title: A study of the interactions between residues in the C-terminal half of calmodulin by one and two-dimensional NMR methods and computer modelling.
abstract: Assignments of the six sets of aromatic ring protons and four high-field-shifted methyl group protons of the C-terminal fragment of calmodulin, residues 78-148, was achieved by a combination of one and two-dimensional NMR spectroscopic methods. A full spectral analysis of the aromatic region in terms of chemical shifts and scalar coupling constants was achieved and confirmed by spectral simulation. A three-dimensional structural model of the C-terminal fragment was constructed by interactive computer graphics techniques and combined with nuclear Overhauser enhancements to propose sequence assignments for all aromatic and high-field-shifted methyl groups. This computer-generated three-dimensional model was generally supported by the fact that it qualitatively accounted for many of the ring-current-shifted proton resonances and the intraresidue and interresidue nuclear Overhauser enhancements.
mesh_terms: D000818:Animals; D001059:Apoproteins / Q000302:isolation & purification*; D002147:Calmodulin; D002417:Cattle; D003201:Computers; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry; D008958:Models, Molecular; D010446:Peptide Fragments / Q000302:isolation & purification; D011487:Protein Conformation; D011522:Protons; D013737:Testis / Q000032:analysis
chemical_list: D001059:Apoproteins; D002147:Calmodulin; D010446:Peptide Fragments; D011522:Protons