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Effect of troponin C on the cooperativity in Ca 2+ activation of cardiac muscle
Author(s) -
Gulati Jagdish,
Scordilis Stylianos,
Babu Arvind
Publication year - 1988
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(88)80073-5
Subject(s) - cooperativity , troponin , chemistry , troponin c , biophysics , medicine , cardiology , cardiac muscle , biochemistry , biology , myocardial infarction
This study describes the effects of exchanging native cardiac troponin C (CTnC) from the right ventricular muscle of Syrian hamster for purified skeletal (S) TnC from fast twitch muscles in triggering cardiac contraction. Ca 2+ sensitivity of the myocardium became decreased with STnC to 62% of the original value with CTnC. Furthermore, the slope of the p Ca ‐force curve of cardiac muscle was found to be increased with STnC. The results show that the TnC moiety, as part of the switching mechanism during activation, also regulates thin‐filament cooperativity in muscle. Modifications in both the Ca 2+ sensitivity and cooperativity are associated with alterations in the primary structure of TnC.