics for non-aqueous catalysis. Solvent-free GOx nanoconstructs showed unprecedented phase behaviour because of the shape anisotropy of the protein. Below the melting point (40°C), the nanoconstructs exhibited spherulitic mesolamellar structures with an interlayer distance of "'12 nm due to the polyethylene glycol (PEG) chain-chain and alkyl tail-tail interactions within the polymer surfactants of the nanoconjugates. Upon melting, the spherulites transformed into a solvent-free liquid which displayed another PEG-mediated anisotropic phase with dendritic morphology that persisted until the conformation transition temperature (Te) of GOx (58°C). This suggested that the change in intra-polypeptide motions of the protein core during Te significantly influenced the intermolecular interactions of the solvents-free GOx-polymer nanoconjugates. With retained enzymatic activity, GOx-polymer surfactant nanoconjugates were effectively immobilized onto a porous membrane to serve as reusable biocatalysts. The resultant fabricated enzyme-based membrane exhibited greatly improved catalytic efficiency for oxidation of D-glucose. Moreover, incorporation of this enzyme membrane into a glucose-based hydrogel provided a constant release of oxygen (in the form of hydrogen peroxide) over a long period of time, which could offer new opportunities in the development of dressing for wound healing.

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7

Kamalanathan, Ishara Dedunu. "Foam fractionation of surfactant-protein mixtures." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/foam-fractionation-of-surfactantprotein-mixtures(a6484b1a-d796-45ff-bc5c-420ef9130363).html.

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Foam fractionation is an adsorptive bubble separation technology that has shown potential as a replacement to the more costly and non-sustainable traditional downstream processing methods such as solvent extraction and chromatography for biological systems. However biological systems mostly tend to be a mixture of surface active species that complicates the foam fractionation separation. In this thesis a detailed experimental study on the application of foam fractionation to separate a well-defined surfactant-protein mixture was performed with emphasis on the competitive adsorption behaviour and transport processes of surfactant-protein mixtures in a foam fractionation process. Surface tension and nuclear magnetic resonance (NMR) measurements showed that nonionic surfactant Triton X−100 maximum surface pressure, surface affinity and diffusivity were a factor of 2.05, 67.0 and 19.6 respectively greater than that of BSA. Thus Triton X−100 dominated the surface adsorption at an air-water surface by diffusing to the surface and adsorbing at the surface faster than BSA. This competitive adsorption behaviour was observed in foam fractionation experiments performed for Triton X−100/BSA mixtures for different feed concentration ratios and air flow rates. The recovery and enrichment of Triton X−100 were found to increase and decrease respectively with increasing air flow rate for all foam fractionation experiments as expected for a single component system. However the recovery and enrichment of BSA were both found to increase with increasing air flow rate for high feed concentrations of Triton X−100.Bubble size measurements of the foamate produced from foam fractionation experiments showed that at steady state conditions the bubbles rising from the liquid pool were stabilised by BSA. However at the top of the column the recovery of Triton X−100 in the foamate (75% to 100%) was always greater than the recovery of BSA (13% to 76%) for all foam fractionation experiments. In addition, for high feed concentrations of both components and at low air flow rates, the enrichment of BSA remained at almost unity for most experiments and only increased when the recovery of Triton X−100 reached 100%. Thus it was concluded that Triton X-100 displaced the adsorbed BSA from the surface. The foam drainage properties of Triton X−100/BSA mixtures were characterised using two methods; forced foam drainage and from pressure profiles of steady state foam fractionation experiments (pressure method). The drainage data from the forced foam drainage was found not to be compatible with experimental foam fractionation results, by indicating that stable foam was not produced during the foam fractionation experiments. However stable foam was repeatedly produced during foam fractionation experiments. The drainage data from the pressure method was found to be in close agreement to experimental foam fractionation experiments. The work in this thesis takes a significant step beyond the literature experimental foam fractionation studies for multicomponent systems. In addition to investigating the effect of foam fractionation process parameters on the separation of mixed systems, the results from the characterisation studies of surface adsorption and foam properties provided insight and deeper understanding of the competitive adsorption behaviour of surfactants and proteins in a foam fractionation process.

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8

Worthman, Lynn-Ann D. "Surfactant protein A (SP-A) affects pulmonary surfactant morphology and biophysical properties." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0014/MQ34241.pdf.

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9

Schiefelbein, Lars. "Sugar-Based Surfactant for Pharmaceutical Protein Formulations." Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-132870.

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10

Johnson, Conkright Juliana j. "SORTING AND SECRETION OF SURFACTANT PROTEIN C." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin990723467.

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11

Choi, Go Eun (Alex). "The role of surfactant protein d in atherosclerosis." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44734.

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Elevated concentrations of surfactant protein D (SP-D) in the serum have been associated with cardiovascular disease (CVD) mortality. It is not known, however, whether this relationship is causal or an epiphenomenon of lung disease or inflammation. The primary purpose of this thesis was to investigate the effects of SP-D on atherosclerosis. The overarching hypothesis driving this study is that SP-D is pro-atherogenic by modulating plasma lipids and systemic inflammation. These studies will enable development of SP-D as a biomarker of atherosclerosis, ischemic heart disease, and stroke and determine whether SP-D can be a therapeutic target to reduce CVD. To address the hypothesis, SP-D-knockout (KO) mice were crossed with apolipoprotein E (ApoE)-KO mice to produce mice deficient in both SP-D and ApoE. These mice were fed a high fat diet (HFD) for twelve weeks. We then measured the size of atherosclerotic lesions in aorta, determined the lipid profile in the serum, and measured circulating inflammatory cytokines and white blood cell counts in mice. We also challenged SP-D-deficient mice with lipopolysaccharide (LPS), which was microsprayed directly into the trachea. We then determined endothelial function of the descending aorta, 24 hours after the LPS challenge. We found that in the atherosclerotic plaque was significantly smaller in ApoE-KO mice lacking SP-D compared with apoE mice with intact SP-D. Absence of SP-D in the apo-E KO mice resulted in reduced levels of low density lipoprotein (LDL) cholesterol and total cholesterols, and a marked attenuation of certain parameters of systemic inflammation including neutrophil to lymphocyte ratios (NLR) and interleukin (IL)-6 in serum. Deficiency of SP-D was also associated with improved endothelial function following intratracheal LPS challenge. Together, these findings indicate that SP-D plays an active role in modulating lipid profile and systemic inflammation and most importantly may enhance atherosclerosis and thus contribute directly to excess cardiovascular morbidity and mortality.

