A phase cycle scheme that significantly suppresses offset-dependent artifacts in the R2-CPMG 15N relaxation experiment

被引:74
作者
Yip, GNB
Zuiderweg, ERP
机构
[1] Univ Michigan, Dept Chem, Div Biophys Res, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Dept Biophys, Div Biophys Res, Ann Arbor, MI 48109 USA
[3] Univ Michigan, Dept Biol Chem, Div Biophys Res, Ann Arbor, MI 48109 USA
关键词
CPMG; offset dependent artifacts; transverse (T-2) relaxation; phase cycle; relative accuracy; bloch simulations; relaxation dispersion;
D O I
10.1016/j.jmr.2004.06.021
中图分类号
Q5 [生物化学];
学科分类号
071010 ; 081704 ;
摘要
R-2-CPMG N-15 relaxation experiments form the basis of NMR dynamics measurements, both for analysis of nano-pico second dynamics and milli-micro second dynamics (kinetics). It has been known for some time that in the practical limit of finite pulse widths, which becomes acute when using cryogenic probes, systematic errors in the apparent R-2 relaxation behavior occur for spins far off-resonance from the RE carrier. Inaccurate measurement of R-2 rates propagates into quantitative models such as model-free relaxation analysis, rotational diffusion tensor analysis, and relaxation dispersion. The root of the problem stems from evolution of the magnetization vectors out of the XY-plane, both during the pulses as well as between the pulses. These deviations vary as a function of pulse length, number of applied CPMG pulses, and CPMG inter-pulse delay. Herein, we analyze these effects in detail with experimentation, numerical simulations, and analytical equations. Our work suggests a surprisingly simple change in the phase progression of the CPMG pulses, which leads to a remarkable improvement in performance. First, the applicability range of the CPMG experiment is increased by a factor of two in spectral width; second, the dynamical/kinetic processes that can be assessed are significantly extended towards the slower time scale; finally, the robustness of the relaxation dispersion experiments is greatly improved. (C) 2004 Elsevier Inc. All rights reserved.
引用
收藏
页码:25 / 36
页数:12
相关论文
共 29 条
[1]  
BLOCH F, 1946, PHYS REV, V70, P460, DOI 10.1103/PhysRev.70.460
[2]   May the driving force be with you - whatever it is [J].
Cavanagh, J ;
Akke, M .
NATURE STRUCTURAL BIOLOGY, 2000, 7 (01) :11-13
[3]   Removal of systematic errors associated with off-resonance oscillations in T-2 measurements [J].
Czisch, M ;
King, GC ;
Ross, A .
JOURNAL OF MAGNETIC RESONANCE, 1997, 126 (01) :154-157
[4]   Protein NMR relaxation: theory, applications and outlook [J].
Fischer, MWF ;
Majumdar, A ;
Zuiderweg, ERP .
PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY, 1998, 33 :207-272
[5]   Disulfide bond isomerization in basic pancreatic trypsin inhibitor: Multisite chemical exchange quantified by CPMG relaxation dispersion and chemical shift modeling [J].
Grey, MJ ;
Wang, CY ;
Palmer, AG .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2003, 125 (47) :14324-14335
[6]   Protein dynamics from NMR [J].
Ishima, R ;
Torchia, DA .
NATURE STRUCTURAL BIOLOGY, 2000, 7 (09) :740-743
[7]   Carbonyl carbon transverse relaxation dispersion measurements and ms-μs timescale motion in a protein hydrogen bond network [J].
Ishima, R ;
Baber, J ;
Louis, JM ;
Torchia, DA .
JOURNAL OF BIOMOLECULAR NMR, 2004, 29 (02) :187-198
[8]   Extending the range of amide proton relaxation dispersion experiments in proteins using a constant-time relaxation-compensated CPMG approach [J].
Ishima, R ;
Torchia, DA .
JOURNAL OF BIOMOLECULAR NMR, 2003, 25 (03) :243-248
[9]   Propagation of experimental uncertainties using the Lipari-Szabo model-free analysis of protein dynamics [J].
Jin, DQ ;
Andrec, M ;
Montelione, GT ;
Levy, RM .
JOURNAL OF BIOMOLECULAR NMR, 1998, 12 (04) :471-492
[10]   Protein dynamics from NMR [J].
Kay, LE .
NATURE STRUCTURAL BIOLOGY, 1998, 5 (Suppl 7) :513-517