EC Number   |
Activating Compound |
Reference |
|---|
   3.4.21.47 | factor B |
generation of the AP C3-convertase initiates by the binding of factor B to C3b to form the proconvertase, C3bB. Factor B undergoes a dramatic conformational change upon binding to C3b, it binds near the C345C domain in C3b. Factor B-D279G mutant promotes high-affinity C3b-binding and is correctly cleaved by factor D in the C3bB proenzyme to generate a very stable, functionally-active, AP C3-convertase C3bBb |
701017 |
| 3.4.21.47 | factor B |
the classical C5 convertase requires factor D and factor B for activation and complex assembly |
732705 |
| 3.4.21.47 | factor C |
acts as an LPS-responsive C3 convertase on the surface of invading Gram-negative bacteria in the initial phase of horseshoe crab complement activation. The proteolytic activity of factor C on the surface of Escherichia coli is essential for the deposition of C3b |
699342 |
| 3.4.21.47 | factor D |
the classical C5 convertase requires factor D and factor B for activation and complex assembly |
732705 |
| 3.4.21.47 | factor D |
the proconvertase C3bB is cleaved by factor D at a single site in factor B, producing Ba and Bb fragments. Ba dissociates from the complex, while Bb remains bound to C3b, forming the active AP C3-convertase C3bBb |
701017 |
| 3.4.21.47 | formyl-methionyl-leucylphenylalanine |
treatment of whole blood leads to stimulation of neutrophils resulting in activation of the alternative complement pathway and release of C5 fragments, which further amplify proinflammatory responses |
717421 |
| 3.4.21.47 | human complement factor H-related protein 4 |
CFHR 4, two isozymes A and B of 86 and 45 kDa from plasma, domain structure, overview. The protein belongs to the factor H family of plasma glycoproteins that are composed of short consensus repeat (SCR) domains. It activates complement by serving as a platform for the assembly of alternative pathway C3 convertase via its interaction with C3b protein. CFHR4 binds C3b via its C-terminus, and it lacks SCRs homologous to the complement inhibitory domains of factor H and has no significant complement regulatory activities. In contrast to the complement inhibitor factor H, CFHR4 acts as an enhancer of opsonization by promoting complement activation |
732056 |
| 3.4.21.47 | LPS |
proteolytic conversion of C3 to C3b in hemocyanin-depleted plasma is strongly induced by LPS |
699342 |
| 3.4.21.47 | mannan-binding lectin |
binding to O antigen-specific oligosaccharides derived from Salmonella sp. corresponding to serogroup C, and efficient support of component C3 deposition in the absence of C2, C4, or the associated serine protease 2 |
669628 |
| 3.4.21.47 | mannan-binding lectin |
mannan-binding lectin (MBL) promotes activation of complement component C3 through the combined action of MBL-associated serine proteases MASP-1 and MASP-2 without appreciable involvement of the alternative pathway |
680169 |