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12

Desai, Vibhuti H. "Biotechnological applications of a surfactant protein, ranaspumin-2." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/8609/.

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Surfactant activity is generally associated with small molecules rather than biological macromolecules like proteins. Only a few proteins have good intrinsic surfactant activity, an example being the natural surfactant ranaspumin 2 (Rsn2) from the foam nests of the túngara frog. In solution, Rsn2 has a hydrophobic core and hydrophilic exterior, but when Rsn2 comes in contact with an air-water interface, it changes conformation to expose its hydrophobic core to interact with the air and present a hydrophilic face to the water. The unique combination of biocompatibility along with surface activity offers the possibility of developing biomedical applications based on Rsn2. Some of the possible applications, including cell patterning, functionalising scaffolds and stabilising droplets, have been explored in the work described in this thesis. The ability of Rsn2 to coat hydrophobic surfaces persistently, rendering them wettable and the nature of coating and interaction with the surfaces were investigated. This formed the basis for the development of a method to coat a range of hydrophobic polymers, which are commonly used for biomedical applications. These Rsn2 coated surfaces were tested for their capability to control cell adhesion on surfaces which usually do not support cell adhesion. Rsn2 coating was demonstrated to promote, and thus allowed the spatial control over, cell adhesion on otherwise non-cell compatible surfaces. The potential of Rsn2 to be used as a protein fusion partner for the production of further functionalised cell engineering substrates was explored by constructing five different integrin binding sequence (IBS)-Rsn2 conjugates. Specific IBS-Rsn2 proteins proved successful in increasing the adhesion and biomineralising potential of osteoblasts isolated from neonatal rats. In addition, Rsn2's ability to stabilise microscopic oil droplets were investigated. Rsn2 stabilised oil droplets were stable for more than six months. Thus, the surfactant properties of Rsn2 can be used for many potential biomedical applications.

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13

Breitenstein, Daniel. "Strukturelle Organisation des alveolaren Surfactant tensiometrische und oberflächenmassenspektrometrische Untersuchungen zur Lipidspezifität des Surfactant Protein B /." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973036176.

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14

Li, Jing. "Processing, stability and interactions of lung surfactant protein C /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-582-8/.

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15

Ridsdale, Ross Allan. "Studies of myelin basic protein, recombinant upstream binding factor and surfactant protein A." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ31864.pdf.

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16

Meyboom, Astrid. "Untersuchungen zur Wechselwirkung von Surfactant-Protein A mit Liposomen." Doctoral thesis, [S.l.] : [s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=956624294.

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17

Berger, Bryan William. "Protein-surfactant solution thermodynamics applications to integral membrane proteins /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 15.42 Mb., 304 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3200533.

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18

Woskett, Christine Maria. "Competitive adsorption and protein-surfactant interactions in food emulsions." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235613.

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19

Littlejohn, Jamie Reginald. "Structural characterisation of oligosaccharide recognition by surfactant protein D." Thesis, Keele University, 2018. http://eprints.keele.ac.uk/5168/.

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Human surfactant protein D (hSP-D) is a C-type lectin and member of the collectin family that is involved in pathogen recognition as part of the innate immune response. Recognition occurs through the carbohydrate arrays on the surfaces of the pathogens. This work focuses on characterising, at the atomic level, the recognition of oligosaccharide analogues of the carbohydrate arrays using a recombinant fragment of human surfactant protein D (rfhSP-D). The crystal structures of three rfhSP-D complexes with the α(1→6)-linked isomaltotriose, β(1→4)-linked cellotriose and β(1→3)-linked laminaritriose have been successfully solved in P21 using rigid body refinement. Isomaltotriose was refined to 1.96Å with refinement statistics: Rwork 0.1664 and Rfree 0.2084. Cellotriose was refined to 1.59Å with refinement statistics: Rwork 0.0.1879 and Rfree 0.2106. Laminaritriose was refined to 1.75Å with refinement statistics: Rwork 0.1808 and Rfree 0.2193. In combination with two previously solved malto-N-ose complexes, the structures reveal a new binding mechanism for β-D-glucoses in SP-D and identify a new extended binding surface. The crystal structure of rfhSP-D in complex with the disaccharide unit of peptidoglycan, muramyl disaccharide, extracted from the gram-positive bacteria, Micrococcus luteus has been solved in P21 and refined to 1.95Å with final refinement statistics of Rwork 0.1708 and Rfree 0.2169. This crystal structure provides the first insight into recognition of peptidoglycan, an important part of the bacterial cell wall. The rfhSP-D complex with the R7 rough mutant oligosaccharide from S. enterica minnesota has been redetermined from previous work in the group. The structure has been solved in P21 and refined to 1.75Å with final refinement statistics of Rwork 0.1730 and Rfree 0.1960. The crystal structure, along with the known R5 oligosaccharide complex, builds on the understanding of the flexibility and versatility of lipopolysaccharide recognition by hSP-D and the important role of the two flanking residues, Asp325 and Arg343.

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20

Watkinson, Thomas Geoffrey. "Characterising membrane protein-surfactant complexes using mass spectrometry methods." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/16081/.

