Mouse Complement 5a （C5a） is a glycoprotein which is a member of a family of structurally and functionally related proteins known as anaphylatoxins. C5a is a 77 a.a. peptide created by the C5a convertase proteolytic cleavage of C5 ? chain in the classical and alternative complement pathway （C4b2a3b， C3bBb3b）. The mouse C5a has four ? helices and three intrachain disulfide bonds which form a triple loop structure. C5a functions through G-protein coupled receptor （GPCR） （C5aR/CD88）. C5a is a effective chemoattractant and anaphylatoxin which functions on all classes of leukocytes and on many other cell types including endothelial， smooth muscle， kidney， liver， and neural cells. Mouse C5a also mediates IL-8 release from bronchial epithelial cells. Furthermore， it triggers an oxidative surge in macrophages and neutrophils， causing the release of histamine in basophils and mast cells. The C5a anaphylatoxin activity on hepatocytes results indirectly from interaction with nonparenchymal cell via prostanoid secretion.
