c4a การใช้

• The anaphylatoxins C3a, C4a, and C5a are cationic fragments generated during the complement cascade that participate in host defense.
• Though interestingly, at this point in time, the genomic and derived amino acid sequence of either C4A or C4B had yet to be determined.
• The size of either C4A or C4B gene can be 21 kb ( long, L ) or 14.6 kb ( short, S ).
• The C3a, C4a and C5a components are referred to as anaphylatoxins : they cause smooth muscle contraction, histamine release from mast cells, and enhanced vascular permeability.
• Originally defined in the context of the Chido / Rodgers blood group system, the C4A-C4B genetic model is under investigation for its possible role in schizophrenia risk and development.
• It is present in the first locus ( coding for C4A ) for all C4 genes and in the second locus ( coding for C4B ) only in a few C4 genes.
• Biochemically, they also found that C4A reacted more steadily with an antibody s amino acid side chains and antigens that are amino groups, while C4B reacted better with carbohydrate hydroxyl groups.
• The membrane attack complex forms after c3b has bound to the surface of the target pathogen and is able to bind to c4a, which was formed earlier, and an enzyme called c5 convertase.
• Yet, the C4 protein derives from a simple two-locus allelic model, the C4A-C4B genes, that allows for an abundant variation in the levels of their respective proteins within a population.
• For example, single nucleotide polymorphisms were detected, which allowed them to be class differences between C4A and C4B . Furthermore, class and allelic differences would affect the performance of the C4 proteins with the immune complex.
• In order to activate the complement system when MBL binds to its target ( for example, mannose on the surface of a bacterium ), the MASP protein functions to cleave the blood protein C4 into C4a and C4b.
• They found out two features : 1 ) A great number of SNPs reaching only 2Mb across the end, 2 ) peak of association centered at C4, predicting that C4A expression levels is most strongly correlated with schizophrenia.
• GR requires FAD and NADPH to facilitate this reaction; first a hydride must be transferred from NADPH to FAD . The reduced flavin can then act as a nucleophile to attack the disulfide, this forms the C4a-cysteine adduct.
• When the carbohydrate-recognising heads of MBL bind to specifically arranged mannose residues on the surface of a pathogen, MASP-2 is activated to cleave complement components C4 and C2 into C4a, C4b, C2a, and C2b.
• In the same year, studies relatedly identified a 98 kb region of the chromosome the four class III genes ( that express C4A, C4B, C2, and factor B ) are closely linked, which does not allow for cross-overs to occur.
• More specifically, the C4B has shown to react much more efficiently and effectively despite the 7 kb difference between C4A and C4B . In whole serum, C4B alleles performed at a rate several fold greater during hemolytic activity, in direct comparison with C4A alleles.
• More specifically, the C4B has shown to react much more efficiently and effectively despite the 7 kb difference between C4A and C4B . In whole serum, C4B alleles performed at a rate several fold greater during hemolytic activity, in direct comparison with C4A alleles.
• To provide more context, in the latter study, the previously noted bimodular structure ( C4A-C4B ) has been updated to a quadrimodular structure of one to four discrete segments, containing one or more RP-C4-CYP21-TNX ( RCCX ) modules.
• In a study by Roos et al ., the ?-chains between the C4A and C4B were found to be slightly different ( MW of ~ 96, 000 and 94, 000, respectively ), proving that there is actually a structural difference between the two variants.
• For example, the Caucasian population studied showed 69 % bimodular configuration ( C4A-C4B, C4A-C4A, or C4B-C4B ) and 31 % trimodular configuration ( equally split between LLL as C4A-C4A-C4B or LSS as C4A-C4B-C4B ).