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Membrane proteins (MPs) facilitate a large number of essential physiological functions and are the targets for greater than 50 % of licensed pharmaceuticals. MPs, however, are difficult to study in vitro as a result of their inherent properties, such as their insolubility in aqueous solution without the presence of a suitable surfactant to maintain the native-like state. For this reason, high resolution structural data of MPs are lacking relative to their water soluble counterparts. This has inspired a need for improvement in methods of solubilisation and analysis of MPs. Amphipols (APols), are a class of novel surfactants for solubilisation of MPs in a native-like state. APols provide a means for solubilisation of MPs with very high kinetic stability using materials and an approach that can be applied, possibly indiscriminately, to any MP. Mass spectrometry (MS) is a multi-faceted technique used in structural biology. Native-MS, which emerged following the development of “soft” ionisation methods such as electrospray ionisation (ESI), has been used extensively to deliver proteins in to the gas phase for analysis of protein ion m/z, whilst maintaining their native state and non-covalent interactions. The combination of native-MS and ion mobility spectrometry (IMS) allows simultaneous measurement of the collision cross section (CCS) and m/z of protein ions. This can be used to study the conformational state of proteins and protein complexes. Native MS is being used more frequently for the study of MPs. Collisional activation of MP:surfactants allows for liberation of MPs and MP complexes, and determination of CCS values using IMS-MS to evaluate the conformational state and investigate the topology and stability of MP complexes. In addition to native-MS, structural proteomics is a growing field for MS-based study of MP structural biology. In work shown here, Fast Photochemical Oxidation of Proteins (FPOP) and Hydrogen-Deuterium Exchange (HDX) coupled to liquid chromatography (LC)-MS allow for observation of solvent accessible regions of the bacterial outer membrane protein (OMP) OmpT in detergent micelles and APols. Work presented here in three experimental chapters shows APols to improve on detergent micelles in the ability to observe the most native-like forms of MPs in the gas phase, finding that the MPs OmpT, Mhp1 and GalP are only observed in the most lowly charged and, hence, more native-like states by nESI-IMS-MS when released from A8-35 and not from DDM micelles. Certain properties of APols (such as molecular weight and charge density) further benefit or hinder delivery of OMPs in to the gas phase. OmpT, tOmpA and PagP are less readily observed by nESI-IMS-MS when solubilised in the largest and most-negatively charged APols. Following from this, FPOP-LC-MS data suggest that this protective effect of APols is mediated through extra contacts with the non-transmembrane regions of MPs, preventing unfolding and protecting MPs from excess charging during ionisation (as evidenced by a decreased degree of oxidation of reactive residue side chains near the boundaries of the transmembrane domain of OmpT). This same degree of protection is not observed using HDX-MS. In fact, data suggests that NAPol (a non-ionic APol with significantly different chemical composition than the previously described A8-35-like APols) promotes greater flexibility of OmpT in the extramembrane regions relative to solubilisation in DDM micelles, despite it being thought to provide the most native-like environment for MPs. Altogether, this thesis shows the power of A8-35-like APols as a solubilisation tool for studying MP structure and function using MS-based techniques. Data shown here also informs on the nature of APol interactions with MPs and how this may manifest in the improved stability of MPs in solution.

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Liefländer, Sarah Kristina. "Geschlechtsspezifische Unterschiede bei der Emphysementwicklung Surfactant Protein-D defizienter Mäuse." Lübeck Zentrale Hochschulbibliothek Lübeck, 2010. http://d-nb.info/1001841387/34.

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Gustafsson, Magnus. "Palmitoylation and amyloid fibril formation of lung surfactant protein C /." Stockholm, 2000. http://diss.kib.ki.se/2000/91-628-4386-9/.

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Thurm, Tobias. "Zellbiologische Charakterisierung von Surfactant Protein C Mutationen bei Interstitiellen Lungenkrankheiten." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-166300.

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24

Kostakis, Thomas. "Bubbles stabilized by nanoparticles and protein, surfactant and particle mixtures." Thesis, University of Leeds, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427781.

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Ocampo, Minette C. "Protein-Lipid Interactions with Pulmonary Surfactant Using Atomic Force Microscopy." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1395050693.

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Kang, W. "Functional studies of SP-D in innate immunity, and its binding protein gp-340 in gastric epithelial development." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249276.

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Makri, Vassiliki. "Das Atemnotsyndrom Frühgeborener Assoziationen zu Polymorphismen des Surfactant-Protein-B-Gens? /." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969500092.

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Regalado, Gonzalez Carlos. "Protein extraction using reverse micelles recovery optimization, purification and mass transfer studies." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262612.

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Cai, Jingfei. "Probing the Membrane Association Mechanisms for Pulmonary Collectins and Mammalian Phospholipase C." Thesis, Boston College, 2013. http://hdl.handle.net/2345/3872.

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Thesis advisor: Mary F. Roberts
Thesis advisor: Eranthie Weerapana
Peripheral proteins from mammals often exhibit multi-domain structures and require metal ions such as calcium as co-factors. This dissertation investigates two types of such proteins -- pulmonary collectins (surfactant proteins A and D) and phosphatidylinositol-specific phospholipase C (PLC) delta1 -- and their interactions with model membranes. One approach to work around the complexity brought upon by such multi-domain protein structure is to use a truncated construct or an isolated single domain. For pulmonary collectins, homotrimers consisting of the neck domain and the carbohydrate recognition domain were used in a novel NMR assay for better understanding of their lipid-specific interactions with the membranes. For PLC delta1, we were particularly interested in the role of the EF-hand domain. The isolated EF-hand domain of PLC delta1 was first used to characterize its interactions with membranes and identify key residues responsible for such interactions. These key residues in the N terminal lobe of the EF-hand domain, either cationic or hydrophobic, were then found to affect the hydrolysis activity of the full-length enzyme. A common role for this region of the PLC in facilitating proper membrane association was thus proposed
Thesis (PhD) — Boston College, 2013
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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30

Delestrain, Céline. "Mécanismes physiopathologiques des mutations du gène codant la protéine C du surfactant dans le développement des pneumopathies interstitielles de l'enfant." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC0056.

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Les mutations du gène codant pour la protéine C (SP-C) du surfactant pulmonaire (SFTPC) sont à l’origine de pathologies interstitielles chroniques du nourrisson, de l’enfant mais également de l’adulte. Une importante hétérogénéité phénotypique est cependant observée, y compris au sein d’une même famille. Par un épissage alternatif, le gène SFTPC permet la synthèse de deux isoformes du précurseur protéique de SP-C (proSP-C) pour aboutir à la protéine mature après plusieurs modifications post-traductionnelles. Les conséquences des mutations de SFTPC sur l'homéostasie du surfactant ne sont pas clairement élucidées, mais il semble que le mauvais repliement de la protéine soit une caractéristique commune. A l’issue de nos travaux antérieurs, nous avons mis en évidence un effet de certaines mutations et de polymorphismes sur l’épissage de SFTPC faisant ainsi varier significativement l’expression de chacune des deux isoformes protéiques, sans qu’à l’heure actuelle nous ne connaissions le rôle de chacune dans la synthèse de la protéine SP-C mature. Notre projet, s’inscrivant dans la continuité de mon master 2, a pour but de mieux comprendre les mécanismes physiopathologiques pré et post-transcriptionnels associés aux variations de SFTPC et leurs conséquences sur le développement des pneumopathies interstitielles. Le premier axe de notre projet repose sur l’étude in vitro (lignées cellulaires) et in vivo (modèle murin, ARN des patients) des variations de chacun des isoformes. Dans un second axe, nous souhaitons poursuivre l'étude de facteurs pouvant influencer le phénotype des patients porteurs de mutations du gène SFTPC, qu'ils soient d'origine externes (infections virales et bactériennes ou environnementaux comme le tabac) ou génétique. Collectivement, ces études nous permettrons de fournir une signature moléculaire pour cette maladie et d’identifier de nouvelles cibles thérapeutiques afin d’en améliorer le pronostic mais également la prise en charge et la qualité de vie des patients
Surfactant pathologies linked to mutations in the SFTPC gene, via autosomal dominant transmission, are most commonly associated with diffuse interstitial diseases in infants, children and adults, and may also be responsible for acute respiratory distress syndrome in newborns. They are most often accompanied by a high morbidity and mortality rate, thus rendering early diagnosis essential for ideal intervention and support. Mutations in the SFTPC gene lead to alveolar and intracellular accumulation of an abnormal form of the precursor protein SP-C (ProSP-C), which is responsible for the resulting tissue damage. However, the pathophysiological mechanisms are not yet completely deciphered. The gene encodes two isoforms of ProSP-C from three alternative transcripts. The expression level of each is currently unknown and the vast majority of studies evaluating the effect of mutations are performed on only one isoform. Incidentally, our preliminary results on the analysis of RNA extracted from bronchoalveolar washing, both from control subjects and patients harboring a mutation, show that the all three SFTPC transcripts are expressed and that the presence of a mutation is associated with a variation in the expression levels of the transcripts. The aim of my project is to study the expression level of SFTPC transcripts and ProSP-C isoforms from the heterologous expression of the SFTPC gene (exons and introns) in cell lines. I will beanalyzing the post-translational maturation profile of these pro-proteins and evaluating the effect of the mutations on their expression and maturation in both our cellular models and in vivo with two Knock-in mice models.A better understanding of the pathophysiology of genetic abnormalities associated with mutations in the SFTPC gene will not only greatly contribute to earlier management of patients, but also it will help in modifying the progression of lung injury and its prognosis

