Identification of an intramolecular cross-link in troponin C after cross-linking the troponin complex with 1,3-difluoro-4,6-dinitrobenzene.
The troponin complex isolated from rabbit skeletal muscle was cross-linked with 1,3-difluoro-4,6-dinitrobenzene, subjected to tryptic hydrolysis, and the labelled peptides were separated. One peptide was purified to homogeneity; it proved to be peptide Gly(89)-Arg(100) of troponin C on the basis of amino acid composition and N-terminal analysis. The absorption spectrum of this peptide between 300 and 500 nm was very similar to that of 1-(S-cysteinyl)-5-(N epsilon-lysyl)-2,4-dinitrobenzene, which could only be due to cross-link formation between Lys-90 and Cys-98. This finding is interpreted in terms of the proposed tertiary structure of troponin C.
D055598:Chemical Phenomena; D002621:Chemistry; D003432:Cross-Linking Reagents; D004139:Dinitrofluorobenzene / Q000031:analogs & derivatives; D009124:Muscle Proteins; D011487:Protein Conformation; D014336:Troponin
D003432:Cross-Linking Reagents; D009124:Muscle Proteins; D014336:Troponin; D004139:Dinitrofluorobenzene; C002041:1,5-difluoro-2,4-dinitrobenzene