The attack phase of human complement: differentiation between membrane binding and complex formation by the detection of neoantigen expression in situ. A morphometric immunoferritin study.
C5-9 neoantigen was found by morphometric immunoferritin staining on the membrane of guinea pig erythrocytes lyzed by reactive lysis C5b6 or acid-activated C5 + C6 and C7, C8, and C9. Neoantigen first appeared at the C7 step, increasing with C8, and decreasing after the addition of C9. The incubation of E with C5-C8 or C5-C9 at 0 degrees C resulted in EC5-8 without neoantigen. Reincubation of these cells after washing at 37 degrees C for 5 min led to neoantigen expression. An energy-requiring step is postulated after binding of C5-C8 and needed for C9 binding and lysis.
D000818:Animals; D000941:Antigens; D001665:Binding Sites; D003167:Complement Activation; D003182:Complement C5; D003183:Complement C6; D003165:Complement System Proteins / Q000276:immunology*; D004910:Erythrocyte Membrane / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology*; D005293:Ferritins / Q000276:immunology*; D006168:Guinea Pigs; D006461:Hemolysis; D006801:Humans
D000941:Antigens; D003182:Complement C5; D003183:Complement C6; D003165:Complement System Proteins; D005293:Ferritins