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Ahmed, Abdul Salim. "Structural studies of the interaction of bacterial lipopolysaccharides with C-reactive protein and lung surfactant protein D." Thesis, Keele University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572426.

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In this thesis, recognition of the complex natural ligand lipopolysaccharide (LPS) by the innate immune proteins C-reactive protein (CRP) from Limulus polyphemus (Atlantic horseshoe crab), and human surfactant protein D, in the form of a recombinant fragment comprising the a-helical coiled-coil neck plus three lectin domains (CRD), has been studied using X-ray crystallography. The intact LPS from three bacteria, E. coli (0111.B4), P. aeruginosa (serotype 10) and H influenzae type b strain RM153 Eagan (wild type and 4A mutant), were subjected to mild acid hydrolysis to separate the lipid A from the extended oligosaccharide fraction (OS) to improve solubility in crystallisation studies. X-ray diffraction data collection using synchrotron radiation on crystals of Limulus CRP grown in the presence of intact E. coli LPS provided diffraction to 2.oA resolution showing a large unit cell with multiple copies of the molecular aggregate of unknown size in the asymmetric unit. Structure solution was not attempted but has since been achieved by other members of the research group although significant difficulties remain with the refinement. Crystallographic analysis at 1.7 A resolution of the recombinant fragment of human SP-D crystals with H influenzae Eagan wild type and Eagan 4A OS shows no binding of the Eagan wild type OS, however, the Eagan 4A OS ligand is found complexed to the protein . CRD in chains Band C in a calcium dependent manner. No ligand binding could be observed in chain A. In both chains the binding is found in one orientation involving the core L,D-heptose C6- and Cr hydroxyl groups of the glycerol side chain, despite the availability of a terminal core glucose bearing vicinal equatorial C3 and C4 hydroxyl groups. Interaction with Kdo, seen in a putative anyhydro closed 5-membered ring form, is also evident suggesting that efficient recognition requires multiple binding interactions.

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Rova, M. (Meri). "The significance of surfactant protein gene polymorphisms in multifactorial infantile pulmonary diseases." Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:9514277481.

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Abstract Pulmonary surfactant is a lipid-protein mixture that lines the inner surface of the lung. The main function of surfactant is to reduce surface tension at the air-liquid interface, thus preventing alveolar collapse at the end of expiration. Lack of surfactant is the main cause of respiratory distress syndrome (RDS) in preterm infants. Very preterm babies are at risk of developing a lung disease called bronchopulmonary dysplasia (BPD). The surfactant proteins SP-A, -B, -C and -D have important functions in surfactant structure, homeostasis and innate immunity of the lung. The genes of these proteins have been studied as candidates for several multifactorial lung diseases both in adults and in children. The aim of the present study was to examine the genetic variation in SP genes and to evaluate the role of SP gene polymorphism in the etiology of severe pulmonary infantile diseases, including RDS, BPD and severe respiratory syncytial virus (RSV) infection among the Finnish population. Conventional allelic association methods in combination with multiparameter analysis and family-based transmission disequilibrium test (TDT) were used. The SP-D Met11 allele was associated with a risk for severe RSV bronchiolitis in a matched case-control setting of 84 infants with severe RSV infection and 93 control infants. The variants of the SP-C gene had no detectable association with BPD. However, a modest association of SP-C Asn138 and Asn186 alleles with RDS was found. A length variation in the SP-B gene was associated with BPD among very preterm infants born before 32 weeks of gestation. The SP-B intron 4 deletion variant allele increased the risk for BPD especially in very low birth weight infants. The association was confounded by birth order, being evident only among presenting infants, who are more prone to ascending infections during a preterm birth process. The present study provides new evidence about the significance of SP gene polymorphisms in the etiology of complex infantile pulmonary diseases, including RDS, BPD and severe RSV bronchiolitis. The results help us to understand the molecular mechanisms underlying these diseases and may, in the long run, enable better treatment of these life-threatening diseases
Tiivistelmä Keuhkosurfaktantti on keuhkon sisäpintaa peittävä kalvomainen rasva-proteiinikompleksi, jonka tärkein ominaisuus on pintajännityksen vähentäminen keuhkorakkuloissa. Surfaktantin puutos ennenaikaisesti syntyneillä lapsilla aiheuttaa hengitysvaikeusoireyhtymän, RDS-taudin (respiratory distress syndrome). Alle 30 raskausviikon iässä syntyneistä, useimmiten RDS-taudin saaneista keskosista n. 30 % sairastuu vakavaan krooniseen keuhkotautiin, BPD-tautiin (bronchopulmonary dysplasia). Surfaktanttiproteiineilla SP-A, -B, -C ja -D on osoitettu olevan tärkeä tehtävä surfaktantin toiminnassa ja keuhkon synnynnäisessä immuniteetissa. Tämän tutkimuksen tavoitteena oli selvittää surfaktanttiproteiineissa esiintyvän geneettisen muuntelun määrää ja merkitystä keskosten RDS- ja BPD-taudeissa sekä pienten lasten vakavassa respiratory syncytial -viruksen (RSV) aiheuttamassa keuhkotulehduksessa. Tutkimuksen laajin osa keskittyi tutkimaan keskosten BPD-tautia ja surfaktanttiproteiinien geenien osuutta siinä. Geneettisen muuntelun merkitystä tarkasteltiin populaatiogeneettisin keinoin tapaus-verrokkiasetelmissa ja perheaineistojen avulla. Yhteensä analysoitiin noin tuhannen lapsen ja yli kahdensadan vanhemman DNA-näytteet. Tutkimuksessa havaittiin SP-D-geenissä olevan metioniini11-geenimuodon liittyvän pienten lasten vakavaan RSV-infektioon. Lisäksi saatiin uutta tietoa SP-C-geenin populaatiotason yleisestä muuntelusta ja todettiin SP-C:n asparagiini138 ja asparagiini186 -geenimuotojen yhteys keskosten RDS-taudin esiintymiseen. Merkittävin löydös oli SP-B-geenissä olevan deleetiovariantin kytkeytyminen alle 32-viikkoisina syntyneiden keskosten BPD-tautiin. Geneettisen altistuksen lisäksi BPD-tautiin sairastumiseen vaikuttivat lukuisat keskosuudelle ominaiset seikat, kuten alhainen syntymäpaino, RDS-tauti ja syntymähetkellä todettu hapenpuute. Geneettisen tekijän vaikutus oli voimakkain erittäin pienipainoisilla keskosilla. Tutkimuksen tulokset ovat tuoneet arvokasta lisätietoa surfaktanttiproteiinien geenien osuudesta keskosten RDS- ja BPD-taudeissa sekä pienten lasten vakavassa RSV-infektiossa. Ne auttavat ymmärtämään näiden molekyylibiologisia syntymekanismeja ja voivat ajan mittaan olla edistämässä uusien hoitomuotojen kehittämistä

