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Abstract 


The ultrastructure of the membrane attack complex (MAC) of complement had been described as representing a hollow cylinder of defined dimensions that is composed of the proteins C5b, C6, C7, C8, and C9. After the characteristic cylindrical structure was identified as polymerized C9 [poly(C9)], the question arose as to the ultrastructural identity and topology of the C9-polymerizing complex C5b-8. An electron microscopic analysis of isolated MAC revealed an asymmetry of individual complexes with respect to their length. Whereas the length of one boundary (+/- SEM) was always 16 +/- 1 nm, the length of the other varied between 16 and 32 nm. In contrast, poly(C9), formed spontaneously from isolated C9, had a uniform tubule length (+/- SEM) of 16 +/- 1 nm. On examination of MAC-phospholipid vesicle complexes, an elongated structure was detected that was closely associated with the poly(C9) tubule and that extended 16-18 nm beyond the torus of the tubule and 28-30 nm above the membrane surface. The width of this structure varied depending on its two-dimensional projection in the electron microscope. By using biotinyl C5b-6 in the formation of the MAC and avidin-coated colloidal gold particles for the ultrastructural analysis, this heretofore unrecognized subunit of the MAC could be identified as the tetramolecular C5b-8 complex. Identification also was achieved by using anti-C5 Fab-coated colloidal gold particles. A similar elongated structure of 25 nm length (above the surface of the membrane) was observed on single C5b-8-vesicle complexes. It is concluded that the C5b-8 complex, which catalyzes poly(C9) formation, constitutes a structure of discrete morphology that remains as such identifiable in the fully assembled MAC, in which it is closely associated with the poly(C9) tubule.

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Proc Natl Acad Sci U S A. 1982 Dec; 79(23): 7474–7478.
PMCID: PMC347362
PMID: 6961424

Ultrastructure of the membrane attack complex of complement: detection of the tetramolecular C9-polymerizing complex C5b-8.

Abstract

The ultrastructure of the membrane attack complex (MAC) of complement had been described as representing a hollow cylinder of defined dimensions that is composed of the proteins C5b, C6, C7, C8, and C9. After the characteristic cylindrical structure was identified as polymerized C9 [poly(C9)], the question arose as to the ultrastructural identity and topology of the C9-polymerizing complex C5b-8. An electron microscopic analysis of isolated MAC revealed an asymmetry of individual complexes with respect to their length. Whereas the length of one boundary (+/- SEM) was always 16 +/- 1 nm, the length of the other varied between 16 and 32 nm. In contrast, poly(C9), formed spontaneously from isolated C9, had a uniform tubule length (+/- SEM) of 16 +/- 1 nm. On examination of MAC-phospholipid vesicle complexes, an elongated structure was detected that was closely associated with the poly(C9) tubule and that extended 16-18 nm beyond the torus of the tubule and 28-30 nm above the membrane surface. The width of this structure varied depending on its two-dimensional projection in the electron microscope. By using biotinyl C5b-6 in the formation of the MAC and avidin-coated colloidal gold particles for the ultrastructural analysis, this heretofore unrecognized subunit of the MAC could be identified as the tetramolecular C5b-8 complex. Identification also was achieved by using anti-C5 Fab-coated colloidal gold particles. A similar elongated structure of 25 nm length (above the surface of the membrane) was observed on single C5b-8-vesicle complexes. It is concluded that the C5b-8 complex, which catalyzes poly(C9) formation, constitutes a structure of discrete morphology that remains as such identifiable in the fully assembled MAC, in which it is closely associated with the poly(C9) tubule.

