outer surface protein C
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Chronické zánětlivé reakce probíhající v cévní stěně jsou podkladem vzniku aterosklerózy. C-reaktivní protein je snadno měřitelným ukazatelem aktivity těchto zánětlivých reakcí. Současně je CRP i jejich aktivním účastníkem. Postavení CRP v patogenezi aterosklerózy je dvojjediné: na samém počátku aterosklerotického procesu vykazuje CRP protizánětlivé účinky, které chrání cévní stěnu před ukládáním aterogenních lipoproteinů. Genetická dispozice organismu a vliv zevních rizikových faktorů mění tyto původně ochranné účinky CRP v účinky prozánětlivé, které podporují rozvoj aterosklerózy. Ochranné, protizánětlivé působení i prozánětlivé, aterogenní působení CRP je založeno na aktivaci komplementové kaskády. Ochranné působení CRP spočívá v aktivaci komplementu na úroveň fragmentů C3b/iC3b. Podmínkou je účast regulačního faktoru H. CRP může také přímo indukovat tvorbu membránových regulačních faktorů, mezi nimiž vyniká decay-accelerating factor. Membránové regulační faktory tvoří součást buněčných membrán, na prvním místě jmenujme membrány endotelových buněk, které tak jsou chráněny před autodestruktivními účinky aktivovaného komplementu. K plazmatickým regulačním faktorům se rovněž počítá clusterin/ apolipoproteinJ. Podle nových poznatků však tento působek patří mezi tzv. stresové proteiny, které se vyznačují celkově ochranným působením na buněčné struktury. Ochranné působení CRP založené na spolupráci s regulátory aktivace komplementu má obdobu v terapeutických účincích inhibitorů enzymu HMGCoA reduktázy neboli statinů.
Chronic inflammatory reactions which affect the arterial wall can be viewed as an underlying cause of atherosclerosis. C-reactive protein is an easily measurable marker which reflects the activity of inflammatory responses. At the same time, CRP represents an active partaker of the inflammatory process. The role CRP plays in the pathogenesis of atherosclerosis is ambivalent: at the very beginning, it displays anti-inflammatory properties which contribute to the protection of the arterial wall from atherogenic lipoproteins. Later on, genetic disposition of the host and the influence of many known risk factors convert CRP’s antiinflammatory activity into a net pro-inflammatory effect which boosts the development of atherosclerosis. Both the protective anti-inflammatory and the noxious pro-inflammatory activities of CRP reside in its capacity to activate the complement cascade. The protective effect of CRP, which is dependent on the plasmatic regulatory factor H, is carried out by the activation of complement up to the level of fragments C3b/iC3b. Further, CRP directly induces production of the complement membrane regulatory proteins, most important of which is the decay-accelerating factor. Membrane regulatory factors form an integral part of the outer cellular membrane, most importantly that of endothelial cells, resulting in protection of the latter from autodestructive attacks inflicted by activated complement. One of the complement regulatory factors is represented by clusterin/apolipoproteinJ. However, according to recent studies, clusterin/apoJ belongs rather to a group of stress proteins, which display overall protective effects on cellular protein structures. Protective activities of CRP based on its cooperation with complement regulatory factors are closely mimicked by the HMG-CoA reductase inhibitors or statins.
- MeSH
- arterioskleróza imunologie MeSH
- C-reaktivní protein imunologie MeSH
- komplement imunologie MeSH
- lidé MeSH
- membránové proteiny imunologie MeSH
- statiny farmakologie MeSH
- zánět imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
The aim of this work was isolation and purification of the major immunodominant protein, Outer surface protein C (OspC) of three members of the species group Borrelia burgdorferi, the causative agent of Lyme disease. Our aim was to obtain this protein in a quantity and purity sufficient for immunization of experimental animals. For optimalization of protein purification's yield we used immobilized metal ion affinity chromatography (IMAC) under different conditions. The greatest efficiency was achieved by using of HiTrap Chelating Column under native conditions.
- MeSH
- antigeny bakteriální biosyntéza izolace a purifikace MeSH
- DNA vakcíny biosyntéza izolace a purifikace MeSH
- Escherichia coli MeSH
- genetické vektory MeSH
- proteiny vnější bakteriální membrány biosyntéza izolace a purifikace MeSH
- vakcína proti lymeské nemoci biosyntéza izolace a purifikace MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The formation of biomolecular coronas around nanoparticles as soon as they come in contact with biological media is nowadays well accepted. The self-developed biological outer surfaces can affect the targeting capability of the colloidal carriers as well as their cytotoxicity and cellular uptake behavior. In this framework, we explored the structural features and biological consequences of protein coronas around block copolymer assemblies consisting of a common pH-responsive core made by poly[2-(diisopropylamino) ethyl methacrylate] (PDPA) and hydrophilic shells of different chemical natures: zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) or highly hydrophilic poly(ethylene oxide) (PEO) and poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA). We demonstrated the presence of ∼50 nm protein coronas around the nanoparticles regardless of the chemical nature of the polymeric shells. The thickness is understood as the sum of the soft and hard layers and it is the actual interface seen by the cells. Although the soft corona composition is difficult to determine because the proteins are loosely bound to the outer surface of the assemblies, the tightly bound proteins (hard corona) could be identified and quantified. The compositional analysis of the hard corona demonstrated that human serum albumin (HSA), immunoglobulin G (IgG) and fibrinogen are the main components of the protein coronas, and serotransferrin is present particularly in the protein corona of the zwitterionic-stabilized assemblies. The protein coronas substantially reduce the cellular uptake of the colloidal particles due to their increased size and the presence of HSA which is known to reduce nanoparticle-cell adhesion. On the other hand, their existence also reduces the levels of cytotoxicity of the polymeric assemblies, highlighting that protein coronas should not be always understood as artifacts that need to be eliminated due to their positive outputs.