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Islam, Mohammad R. "Catanionic surfactant vesicles as a platform for probing protein-carbohydrate multivalent interactions." Thesis, Wichita State University, 2011. http://hdl.handle.net/10057/5044.

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This thesis describes the work on understanding the phase behavior of mixed surfactant systems and on the surface-functionalization and modification of catanionic vesicles with an aim toward probing protein-carbohydrate multivalent interactions. To understand the phase behavior of aqueous mixture of cetyltrimethylammonium tosylate (CTAT) and sodium dodecylbenzenesulfonate (SDBS) solutions at micromolar surfactant concentrations, calculations were performed in conjunction with fluorescence correlation spectroscopy (FCS) studies to probe the composition and size of aggregates formed at low concentration. Toward this end, the critical micelle concentration (cmc) of CTAT was measured to be 0.12-0.35 mM and cmc of SDBS to be 2.2-2.8 mM, both values agree with literature values. The critical aggregation concentration (cac) for the mixtures of CTAT and SDBS having a 1.8-fold molar excess of CTAT was measured to be 2.6 μM. Using these measured values, for CTAT-rich mixtures, the mole fraction of CTA+ in the vesicle bilayer is calculated to be 0.56 at the cac. The interaction parameter is calculated to be -24. These calculations in this thesis suggest that the surface charge at low surfactant concentration near the cac. This theoretical prediction was supported by FCS studies of DNA and CTAT-rich vesicles binding near the cac. Next the catanionic vesicle outer membrane was functionalized by hydrophobic insertion of hydrocarbon chain of the glycoconjugate n-dodecyl-β-D-glucopyranoside (C12-Glu). Kinetics of multivalent interactions between the lectin concanavalin A and C12-Glu was studied by cryo-TEM and stopped-flow turbidometry. Inhibition multivalent binding studies were conducted and a potential new tool has been developed in evaluating multivalent inhibition.
Thesis (M.S.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry

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Marri, Eswari. "Immune surveillance of activated immune and tumour cells by surfactant protein D." Thesis, Brunel University, 2015. http://bura.brunel.ac.uk/handle/2438/13847.

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Surfactant protein D (SP-D) is a carbohydrate/charged pattern recognition molecule of the innate immune system. By virtue of its ability to recognize an array of carbohydrate patterns on the surface of a range of pathogens, SP-D can bring about opsonisation, enhanced phagocytosis and killing of a diverse range of viruses, bacteria and fungi. In addition to antimicrobial functions, which also includes bacteriostatic and fungistatic properties SP-D has also been shown to bind allergens derived from a number of sources including house dust mite, Aspergilllus fumigatus and pollen grains. SP-D allergen interaction leads to inhibition of specific IgE binding and subsequent downregulation of histamine release from sensitized basophils and mast cells. Thus, a number of murine models of pulmonary hypersensitivity and allergic asthma induced by ovalbumin, house dust mite and Aspergillus fumigatus allergens/antigens have been tested for the ability of SP-D to dampen allergic symptoms on the immunological parameters. In general, treatment of allergic models with a recombinant fragment of human SP-D (rh SP-D; composed of trimeric, neck and carbohydrate recognition domain) has been shown to cause downregualtion of specific IgE synthesis, pulmonary and peripheral eosinophilia and airway hyper reactivity, and Th2→Th1 polarisation. However, therapeutic alleviation of eosinophilia by rh SP-D treatment became evident when SP-D gene deficient mice were found to be hypereosinophilic In fact, rhSP-D binds well to eosinophils derived from allergic patients and induces apoptosis without affecting eosinophils derived from healthy individuals or non-activated/non-sensitized eosinophils. Proteomic analysis of rh SP-D treated eosinophillic cell line that revealed that apoptosis induction takes place via p53 pathway. In this thesis, proteomic signatures were replicated using a leukemic cell line AML14.3D10 via qPCR analysis by identifying targets from a spectrum of genes, which were either upregulated or downregulated. It appears that in spite of induction of apoptosis by rh SP-D, different cells respond differentially at molecular levels (Chapter 3). Sensing that SP-D can induce apoptosis in altered or transformed cells; the effect of SP-D gene expression within pancreatic cancer cells was also investigated. The experiments confirmed p53 pathway dependence for suppression of cancer. Interestingly, factors responsible for metastasis for cancer are also downregulated by endogenous overexpression of SP-D, as validated by wound healing assay. We conclude that SP-D is a general immunosurveillance molecule, which is involved in the clearance of altered and transformed cells (Chapter 4). Chapter 5 shows a direct interaction between DC-SIGN and rh SP-D that inhibits DC-SIGN interaction of allergens and HIV-1, tow common ligands for SP-D and DC-SIGN. Using transfected human embryonic kidney (HEK) cells expressing surface DC-SIGN, we found that pre-treatment of these cells with rhSP-D suppressed DC-SIGN mediated transmission of HIV-1to co-cultured PBMCs. The effect of rhSP-D-DC-SIGN In conclusion, this thesis highlights a broader immune role of SP-D in homeostasis and probably assigns potential functions of extrapulmonary and/or locally synthesized SP-D within non-lung tissues and blood.

