GOAT ANTI HUMAN C4

C4

TRIS buffered saline pH7. 4

Purified human C4

C4 plays a central role in the activation of the classical pathway of the complement system. It is processed by activated C1 which removes from the alpha chain the C4a anaphylatoxin. The remaining alpha chain fragment C4b is the major activation product and is an essential subunit of the C3 convertase (C4b2a) and the C5 convertase (C3bC4b2a) enzymes of the classical complement pathway. Derived from proteolytic degradation of complement C4 C4a anaphylatoxin is a mediator of local inflammatory process. It induces the contraction of smooth muscle increases vascular permeability and causes histamine release from mast cells and basophilic leukocytes. Subunit structureCirculates in blood as a disulfide-linked trimer of an alpha beta and gamma chain. Subcellular locationSecreted. Post-translational modificationPrior to secretion the single-chain precursor is enzymatically cleaved to yield the non-identical chains (alpha beta and gamma). During activation the alpha chain is cleaved by C1 into C4a and C4b and C4b stays linked to the beta and gamma chains. Further degradation of C4b by C1 into the inactive fragments C4c and C4d blocks the generation of C3 convertase. N- and O-glycosylated. O-glycosylated with a core 1 or possibly core 8 glycan. Ref. 15Ref. 16Ref. 18Ref. 19Ref. 20Ref. 21

C4A allotypes react more rapidly with the amino group of peptide antigens while C4B allotypes react more rapidly with the hydroxyl group of carbohydrate antigens. Sequence similaritiesContains 1 anaphylatoxin-like domain. Contains 1 NTR domain.