title: Proton magnetic resonance studies on proteolytic fragments of troponin-C. Structural homology with the native molecule.
abstract: Comparison of proton magnetic resonance spectra of a tryptic and a thrombin fragment of troponin-C with that of the native protein has identified the domain of the molecule influenced by Ca2+ binding to the lower affinity regions I and II of troponin-C. The binding of Ca2+ to these sites results in a subtle alteration of the tertiary fold of the N-terminal half of troponin-C involving weakened contacts between several hydrophobic groups. The role and kinetics of the movements within the troponin-C molecule associated with binding at the regulatory sites are discussed.
mesh_terms: D000818:Animals; D001665:Binding Sites; D002118:Calcium; D009682:Magnetic Resonance Spectroscopy; D009124:Muscle Proteins / Q000502:physiology; D010446:Peptide Fragments; D011485:Protein Binding; D011487:Protein Conformation; D011817:Rabbits; D013917:Thrombin; D014336:Troponin / Q000502:physiology; D014357:Trypsin
chemical_list: D009124:Muscle Proteins; D010446:Peptide Fragments; D014336:Troponin; D014357:Trypsin; D013917:Thrombin; D002118:Calcium