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da, Silva Ruben Filipe. "Structural studies of surfactant protein D in complex with bacterial lipopolysaccharide ligands." Thesis, Keele University, 2017. http://eprints.keele.ac.uk/4177/.

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This work is focused on the recognition of natural lipopolysaccharide (LPS) by the innate immune protein human lung surfactant protein D (hSP-D) in the form of a biologically active recombinant fragment (rfhSP-D), containing the α-helical coiled-coil and three carbohydrate recognition domains (CRD). Intact LPS from two bacterial strains, S. minnesota (R5 mutant) and H. influenzae type b Eagan (CA7 mutant), were delipidated by means of mild acid hydrolysis, leaving the purified polysaccharide (PS) to be used in X-ray diffraction studies by means of co-crystallisation with rfhSP-D. S. minnesota R7 full LPS was also investigated following development of a suitable solubilisation method which also utilised the LPS from E. coli O111:B4. The structural studies of rfhSP-D bound to H. influenzae Eagan CA7 PS (solved and refined at 2.98 Å) and to S. minnesota rough mutant LPS/PS (solved and refined at 3.3 Å) reveal that rfhSP-D binds to LPS preferentially through the non-terminal inner core heptose HepI via the O6’ and O7’ hydroxyls. rfhSP-D recognition of S. minnesota HepI shows a similar bound heptose orientation to that previously reported for heptose binding by rfhSP-D in the literature with an indication of normal Kdo in the inner core Kdo-Hep-Hep trisaccharide. rfhSP-D recognition of the HepI of H. influenzae Eagan CA7 reveals a novel bound heptose orientation, with the heptose rotated by 180° about C5-C6, resulting in the O6’ and O7’ hydroxyls being interchanged with respect to coordination to Ca1 and protein. The novel orientation of HepI is accompanied by a salt bridge being formed between the flanking residue Arg343 and Glu347, both of which adopt a previously unseen conformation. The novel binding mechanism of rfhSP-D for Eagan CA7 suggests flexibility in recognition and offers evidence to explain why this mutant binds more weakly than the Eagan 4A mutant to both rfhSP-D and hSP-D.

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Jounblat, Rania Ahmad. "Complement and surfactant protein D in the innate immunity to Streptococcus pneumoniae." Thesis, University of Leicester, 2003. http://hdl.handle.net/2381/29841.

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The aim of this project was to investigate the role of complement and lung surfactant protein D in innate immunity to S. pneumoniae.;Pneumolysin, a cytolytic toxin produced by S. pneumoniae, is able to activate the classical complement pathway. The deletion of the ability of pneumolysin to activate complement affected the early growth of pneumococcus in the lungs, the onset of bacteraemia, the histological changes and the recruitment of T lymphocytes into lung tissue during bronchopneumonia.;Lung complement C3 was substantially activated after intranasal infection with wild-type S. pneumoniae in comparison with the isogenic mutant strain unable to produce pneumolysin (PLN-A).;Data presented in this thesis showed that the classical complement pathway plays a critical role in the innate immunity to S. pneumoniae infection. Deficiency in C1q increased the susceptibility to pneumococcal infection and was associated with defects in pneumococcal clearance from lungs and blood, less severe histological changes, recruitment of T cells and a substantial decrease in the activation of complement C3 in the lung.;In vitro studies showed that lung surfactant protein D or its receptor gp-340 is able to bind and agglutinate several strains of S. pneumoniae. Sp-D did not enhance the uptake of pneumococcus by neutrophils. The capsule-type is not a determinant for S. pneumoniae aggregation by Sp-D or gp-340.;Sp-D-deficient mice showed increased susceptibility to pneumococcal infection. Deficiency in Sp-D was associated with decreased pneumococcal clearance in lungs and trachea, early onset and increased levels of bacteraemia. In the infected lung, accumulation of T lymphocytes and more severe inflammation were observed in the absence of Sp-D.

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Ryan, Marnie A. "The Role of Membrane Remodeling in Surfactant Protein B (SP-B) Function." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1127263783.

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Schiefelbein, Lars [Verfasser], and Wolfgang [Akademischer Betreuer] Frieß. "Sugar-Based Surfactant for Pharmaceutical Protein Formulations / Lars Schiefelbein. Betreuer: Wolfgang Frieß." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2011. http://d-nb.info/1016172737/34.

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39

Smallcombe, Caroline. "Structural studies of the recognition of bacterial lipopolysaccharides by human surfactant protein-D." Thesis, Keele University, 2016. http://eprints.keele.ac.uk/3263/.

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SP-D is a large hydrophilic protein, consisting of four collagenous trimers, which is secreted by alveolar type II and non-ciliated bronchiolar epithelial cells and participates in calcium-dependant agglutination of inhaled microorganisms. Known high-resolution crystal structures of mono- and disaccharide bound recombinant human SP-D include a heptose disaccharide that mimics the inner core fragment of bacterial lipopolysaccharide. This thesis focuses on the structural characterisation of SP-D binding to lipopolysaccharides from Gram-negative bacteria. Intact LPS and several hydrolysed smooth and rough mutants were soaked into native crystals of a recombinant head and neck fragment of SP-D. Those soaked with hydrolysed Escherichia coli J5 and Salmonella minnesota R7 LPS showed electron density corresponding to ligand in the ligand-binding site. All crystals processed conformed to spacegroup P21, all with unit cells close to a= 55, b= 108, c= 55 Å, = 91°. The maximum resolution diffraction observed was 1.63 Å. The R7-soaked structure was refined at 1.77 Å, with a final R-factor of 18.71% and R-free of 22.05%. The structure reveals a well-defined trisaccharide unit of two heptose saccharides and a single Kdo residue in protein chains B and C. The Kdo is present as a five-membered, anhydro residue known to form during mild acid hydrolysis. The third, outermost heptose of the R7 inner core is not visible in the electron density. The refined structure demonstrates binding of LPS via the O6 and O7 hydroxyl groups of the glycerol sidechain of HepI, the innermost heptose, demonstrating for the first time structurally not only the binding of a physiologically relevant bacterially derived ligand but also the recognition of a non-terminal monosaccharides by SP-D. No direct interaction is observed between the second heptose and the protein, but two hydrogen bonds are seen between the anhydro-Kdo and the amino acids Arg343 and Asp325 which flank the SP-D ligand binding pocket.

