Identification of disulfide bonds in the ninth component (C9) of human complement.
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.
Lengweiler
S
S
Institute of Biochemistry, University of Bern, Switzerland.
Schaller
J
J
Rickli
E E
EE
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
D003186:Complement C9; D004220:Disulfides; D010446:Peptide Fragments; D003553:Cystine; D010450:Endopeptidases; D003488:Cyanogen Bromide