title: Nuclear magnetic resonance determination of metal-proton distances in a synthetic calcium binding site of rabbit skeletal troponin C.
abstract: The binding of gadolinium to a synthetic peptide of 13 amino acid residues representing the calcium binding loop of site 3 of rabbit skeletal troponin C [AcSTnC(103-115)amide] has been studied by using proton nuclear magnetic resonance (1H NMR) spectroscopy. In particular, the proton line broadening and enhanced spin-lattice relaxation have been used to determine proton-metal ion distances for several assigned nuclei in the peptide-metal ion complex. These distances have been used in conjunction with other constraints and a distance algorithm procedure to demonstrate that the structure of the peptide-metal complex as shown by 1H NMR is consistent with the structure of the EF calcium binding loop in the X-ray structure of parvalbumin but that the available 1H NMR distances do not uniquely define the solution structure.
authors.forename: J
authors.initials: J
authors.lastname: Gariépy
authors.forename: L E
authors.initials: LE
authors.lastname: Kay
authors.forename: I D
authors.initials: ID
authors.lastname: Kuntz
authors.forename: B D
authors.initials: BD
authors.lastname: Sykes
authors.forename: R S
authors.initials: RS
authors.lastname: Hodges
mesh_terms: D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D005682:Gadolinium; D007811:Lanthanum; D009682:Magnetic Resonance Spectroscopy; D010446:Peptide Fragments; D011522:Protons; D011817:Rabbits; D014336:Troponin; D019209:Troponin C
chemical_list: D010446:Peptide Fragments; D011522:Protons; D014336:Troponin; D019209:Troponin C; D007811:Lanthanum; D005682:Gadolinium; D002118:Calcium