title: Multiple-timescale dynamics of side-chain carboxyl and carbonyl groups in proteins by 13C nuclear spin relaxation.
abstract: Side-chain carboxyl and carbonyl groups play a major role in protein interactions and enzyme catalysis. A series of (13)C relaxation experiments is introduced to study the dynamics of carboxyl and carbonyl groups in protein side chains on both fast (sub-ns) and slower (micros-ms) time scales. This approach is illustrated on the protein calbindin D(9k). Fast dynamics features correlate with hydrogen- and ion-binding patterns. We also identify chemical dynamics on micros time scales in solvent-exposed carboxyl groups, most probably due to exchange between the carboxylate and carboxylic acid forms.
authors.affiliation: Département de Chimie, associé au CNRS, Ecole Normale Supérieure, 24, rue Lhomond, 75231 Paris Cedex 05, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Paquin
authors.forename: Fabien
authors.initials: F
authors.lastname: Ferrage
authors.forename: Frans A A
authors.initials: FA
authors.lastname: Mulder
authors.forename: Mikael
authors.initials: M
authors.lastname: Akke
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Bodenhausen
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D008954:Models, Biological; D019906:Nuclear Magnetic Resonance, Biomolecular; D050050:Protein Carbonylation; D011506:Proteins / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D011506:Proteins