||Recombinant Human C4A protein, fused to GST-tag, was expressed in E.coli and purified by GSH-sepharose.
||This gene encodes the acidic form of complement factor 4, part of the classical activation pathway. The protein is expressed as a single chain precursor which is proteolytically cleaved into a trimer of alpha, beta, and gamma chains prior to secretion. The trimer provides a surface for interaction between the antigen-antibody complex and other complement components. The alpha chain may be cleaved to release C4 anaphylatoxin, a mediator of local inflammation. Deficiency of this protein is associated with systemic lupus erythematosus and type I diabetes mellitus. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. Varying haplotypes of this gene cluster exist, such that individuals may have 1, 2, or 3 copies of this gene. Two transcript variants encoding different isoforms have been found for this gene.
||The protein is stored in PBS buffer at -20℃. Avoid repeated freezing and thawing cycles.
||1M PBS (58mM Na2HPO4,17mM NaH2PO4, 68mM NaCl, pH8. ) added with 100mM GSH and 1% Triton X-100,15%glycerol.