title: Multiplet-filtered and gradient-selected zero-quantum TROSY experiments for 13C1H3 methyl groups in proteins.
abstract: Multiplet-filtered and gradient-selected heteronuclear zero-quantum coherence (gsHZQC) TROSY experiments are described for measuring (1)H-(13)C correlations for (13)CH(3) methyl groups in proteins. These experiments provide improved suppression of undesirable, broad outer components of the heteronuclear zero-quantum multiplet in medium-sized proteins, or in flexible sites of larger proteins, compared to previously described HZQC sequences (Tugarinov et al. in J Am Chem Soc 126:4921-4925, 2004; Ollerenshaw et al. in J Biomol NMR 33:25-41, 2005). Hahn-echo versions of the gsHZQC experiment also are described for measuring zero- and double-quantum transverse relaxation rate constants for identification of chemical exchange broadening. Application of the proposed pulse sequences to Escherichia coli ribonuclease HI, with a molecular mass of 18 kD, indicates that improved multiplet suppression is obtained without substantial loss of sensitivity.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Columbia University, 630 West 168th Street, New York, NY 10032, USA.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Gill
authors.forename: Arthur G
authors.initials: AG
authors.lastname: Palmer
mesh_terms: D002247:Carbon Isotopes; D004926:Escherichia coli / Q000201:enzymology; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D016914:Ribonuclease H / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D011506:Proteins; D016914:Ribonuclease H; C078856:ribonuclease HI