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Liefländer, Sarah Kristina [Verfasser]. "Geschlechtsspezifische Unterschiede bei der Emphysementwicklung Surfactant Protein-D defizienter Mäuse / Sarah Kristina Liefländer." Lübeck : Zentrale Hochschulbibliothek Lübeck, 2010. http://d-nb.info/1001841387/34.

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Barnett, Catherine Margaret Eleanor. "Association of Single Nucleotide Polymorphisms in Surfactant Protein A and D with Otitis Media." The University of Waikato, 2007. http://hdl.handle.net/10289/2338.

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Otitis Media is one of the most common childhood diseases. Recurrent acute otitis media RAOM is characterized by repeated episodes of inflammation of the middle ear in conjunction with middle ear fluid, and often with an inflamed or bulging eardrum. Defective clearance by the Eustachian tube results in mucus build-up and is characteristic of otitis media with effusion (OME). Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, respiratory syncytial virus, and rhinovirus are the most common contributors to otitis media pathogenesis. In New Zealand, OME has been implicated with conductive hearing loss in childhood and has been shown to significantly impact on speech and language development. New Zealand Māori and Polynesian children have displayed significantly higher hearing test failure rates than European-Caucasian children. The collectins, Surfactant Protein (SP)-A and -D are encoded by three genes (SP-A1, SP-A2, and SP-D) and are host defense proteins present in the middle ear and Eustachian tube. Single nucleotide polymorphisms (SNPs) in SP-A1 and SP-A2 have been associated with increased or decreased susceptibility to otitis media, meningococcal disease, and range of respiratory diseases. Using allele-specific primers and real-time PCR with SYBR Green I melting curve analysis, four groups of individuals were genotyped for eleven SP-A1, SP-A2, and SP-D SNPs: European-Caucasian individuals with RAOM/OME; New Zealand Māori/Polynesian individuals with RAOM/OME; individuals with meningococcal disease; and a control group. The computer program, Haploview, was employed to perform χ2 analyses and identify statistically significant associations of alleles/haplotypes with RAOM/OME or meningococcal disease. In the European-Caucasian population, two SP-A1 alleles, one SP-A2 allele, and four haplotypes (CGAGC, 1A3, 1A9, and 1A10) were found to be associated with increased risk of RAOM/OME (P lt; 0.05). Conversely, haplotypes 6A2 and 1A2 were found to be protective against susceptibility to RAOM/OME (P lt; 0.05). In New Zealand Māori and Polynesian individuals, two SP-A1 alleles, three SP-A2 alleles, one SP-D allele, and four haplotypes (6A8, 6A10, 1A3, and 1A10) were found to be associated with increased risk of RAOM/OME (P lt; 0.05). An additional four haplotypes (6A2, 1A0, 1A2, and TA) were determined to be protective against susceptibility to RAOM/OME (P lt; 0.05). However, protective SPA1/SPA2/SPD haplotype 6A2-1A0-TA was significantly under-represented in the New Zealand Māori and Polynesian population (P lt; 0.05). A single allele and haplotype were associated with increased risk of meningococcal disease (P lt; 0.05). The findings of this study confirm that specific genetic variants of SP-A and SP-D are associated with either increased or decreased risk of developing RAOM and/or OME. Furthermore, it was demonstrated that New Zealand Māori and Polynesian individuals appear to exhibit more haplotypes susceptible to RAOM/OME. This may provide a partial explanation for the higher RAOM/OME-related failure rates of hearing tests in New Zealand Māori and Polynesian children. However, there are numerous socio-economic and environmental factors that also contribute to otitis media pathogenesis which were not considered in this study. The effects of the SP-A1, SP-A2, and SP-D alleles and haplotypes on the bacterial/viral binding efficiencies of SP-A and SP-D need to be investigated by further research, using a large population, to confirm the association with susceptibility or resistance with RAOM/OME.

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Siauw, Christina L. Y. "Rabbit surfactant-associated protein A and the effects of glucocorticoids in developing rabbit lung." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq24913.pdf.

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43

Henning, Lisa Novik. "Pulmonary surfactant protein a regulation of macrophage toll-like receptor expression, activity, and trafficking /." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1211479279.

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He, Xuefei. "Pathophysiological study of the effects of plasmalogen deficiency on ATII cell surfactant protein secretion." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110507.

