title: Cross-correlated relaxation enhanced 1H[bond]13C NMR spectroscopy of methyl groups in very high molecular weight proteins and protein complexes.
abstract: A comparison of HSQC and HMQC pulse schemes for recording (1)H[bond](13)C correlation maps of protonated methyl groups in highly deuterated proteins is presented. It is shown that HMQC correlation maps can be as much as a factor of 3 more sensitive than their HSQC counterparts and that the sensitivity gains result from a TROSY effect that involves cancellation of intra-methyl dipolar relaxation interactions. (1)H[bond](13)C correlation spectra are recorded on U-[(15)N,(2)H], Ile delta 1-[(13)C,(1)H] samples of (i) malate synthase G, a 723 residue protein, at 37 and 5 degrees C, and of (ii) the protease ClpP, comprising 14 identical subunits, each with 193 residues (305 kDa), at 5 degrees C. The high quality of HMQC spectra obtained in short measuring times strongly suggests that methyl groups will be useful probes of structure and dynamics in supramolecular complexes.
authors.affiliation: Protein Engineering Network Centers of Excellence and Department of Medical Genetics, The University of Toronto, Toronto, Ontario, Canada M5S 1A8.
authors.forename: Vitali
authors.initials: V
authors.lastname: Tugarinov
authors.forename: Peter M
authors.initials: PM
authors.lastname: Hwang
authors.forename: Jason E
authors.initials: JE
authors.lastname: Ollerenshaw
authors.forename: Lewis E
authors.initials: LE
authors.lastname: Kay
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry*; D002247:Carbon Isotopes; D049071:Endopeptidase Clp; D008292:Malate Synthase / Q000737:chemistry*; D008956:Models, Chemical; D008970:Molecular Weight; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011522:Protons; D012697:Serine Endopeptidases / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D002247:Carbon Isotopes; D011522:Protons; D008292:Malate Synthase; D012697:Serine Endopeptidases; D049071:Endopeptidase Clp; D000251:Adenosine Triphosphatases