Influence of association and of positive inotropic drugs on calcium binding to cardiac troponin C.
Isolated bovine cardiac troponin C forms dimers in presence of Mg2+ dependent on the protein concentration which has been determined by sedimentation velocity and sedimentation equilibrium. Dimer formation is correlated with a decrease in Ca2+ affinity. Positive inotropic drugs (benzimidazol derivatives) influence Ca2+ sensitivity either by changing the association state or by affecting the Ca2+ binding properties directly.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002417:Cattle; D007700:Kinetics; D046911:Macromolecular Substances; D009206:Myocardium / Q000378:metabolism*; D011485:Protein Binding; D014336:Troponin / Q000378:metabolism*; D019209:Troponin C
D002316:Cardiotonic Agents; D046911:Macromolecular Substances; D014336:Troponin; D019209:Troponin C; D002118:Calcium