. "Authored: Jupe, S, 2010-10-26"^^ . "Edited: Jupe, S, 2010-11-01"^^ . "Reviewed: Fraczek, LA, 2012-02-13"^^ . "Reviewed: Bradley, DT, 2012-02-13"^^ . "Following the displacement of Bb from C3bBb, Factor I cleaves Factor H-bound C3b producing iC3b, which remains bound to the membrane. The majority of the C3b alpha chain is retained as two fragments which are tethered to the beta chain by disulphide bonds. iC3b is proteolytically inactive and cannot contribute to the complement cascade process, though it still contributes to opsonization."^^ . . . . . . . "Factor I inactivates Factor H-boundC3b"^^ . "3.4.21"^^ . . . . . .