Sezer Deniz, Prandolini M J, Prisner Thomas F
Institut für Physikalische und Theoretische Chemie, J. W. Goethe-Universität, 60438 Frankfurt am Main, Germany.
Phys Chem Chem Phys. 2009 Aug 21;11(31):6626-37. doi: 10.1039/b905709a. Epub 2009 Jul 6.
The magnetic resonance signal obtained from nuclear spins is strongly affected by the presence of nearby electronic spins. This effect finds application in biomedical imaging and structural characterization of large biomolecules. In many of these applications nitroxide free radicals are widely used due to their non-toxicity and versatility as site-specific spin labels. We perform molecular dynamics simulations to study the electron-nucleus interaction of the nitroxide radical TEMPOL and water in atomistic detail. Correlation functions corresponding to the dipolar and scalar spin-spin couplings are computed from the simulations. The dynamic nuclear polarization coupling factors deduced from these correlation functions are in good agreement with experiment over a broad range of magnetic field strengths. The present approach can be applied to study solute-solvent interactions in general, and to characterize solvent dynamics on the surfaces of proteins or other spin-labeled biomolecules in particular.
从核自旋获得的磁共振信号会受到附近电子自旋存在的强烈影响。这种效应在生物医学成像和大型生物分子的结构表征中得到应用。在许多此类应用中，氮氧化物自由基因其无毒且作为位点特异性自旋标记具有通用性而被广泛使用。我们进行分子动力学模拟，以原子级细节研究氮氧化物自由基TEMPOL与水之间的电子 - 核相互作用。从模拟中计算出与偶极和标量自旋 - 自旋耦合相对应的相关函数。从这些相关函数推导出的动态核极化耦合因子在很宽的磁场强度范围内与实验结果吻合良好。本方法一般可用于研究溶质 - 溶剂相互作用，尤其可用于表征蛋白质或其他自旋标记生物分子表面的溶剂动力学。
