Interaction of bepridil with the cardiac troponin C/troponin I complex.
Article Details
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Abusamhadneh E, Abbott MB, Dvoretsky A, Finley N, Sasi S, Rosevear PR
Interaction of bepridil with the cardiac troponin C/troponin I complex.
FEBS Lett. 2001 Sep 28;506(1):51-4.
- PubMed ID
- 11591369 [ View in PubMed]
- Abstract
We have investigated the binding of bepridil to calcium-saturated cardiac troponin C in a cardiac troponin C/troponin I complex. Nuclear magnetic resonance spectroscopy and [(15)N,(2)H]cardiac troponin C permitted the mapping of bepridil-induced amide proton chemical shifts. A single bepridil-binding site in the regulatory domain was found with an affinity constant of approximately 140 microM(-1). In the presence of cardiac troponin I, bepridil binding to the C domain of cardiac troponin C was not detected. The pattern of bepridil-induced chemical shifts is consistent with stabilization of more open regulatory domain conformational states. A similar pattern of chemical shift perturbations was observed for interaction of the troponin I cardiac-specific amino-terminus with the cardiac troponin C regulatory domain. These results suggest that both bepridil and the cardiac-specific amino-terminus may mediate an increase in calcium affinity by interacting with and stabilizing open regulatory domain conformations. Chemical shift mapping suggests a possible role for inactive calcium-binding site I in the modulation of calcium affinity.
DrugBank Data that Cites this Article
- Drug Targets
Drug Target Kind Organism Pharmacological Action Actions Bepridil Troponin C, slow skeletal and cardiac muscles Protein Humans UnknownOtherDetails