. "Reviewed: D'Eustachio, P, 2006-07-03 21:35:13"^^ . "Authored: de Bono, B, 2004-08-04 09:17:50"^^ . "The same complexes as for C3 activation are employed for the cleavage of C5. C3 convertases with an additional C3b molecule covalently deposited in the immediate vicinity form the C5 convertases C3b,Bb,C3b and C4b,2a,3b, respectively. The second C3b acts like an anvil for C5: it interacts with C5 and presents C5 in the correct conformation for cleavage by the C2a or Bb enzyme."^^ . . . . . . "Activation of C5"^^ . "3.4.21"^^ . . . .