Cross-correlated relaxation enhanced 1H[bond]13C NMR spectroscopy of methyl groups in very high molecular weight proteins and protein complexes.
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.
Tugarinov
Vitali
V
Protein Engineering Network Centers of Excellence and Department of Medical Genetics, The University of Toronto, Toronto, Ontario, Canada M5S 1A8.
Hwang
Peter M
PM
Ollerenshaw
Jason E
JE
Kay
Lewis E
LE
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
D002247:Carbon Isotopes; D011522:Protons; D008292:Malate Synthase; D012697:Serine Endopeptidases; D049071:Endopeptidase Clp; D000251:Adenosine Triphosphatases