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Selected References

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  • Kolb WP, Haxby JA, Arroyave CM, Müller-Eberhard HJ. Molecular analysis of the membrane attack mechanism of complement. J Exp Med. 1972 Mar 1;135(3):549–566. [Europe PMC free article] [Abstract] [Google Scholar]
  • Kolb WP, Müller-Eberhard HJ. The membrane attack mechanism of complement. Verification of a stable C5-9 complex in free solution. J Exp Med. 1973 Aug 1;138(2):438–451. [Europe PMC free article] [Abstract] [Google Scholar]
  • Bhakdi S, Ey P, Bhakdi-Lehnen B. Isolation of the terminal complement complex from target sheep erythrocyte membranes. Biochim Biophys Acta. 1976 Feb 6;419(3):445–457. [Abstract] [Google Scholar]
  • Kolb WP, Muller-Eberhard HJ. The membrane attack mechanism of complement. Isolation and subunit composition of the C5b-9 complex. J Exp Med. 1975 Apr 1;141(4):724–735. [Europe PMC free article] [Abstract] [Google Scholar]
  • Podack ER, Müller-Eberhard HJ. Binding of desoxycholate, phosphatidylcholine vesicles, lipoprotein and of the S-protein to complexes of terminal complement components. J Immunol. 1978 Sep;121(3):1025–1030. [Abstract] [Google Scholar]
  • Esser AF, Kolb WP, Podack ER, Müller-Eberhard HJ. Molecular reorganization of lipid bilayers by complement: a possible mechanism for membranolysis. Proc Natl Acad Sci U S A. 1979 Mar;76(3):1410–1414. [Europe PMC free article] [Abstract] [Google Scholar]
  • Mayer MM. Mechanism of cytolysis by complement. Proc Natl Acad Sci U S A. 1972 Oct;69(10):2954–2958. [Europe PMC free article] [Abstract] [Google Scholar]
  • Podack ER, Müller-Eberhard HJ, Horst H, Hoppe W. Membrane attach complex of complement (MAC): three-dimensional analysis of MAC-phospholipid vesicle recombinants. J Immunol. 1982 May;128(5):2353–2357. [Abstract] [Google Scholar]
  • BORSOS T, DOURMASHKIN RR, HUMPHREY JH. LESIONS IN ERYTHROCYTE MEMBRANES CAUSED BY IMMUNE HAEMOLYSIS. Nature. 1964 Apr 18;202:251–252. [Abstract] [Google Scholar]
  • Humphrey JH, Dourmashkin RR. The lesions in cell membranes caused by complement. Adv Immunol. 1969;11:75–115. [Abstract] [Google Scholar]
  • Tranum-Jensen J, Bhakdi S, Bhakdi-Lehnen B, Bjerrum OJ, Speth V. Complement lysis: the ultrastructure and orientation of the C5b-9 complex on target sheep erythrocyte membranes. Scand J Immunol. 1978;7(1):45–46. [Abstract] [Google Scholar]
  • Biesecker G, Podack ER, Halverson CA, Müller-Eberhard HJ. C5b-9 dimer: isolation from complement lysed cells and ultrastructural identification with complement-dependent membrane lesions. J Exp Med. 1979 Feb 1;149(2):448–458. [Europe PMC free article] [Abstract] [Google Scholar]
  • Podack ER, Esser AF, Biesecker G, Müller-Eberhard HJ. Membrane attack complex of complement: a structural analysis of its assembly. J Exp Med. 1980 Feb 1;151(2):301–313. [Europe PMC free article] [Abstract] [Google Scholar]
  • Podack ER, Stoffel W, Esser AF, Müller-Eberhard HJ. Membrane attack complex of complement: distribution of subunits between the hydrocarbon phase of target membranes and water. Proc Natl Acad Sci U S A. 1981 Jul;78(7):4544–4548. [Europe PMC free article] [Abstract] [Google Scholar]
  • Hu VW, Esser AF, Podack ER, Wisnieski BJ. The membrane attack mechanism of complement: photolabeling reveals insertion of terminal proteins into target membrane. J Immunol. 1981 Jul;127(1):380–386. [Abstract] [Google Scholar]
  • Tschopp J, Podack ER. Membranolysis by the ninth component of human complement. Biochem Biophys Res Commun. 1981 Jun 16;100(3):1409–1414. [Abstract] [Google Scholar]
  • Podack ER, Tschopp J. Polymerization of the ninth component of complement (C9): formation of poly(C9) with a tubular ultrastructure resembling the membrane attack complex of complement. Proc Natl Acad Sci U S A. 1982 Jan;79(2):574–578. [Europe PMC free article] [Abstract] [Google Scholar]
  • Tschopp J, Müller-Eberhard HJ, Podack ER. Formation of transmembrane tubules by spontaneous polymerization of the hydrophilic complement protein C9. Nature. 1982 Aug 5;298(5874):534–538. [Abstract] [Google Scholar]
  • Podack ER, Tschoop J, Müller-Eberhard HJ. Molecular organization of C9 within the membrane attack complex of complement. Induction of circular C9 polymerization by the C5b-8 assembly. J Exp Med. 1982 Jul 1;156(1):268–282. [Europe PMC free article] [Abstract] [Google Scholar]
  • Podack ER, Müller-Eberhard HJ. Limited proteolysis of C5b-6: functional stability of the degraded complex. J Immunol. 1980 Jan;124(1):332–336. [Abstract] [Google Scholar]
  • Podack ER, Kolb WP, Esser AF, Müller-Eberhard HJ. Structural similarities between C6 and C7 of human complement. J Immunol. 1979 Sep;123(3):1071–1077. [Abstract] [Google Scholar]
  • Klob WP, Müller-Eberhard HJ. The membrane attack mechanism of complement: the three polypeptide chain structure of the eigth component (C8). J Exp Med. 1976 May 1;143(5):1131–1139. [Europe PMC free article] [Abstract] [Google Scholar]
  • Biesecker G, Müller-Eberhard HJ. The ninth component of human complement: purification and physicochemical characterization. J Immunol. 1980 Mar;124(3):1291–1296. [Abstract] [Google Scholar]
  • Horisberger M, Rosset J, Bauer H. Colloidal gold granules as markers for cell surface receptors in the scanning electron microscope. Experientia. 1975 Oct 15;31(10):1147–1149. [Abstract] [Google Scholar]
  • Podack ER, Müller-Eberhard HJ. Membrane attack complex of complement. Evidence for its dimeric structure based on hybrid formation. J Biol Chem. 1981 Apr 10;256(7):3145–3148. [Abstract] [Google Scholar]
  • Sundsmo JS, Müller-Eberhard HJ. Neoantigen of the complement membrane attack complex of cytotoxic human peripheral blood lymphocytes. J Immunol. 1979 Jun;122(6):2371–2378. [Abstract] [Google Scholar]
  • Dourmashkin RR. The structural events associated with the attachment of complement components to cell membranes in reactive lysis. Immunology. 1978 Aug;35(2):205–212. [Abstract] [Google Scholar]
  • Mayer MM. Complement, past and present. Harvey Lect. 1978;72:139–193. [Abstract] [Google Scholar]
  • Bhakdi S, Tranum-Jensen J. Molecular nature of the complement lesion. Proc Natl Acad Sci U S A. 1978 Nov;75(11):5655–5659. [Europe PMC free article] [Abstract] [Google Scholar]

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Funders who supported this work.

NCI NIH HHS (1)

NIAID NIH HHS (2)