The C5b-9 Complex: Subunit Composition of the Classical and Alternative Pathway-Generated Complex

Abstract

The membrane attack complex of complement (C5b-9) is identical in composition regardless of which pathway of activation was instrumental in its formation. Band V protein was consitently a subunit of the soluble complex. Since band V protein is not required for complement-dependent cytolysis, it probably represents a membrane site equivalent in serum of the nascent C5b-9 complex.