The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.
Use a concentration of 1 µg/ml. Detects a band of approximately 193 kDa (predicted molecular weight: 193 kDa).
Use at an assay dependent concentration. PubMed: 23236492
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.
Involvement in disease
Defects in C4A are the cause of complement component 4A deficiency (C4AD) [MIM:120810]. A rare defect of the complement classical pathway associated with the development of autoimmune disorders, mainly systemic lupus with or without associated glomerulonephritis.
Prior 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.
Complement C4-A is proteolytically cleaved to yield three non-identical chains and circulates in blood as a disulphide-linked trimer of an alpha, beta and gamma chain (95, 75 and 33 kDa respectively). We propose that the 95 kDa band corresponds to the alpha chain of Complement C4-A.