<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ravindranathan, S</style></author><author><style face="normal" font="default" size="100%">Kim, CH</style></author><author><style face="normal" font="default" size="100%">Bodenhausen, G</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Determination of C-13 CSA tensors: extension of the model-independent approach to an RNA kissing complex undergoing anisotropic rotational diffusion in solution</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Biomolecular NMR</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">anisotropic rotational diffusion</style></keyword><keyword><style  face="normal" font="default" size="100%">chemical shift anisotropy tensors</style></keyword><keyword><style  face="normal" font="default" size="100%">cross-correlation</style></keyword><keyword><style  face="normal" font="default" size="100%">model-independent approach</style></keyword><keyword><style  face="normal" font="default" size="100%">NMR</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">NOV</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">3</style></number><publisher><style face="normal" font="default" size="100%">SPRINGER</style></publisher><pub-location><style face="normal" font="default" size="100%">VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">33</style></volume><pages><style face="normal" font="default" size="100%">163-174</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Chemical shift anisotropy (CSA) tensor parameters have been determined for the protonated carbons of the purine bases in an RNA kissing complex in solution by extending the model-independent approach [Fushman, D., Cowburn, D. (1998) J. Am. Chem. Soc. 120, 7109-7110]. A strategy for determining CSA tensor parameters of heteronuclei in isolated X-H two-spin systems (X = C-13 or N-15) in molecules undergoing anisotropic rotational diffusion is presented. The original method relies on the fact that the ratio kappa(2)=R-2(auto)/R-2(cross) of the transverse auto- and cross-correlated relaxation rates involving the X CSA and the X-H dipolar interaction is independent of parameters related to molecular motion, provided rotational diffusion is isotropic. However, if the overall motion is anisotropic kappa(2) depends on the anisotropy D parallel to/D-perpendicular to of rotational diffusion. In this paper, the field dependence of both kappa(2) and its longitudinal counterpart kappa(1)=R-1(auto)/R-1(cross) are determined. For anisotropic rotational diffusion, our calculations show that the average kappa(av) = 1/2 (kappa(1)+kappa(2)), of the ratios is largely independent of the anisotropy parameter D parallel to/D-perpendicular to. The field dependence of the average ratio kappa(av) may thus be utilized to determine CSA tensor parameters by a generalized model-independent approach in the case of molecules with an overall motion described by an axially symmetric rotational diffusion tensor.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><work-type><style face="normal" font="default" size="100%">Article</style></work-type><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">3.439</style></custom4></record></records></xml>