title: Identification of disulfide bonds in the ninth component (C9) of human complement.
abstract: C9 is the most abundant protein of the membrane attack complex of complement. By means of limited proteolysis, different chromatographic techniques, a thiol-specific fluorescence assay, amino acid analysis, and Edman degradation 9 out of 12 disulfide bridges are definitely assigned (Cys22-Cys57, Cys33-Cys36, Cys67-Cys73, Cys121-Cys160, Cys233- Cys234, Cys359-Cys384, Cys489-Cys505, Cys492-Cys507, Cys509-Cys518). Weaker evidence permits to reduce the number of possible configurations for the remaining 3 cystines (Cys80-Cys91, Cys86-Cys104, Cys98-Cys113, or Cys80-Cys91, Cys86-Cys113, Cys98-Cys104). These findings are discussed in comparison with the strongly related components C6, C7, C8alpha, and C8beta.
authors.affiliation: Institute of Biochemistry, University of Bern, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Lengweiler
authors.forename: J
authors.initials: J
authors.lastname: Schaller
authors.forename: E E
authors.initials: EE
authors.lastname: Rickli
mesh_terms: D000595:Amino Acid Sequence; D003186:Complement C9 / Q000737:chemistry*; D003488:Cyanogen Bromide; D003553:Cystine / Q000032:analysis / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry*; D010450:Endopeptidases; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D011487:Protein Conformation; D017421:Sequence Analysis
chemical_list: D003186:Complement C9; D004220:Disulfides; D010446:Peptide Fragments; D003553:Cystine; D010450:Endopeptidases; D003488:Cyanogen Bromide