On the accurate measurement of amide one-bond 15N–1H couplings in proteins: Effects of cross-correlated relaxation, selective pulses and dynamic frequency shifts Export

@article{citeulike:4920677, abstract = {Amide one-bond 15 N– 1 H scalar couplings of 15 N- and [ 15 N, 2 H]-isotopically enriched ubiquitin have been measured with the Quantitative J approach by monitoring NMR signal intensity modulation. Scalar couplings of the non-deuterated protein are in average 0.6 Hz larger than values of deuterated ubiquitin. This deviation is 30 times the error derived from experiment reproducibility. Refocusing dipole/dipole cross-correlated relaxation decreases the discrepancy to 0.1 Hz, suggesting that it likely originates from relaxation interference. Alternatively, the subtraction of J values obtained at different magnetic fields largely reduces the relaxation effects. In contrast, the dynamic frequency shift whose main contribution to 1 J ( 15 N– 1 H) arises from 15 N chemical shielding anisotropy/NH dipole cross-correlation, is not eliminated by refocusing spin evolution under this interaction. Furthermore, the average difference of 1 J ( 15 N– 1 H) values at two magnetic fields closely agrees with the theoretical expected difference in the dynamic frequency shift.}, author = {Alba, E. and Tjandra, N.}, citeulike-article-id = {4920677}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.jmr.2006.08.003}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/S1090780706002461}, doi = {10.1016/j.jmr.2006.08.003}, issn = {10907807}, journal = {Journal of Magnetic Resonance}, keywords = {cross-correlation, j-couplings, nmr-methods, rdc, relaxation}, month = {November}, number = {1}, pages = {160--165}, posted-at = {2009-06-22 02:40:44}, priority = {2}, title = {On the accurate measurement of amide one-bond 15N–1H couplings in proteins: Effects of cross-correlated relaxation, selective pulses and dynamic frequency shifts}, url = {http://dx.doi.org/10.1016/j.jmr.2006.08.003}, volume = {183}, year = {2006} }

TY - JOUR ID - citeulike:4920677 L3 - citeulike-article-id:4920677 N2 - Amide one-bond 15 N– 1 H scalar couplings of 15 N- and [ 15 N, 2 H]-isotopically enriched ubiquitin have been measured with the Quantitative J approach by monitoring NMR signal intensity modulation. Scalar couplings of the non-deuterated protein are in average 0.6 Hz larger than values of deuterated ubiquitin. This deviation is 30 times the error derived from experiment reproducibility. Refocusing dipole/dipole cross-correlated relaxation decreases the discrepancy to 0.1 Hz, suggesting that it likely originates from relaxation interference. Alternatively, the subtraction of J values obtained at different magnetic fields largely reduces the relaxation effects. In contrast, the dynamic frequency shift whose main contribution to 1 J ( 15 N– 1 H) arises from 15 N chemical shielding anisotropy/NH dipole cross-correlation, is not eliminated by refocusing spin evolution under this interaction. Furthermore, the average difference of 1 J ( 15 N– 1 H) values at two magnetic fields closely agrees with the theoretical expected difference in the dynamic frequency shift. IS - 1 JF - Journal of Magnetic Resonance SN - 10907807 EP - 165 TI - On the accurate measurement of amide one-bond 15N–1H couplings in proteins: Effects of cross-correlated relaxation, selective pulses and dynamic frequency shifts VL - 183 SP - 160 KW - cross-correlation KW - j-couplings KW - nmr-methods KW - rdc KW - relaxation AU - Alba, E AU - Tjandra, N PY - 2006/11// UR - http://dx.doi.org/10.1016/j.jmr.2006.08.003 ER -