title: Evidence for the influence of the initial complement components on the assembly and activity of the membrane attack complex.
abstract: The failure of functionally purified C5gp to reconstitute the hemolytic complement (C) activity of C5-deficient human serum was studied. The lack of hemolytic activity of C5gp in this system could not be correlated with the failure of EAC1-3hu to bind and activate C5gp, but was related to the failure of EAC1-3hu5gp6hu to efficiently bind C7hu in a form that would lead to lysis when HuC8 and HuC9 were added. This failure was not observed with EAC1-3gp5gp6hu or EAC1-3hu5hu6hu, which could be lysed with any combination of human or guinea pig C7 through C9. The implications of these findings on the control of the lytic C attack mechanism by the initial components in the C cascade are discussed.
mesh_terms: D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000276:immunology; D003182:Complement C5 / Q000172:deficiency; D003165:Complement System Proteins; D006168:Guinea Pigs; D006461:Hemolysis; D006801:Humans; D011817:Rabbits; D013997:Time Factors
chemical_list: D003182:Complement C5; D003165:Complement System Proteins