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- lipoproteiny genetika metabolismus MeSH
- membránové proteiny genetika chemie metabolismus MeSH
- Neisseria meningitidis genetika MeSH
- proteiny vnější bakteriální membrány genetika metabolismus MeSH
- techniky in vitro MeSH
- vápník farmakologie MeSH
- železo metabolismus MeSH
The iron-regulated FrpD protein is a unique lipoprotein embedded into the outer membrane of the Gram-negative bacterium Neisseria meningitidis. The biological function of FrpD remains unknown but might consist in anchoring to the bacterial cell surface the Type I-secreted FrpC protein, which belongs to a Repeat in ToXins (RTX) protein family and binds FrpD with very high affinity (K(d) = 0.2 nM). Here, we report the backbone (1)H, (13)C, and (15)N chemical shift assignments for the FrpD(43-271) protein that allow us to characterize the intimate interaction between FrpD and the N-terminal domain of FrpC.
Dysfunction of TMEM70 disrupts the biogenesis of ATP synthase and represents the frequent cause of autosomal recessive encephalocardiomyopathy. We used tagged forms of TMEM70 and demonstrated that it has a hairpin structure with the N- and C-termini oriented towards the mitochondrial matrix. On BN-PAGE TMEM70 was detected in multiple forms including dimers and displayed partial overlap with assembled ATP synthase. Immunoprecipitation studies confirmed mutual interactions between TMEM70 molecules but, together with immunogold electron microscopy, not direct interaction with ATP synthase subunits. This indicates that the biological function of TMEM70 in the ATP synthase biogenesis may be mediated through interaction with other protein(s).
- MeSH
- buněčné linie MeSH
- imunoelektronová mikroskopie MeSH
- imunoprecipitace MeSH
- lidé MeSH
- membránové proteiny metabolismus MeSH
- mitochondriální membrány metabolismus MeSH
- mitochondriální proteiny metabolismus MeSH
- mitochondriální protonové ATPasy metabolismus MeSH
- multimerizace proteinu * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In recent years, considerable progress has been made in topologically and functionally characterizing integral outer membrane proteins (OMPs) of Treponema pallidum subspecies pallidum, the syphilis spirochete, and identifying its surface-exposed β-barrel domains. Extracellular loops in OMPs of Gram-negative bacteria are known to be highly variable. We examined the sequence diversity of β-barrel-encoding regions of tprC, tprD, and bamA in 31 specimens from Cali, Colombia; San Francisco, California; and the Czech Republic and compared them to allelic variants in the 41 reference genomes in the NCBI database. To establish a phylogenetic framework, we used T. pallidum 0548 (tp0548) genotyping and tp0558 sequences to assign strains to the Nichols or SS14 clades. We found that (i) β-barrels in clinical strains could be grouped according to allelic variants in T. pallidum subsp. pallidum reference genomes; (ii) for all three OMP loci, clinical strains within the Nichols or SS14 clades often harbored β-barrel variants that differed from the Nichols and SS14 reference strains; and (iii) OMP variable regions often reside in predicted extracellular loops containing B-cell epitopes. On the basis of structural models, nonconservative amino acid substitutions in predicted transmembrane β-strands of T. pallidum repeat C (TprC) and TprD2 could give rise to functional differences in their porin channels. OMP profiles of some clinical strains were mosaics of different reference strains and did not correlate with results from enhanced molecular typing. Our observations suggest that human host selection pressures drive T. pallidum subsp. pallidum OMP diversity and that genetic exchange contributes to the evolutionary biology of T. pallidum subsp. pallidum They also set the stage for topology-based analysis of antibody responses to OMPs and help frame strategies for syphilis vaccine development.IMPORTANCE Despite recent progress characterizing outer membrane proteins (OMPs) of Treponema pallidum, little is known about how their surface-exposed, β-barrel-forming domains vary among strains circulating within high-risk populations. In this study, sequences for the β-barrel-encoding regions of three OMP loci, tprC, tprD, and bamA, in T. pallidum subsp. pallidum isolates from a large number of patient specimens from geographically disparate sites were examined. Structural models predict that sequence variation within β-barrel domains occurs predominantly within predicted extracellular loops. Amino acid substitutions in predicted transmembrane strands that could potentially affect porin channel function were also noted. Our findings suggest that selection pressures exerted within human populations drive T. pallidum subsp. pallidum OMP diversity and that recombination at OMP loci contributes to the evolutionary biology of syphilis spirochetes. These results also set the stage for topology-based analysis of antibody responses that promote clearance of T. pallidum subsp. pallidum and frame strategies for vaccine development based upon conserved OMP extracellular loops.
- MeSH
- fylogeneze MeSH
- genetická variace MeSH
- lidé MeSH
- molekulární evoluce * MeSH
- molekulární sekvence - údaje MeSH
- proteinové domény MeSH
- proteiny vnější bakteriální membrány chemie genetika metabolismus MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- sekvenční seřazení MeSH
- Spirochaetales klasifikace genetika růst a vývoj izolace a purifikace MeSH
- syfilis mikrobiologie MeSH
- Treponema pallidum klasifikace genetika růst a vývoj izolace a purifikace MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
