Sites of intra- and intermolecular cross-linking of the N-terminal extension of troponin I in human cardiac whole troponin complex.

ABSTRACT: Our previous studies (Howarth, J. W., Meller, J., Solaro, R. J., Trewhella, J., and Rosevear, P. R. (2007) J. Mol. Biol. 373, 706-722) of the unique N-terminal region of human cardiac troponin I (hcTnI), predicted a possible intramolecular interaction near the basic inhibitory peptide. To explore this possibility, we generated single cysteine mutants (hcTnI-S5C and hcTnI-I19C), which were labeled with the hetero-bifunctional cross-linker benzophenone-4-maleimide. The labeled hcTnI was reconstituted to whole troponin and exposed to UV light to form cross-linked proteins. Reversed-phase high-performance liquid chromatography and SDS-PAGE indicated intra- and intermolecular cross-linking with hcTnC and hcTnT. Moreover, using tandem mass spectrometry and Edman sequencing, specific intramolecul

SUBMITTER: Warren CM 

PROVIDER: S-EPMC2682874 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature