Complement C3d

**Definition:** A 302-amino-acid fragment in the alpha chain (672-1663) of C3b. It is generated when C3b is inactivated (iC3b) and its alpha chain is cleaved by COMPLEMENT FACTOR I into C3c, and C3dg (955-1303) in the presence COMPLEMENT FACTOR H. Serum proteases further degrade C3dg into C3d (1002-1303) and C3g (955-1001).

**Tree numbers:** - D12.776.124.486.274.250.260.750

**Synonyms:** - C3d Complement - Complement 3d - Complement C3d Fragment - Complement Component 3d