Proteolytic transformation of SC5b-9 into an amphiphilic macromolecule resembling the C5b-9 membrane attack complex of complement

Abstract

Proteolysis of fluid-phase SC5b-9 left a major part of the macromolecule intact and caused transition of the molecule from a hydrophilic to an amphiphilic state. The transformed complex exhibited neoantigens characteristic of the C5b-9 membrane attack complex of the complement. It yielded an SDS gel electrophoresis pattern that was similar, but not identical to that of the proteolysed, membrane attack complex. The proteolytically altered SC5b-9 complex bound lipid and incorporated into artificial lipid vesicles to yield a membrane-bound structure resembling the C5b-9 complement lesion.