Tags: Protein.
Complement C4-A is a protein that in humans is encoded by the C4A gene.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.