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Past studies suggest that the primary cause of death in patients with the peroxisome disease, rhizomelic chondrodysplasia punctata (RCDP), may be due to lung dysfunction. In our laboratory, we have evaluated the RCDP equivalent mouse model, the Pex7 hypomorphic mouse, and found that it shows abnormal lung morphology, which coincides with the cause of death. However, the pathophysiology of this pulmonary dysfunction still remains unknown. RCDP is an autosomal recessive disease that involves PEX7 gene mutations. The PEX7 gene encodes a transporter protein that is essential for plasmalogen synthesis, and plasmalogens in turn, may play an integral role in secretion of surfactant proteins and lipids in specialized pulmonary cells e.g. alveolar type II (ATII) cells. We hypothesize that the hypomorphic Pex7 mouse model will secrete distinctively different quantities of surfactant proteins compared to wild type. To test this hypothesis, we stimulated ATII cell secretion under three-hour treatments using three drugs: terbutaline, ionomycin and TPA (tetra-12-O-tetradecanoylphorbol 13-acetate). These stimulate the PKA-dependent, CaMK-dependent and PKC-dependent pathways, respectively, of surfactant protein secretion. Surfactant protein B secretion was quantified by an immunoblotting assay.Our results show that the response of ATII cells to these drugs may be strain-dependent and age-dependent. ATII cells from wild type adult C57Bl6 (pure background) responded to terbutaline stimulation with increased surfactant protein B secretion; whereas ATII cells from wild type adult C57Bl6/129 (mixed background) did not. Furthermore, ATII cells from wild type neonatal C57Bl6/129 can only respond to terbutaline stimulation at ten times the concentration used on adult ATII cells.Finally, ATII cells from the Pex7 deficient mice (C57Bl6/129) did not respond to terbutaline stimulation from both neonatal and adult mice. We conclude that plasmalogen deficiency in the Pex7 hypomorphic model (C57Bl6/129) may be associated with inefficient PKA signaling in the neonatal mice since it fails to respond to terbutaline stimulations compared to control.
Des études antérieures suggèrent que la principale cause de décès chez les patients atteints de la maladie des peroxysomes, chondrodysplasie ponctuée rhizomélique (RCDP), peut être due à un dysfonctionnement pulmonaire. Dans notre laboratoire, nous avons évalué le modèle de souris RCDP équivalent, la souris PEX7 hypomorphic, et j'ai trouvé qu'il montre la morphologie anormale des poumons, qui coïncide avec la cause du décès. Cependant, la physiopathologie de ce dysfonctionnement pulmonaire reste encore inconnue.RCDP est une maladie autosomique récessive qui implique PEX7 mutations du gène. Le gène code pour une protéine PEX7 transporteur qui est essentiel pour la synthèse plasmalogène, et plasmalogènes à son tour, peut jouer un rôle essentiel dans la sécrétion de protéines du surfactant et des lipides dans les cellules pulmonaires spécialisés ex. alvéolaires de type II (ATII) cellules. Nous émettons l'hypothèse que le modèle de souris hypomorphic Pex7 va sécréter des quantités nettement différents de protéines du surfactant par rapport au type sauvage. Pour tester cette hypothèse, nous avons stimulé la sécrétion cellulaire ATII sous trois heures de traitements en utilisant trois médicaments: la terbutaline, ionomycine et TPA (tétra-12-O-tétradécanoylphorbol 13-acétate). Ces stimuler les PKA-dépendantes, des voies CaMK-charge et de la PKC-dépendante, respectivement, de la sécrétion de protéine tensioactif. La sécrétion de la protéine B du surfactant a été quantifiée par un dosage immuno-empreinte.Nos résultats montrent que la réponse des cellules Atii à ces médicaments peut être souche-dépendante et âge-dépendante. Cellules adultes ATII de type sauvage C57BL6 (fond pur) a répondu à la terbutaline stimulation avec la sécrétion de surfactant B accru en protéines, tandis que les cellules de Atii sauvage adulte de type C57Bl6/129 (origine mixte) n'a pas fait. En outre, les cellules de type sauvage Atii néonatale C57Bl6/129 ne peut répondre à la terbutaline stimulation à dix fois la concentration utilisée sur des cellules adultes ATII.Enfin, les cellules ATII des Pex7 souris déficientes (C57Bl6/129) n'ont pas répondu à la terbutaline la stimulation des deux souriceaux nouveau-nés et les adultes. Nous concluons que carence en plasmalogène dans le modèle Pex7 hypomorphic (C57Bl6/129) peut être associé à inefficaces PKA de signalisation dans les souriceaux nouveau-nés, car il ne parvient pas à répondre à des stimulations terbutaline par rapport à contrôler.

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45

Carlson, Tracy Karin. "The Effects of Pulmonary Surfactant Protein-D on Innate Immune Cells and Tuberculosis Pathogenesis." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299708141.

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46

Celik, Hakan. "Time and Temperature Dependent Surface Tension Measurements of Responsive Protein-based Polymer Surfactant Solutions." Cleveland State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=csu1440182119.

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47

VENDITTO, CARMEN. "TRANSCRIPTIONAL SIGNATURES DURING THE DEVELOPMENT OF METAL-INDUCED ACUTE LUNG INJURY: ROLE OF SURFACTANT PROTEIN B." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1147987059.

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48

Lim, Boon-Leong. "Cloning and expression of a C1q-binding protein and two of the collections (Collectin-43 and lung surfactant protein D)." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239328.

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49

Essö, Carola. "Modifying Polydimethylsiloxane (PDMS) surfaces." Thesis, Mälardalen University, Department of Biology and Chemical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-491.

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Abstract:

The aim of the project was to modify polydimethylsiloxane (PDMS) surfaces in order to minimize adsorption of proteins. PDMS is used in micro-fluidic devices that control the delivery of samples to a sensor chip in Biacore instrumentation. These instruments are used to characterize interactions between biomolecules with a detection principle based on surface plasmon resonance (SPR). To minimize adsorption of proteins poly-ethylene-oxide (PEO) based surfactants, were added to the buffer. The added PEO surfactants were P20, Pluronic F-127 and Brij 35. Interaction of these surfactants with the sensor chip in Biacore instruments was also examined. Creating a more hydrophilic surface layer on PDMS by oxidation was also examined.

When surfactants were continuously added to protein samples, as in dynamically coating of PDMS surfaces, Brij 35 resulted in the strongest reduction in protein adsorption. Brij 35 was also the surfactant that was easiest to remove from both PDMS and the sensor surfaces. Pluronic bound strongest to surfaces, and is most suitable when only adding surfactant to the buffer in a pre-coating step. All surfactants did reduce protein adsorption considerably (99% or more) and addition is necessary when working with protein solutions and hydrophobic surfaces as PDMS. Another alternative is oxidation of PDMS surface, which is an easy procedure that decreased the protein adsorption to about 10% compared to adsorption to untreated surface.

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50

Karbani, Najmunisa. "Roles of surfactant proteins, SP-A and SP-D, in pregnancy and parturition." Thesis, Brunel University, 2013. http://bura.brunel.ac.uk/handle/2438/8748.

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Abstract:

Surfactant proteins SP-A and SP-D are important key molecules responsible for pulmonary homeostasis and innate immunity against infectious pathogens. SP-A and SP-D are also found in various parts of the placenta as well as amniotic fluid. The levels of these proteins in the amniotic fluid are good biomarkers of fetal lung maturation. The development of the lungs in fetal growth is important for fetal survival in extrauterine life. In pregnant mice models, a huge increase in SP-A and SP-D levels in the amniotic sac has been reported close to parturition suggesting an important role of these proteins in the hormonal pathway to labour. In this thesis, full length natural and recombinant proteins of human SP-A and SP-D were generated and examined on the maternal-fetal tissues of the placenta (explants of amnion, chorion and decidua) under inflammatory conditions. A range of innate and adaptive immune markers and prostaglandin targets were examined to show that SP-A and SP-D modulate the prostaglandin pathway. Thus, an imbalance in this could potentially lead to disorders such as intrauterine growth retardation and preeclampsia. The cellular basis of immune regulation and prostaglandin pathway was also examined via fractionation of decidual macrophages. Curiously, SP-A and SP-D appears to suppress pro-inflammatory response of decidual macrophages after challenging with LPS. This thesis thus divulges specific and mutually inclusive functions of SP-A and SP-D in the maintenance of pregnancy, protection against intrauterine infection, dampening of inflammation, and premature activation of parturition.

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Dissertations / Theses on the topic 'Protein-Surfactant'

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