Complement Factor I

Synonyms

C3b C4b Inactivator

C3b Inactivator

C3b-C4b Inactivator

C4b C3b INA

C4b-C3b Inactivator, Complement

C4b-C3b-INA

C4bC3bINA

Complement 3b Complement 4b Inactivator

Complement 3b-Complement 4b Inactivator

Complement C4b C3b Inactivator

Complement C4b-C3b Inactivator

Inactivator, C3b

Inactivator, C3b-C4b

Inactivator, Complement C4b-C3b

A plasma serine proteinase that cleaves the alpha-chains of C3b and C4b in the presence of the cofactors COMPLEMENT FACTOR H and C4-binding protein, respectively. It is a 66-kDa glycoprotein that converts C3b to inactivated C3b (iC3b) followed by the release of two fragments, C3c (150-kDa) and C3dg (41-kDa). It was formerly called KAF, C3bINF, or enzyme 3b inactivator.