Cell surface:C3b:Factor B complex Surface-associated C3bBb Factor D cleaves C3b-bound Factor B Authored: de Bono, B, 2006-07-21 15:55:23 EC Number: 3.4.21 Edited: Jupe, S, 2010-11-17 Factor D, a constitutively active serine protease found in trace amounts in the blood, cleaves a specific Arg-Lys bond in the Factor B component of the cell surface-associated C3b:Factor B complex, yielding the alternate C3 convertase C3bBb on the surface and releasing an inactive polypeptide, Factor Ba (Lesavre and Muller-Eberhard 1978; Lesavre et al. 1979; Schreiber et al. 1978). Pubmed279011 Pubmed3052276 Pubmed458145 Reactome Database ID Release 43183122 Reactome, http://www.reactome.org ReactomeREACT_8026 Reviewed: D'Eustachio, P, 2006-08-28 21:16:15