Table 1 Complement regulatory proteins
From: Dynamic control of the complement system by modulated expression of regulatory proteins
Membrane-bound complement inhibitor | Mechanism of action |
|---|---|
CR1 (CD35) | Cofactor for factor I-mediated cleavage of C3b and C4b; accelerates decay of the C3 and C5 convertases. |
CRIg | Binds β chain of C3b and inhibits alternative pathway C3 and C5 convertases. |
Membrane cofactor protein (MCP; CD46) | Cofactor for factor I-mediated cleavage of C3b and C4b. |
Decay accelerating factor (DAF; CD55) | Accelerates the decay of C3 convertase. |
CD59 | Prevents formation of the membrane attack complex. |
Crry (rodent only) | Cofactor for factor I-mediated cleavage of C3b and C4b; accelerates the decay of the C3 convertases. |
Factor I | Soluble protein that mediates inactivating cleavage of C3b and C4b. |
Factor H | Soluble protein that can interact with host cell surfaces and inhibit alternative pathway C3 convertase. Factor H accelerates the decay of C3 convertase and also serves as a cofactor for factor I-mediated cleavage of C3b. |
