Complement Factor H-ligand interactions: Self-association, multivalency and dissociation constants

Factor H (FH) is the major plasma regulator of the central complement protein C3b in the alternative pathway of complement activation. The elucidation of the FH interactions with five major ligands (below) is complicated by their weak μM dissociation constants KD and FH multivalency. We present the first survey of all the KD values for the major FH-ligand interactions and critically review their physiological significance.