On the measurement of ¹⁵N-{¹H} nuclear Overhauser effects. 2. Effects of the saturation scheme and water signal suppression.
Measurement of steady-state (15)N-{(1)H} nuclear Overhauser effects forms a cornerstone of most methods to determine protein backbone dynamics from spin-relaxation data, since it is the most reliable probe of very fast motions on the ps-ns timescale. We have, in two previous publications (J. Magn. Reson. 192 (2008) 302-313; J. Am. Chem. Soc. 131 (2009) 6048-6049) reevaluated spin-dynamics during steady-state (or "saturated") and reference experiments, both of which are required to determine the NOE ratio. Here we assess the performance of several windowed and windowless sequences to achieve effective saturation of protons in steady-state experiments. We also evaluate the influence of the residual water signal due to radiation damping on the NOE ratio. We suggest a recipe that allows one to determine steady-state (15)N-{(1)H} NOE's without artifacts and with the highest possible accuracy.
Département de Chimie, Ecole Normale Supérieure and CNRS UMR 7203, Laboratoire des Biomolécules, 24, rue Lhomond, 75231 Paris Cedex 05, France. Fabien.Ferrage@ens.fr
Fabien
F
Ferrage
Amy
A
Reichel
Shibani
S
Battacharya
David
D
Cowburn
Ranajeet
R
Ghose
D000465:Algorithms; D007554:Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009584:Nitrogen; D009587:Nitrogen Isotopes; D011522:Protons; D011827:Radiation; D014867:Water / Q000737:chemistry*
D007554:Isotopes; D009587:Nitrogen Isotopes; D011522:Protons; D014867:Water; D009584:Nitrogen