Reif B, Diener A, Hennig M, Maurer M, Griesinger C
Institut für Organische Chemie, Universität Frankfurt, Marie-Curie-Strasse 11, Frankfurt, D-60439, Germany.
J Magn Reson. 2000 Mar;143(1):45-68. doi: 10.1006/jmre.1999.1980.
Theory,experimental aspects, and use in structure calculation of cross-correlated relaxation rates measured on zero- and double-quantum coherences in liquid state NMR are presented. The relative size of the interaction depends on the projection angle between the two tensorial interactions. The tensorial interaction can be either a dipolar interaction or a chemical shift anisotropy relaxation mechanism (CSA). Effects of additional sources of relaxation on the cross-correlated relaxation rates are analyzed. Also, an easy-to-use formalism is given to manipulate different cross-correlated relaxation interactions. The application addresses measurement of the backbone angle psi in a protein by measuring dipole((15)N-(1)H)-dipole((13)C(alpha)-(1)H(alpha)) and CSA((15)N)-dipole((13)C(alpha)-(1)H(alpha)) cross-correlated relaxation rates. It is shown that ambiguities due to the 3 cos(2)θ-1 dependence of one cross-correlated relaxation rate can be overcome by measuring additional cross-correlated relaxation rates. The use of cross-correlated relaxation rates is demonstrated in structure calculations.
本文介绍了液态核磁共振中零量子和双量子相干测量的交叉相关弛豫率的理论、实验方面及其在结构计算中的应用。相互作用的相对大小取决于两个张量相互作用之间的投影角。张量相互作用可以是偶极相互作用或化学位移各向异性弛豫机制（CSA）。分析了其他弛豫源对交叉相关弛豫率的影响。此外，还给出了一种易于使用的形式来处理不同的交叉相关弛豫相互作用。该应用通过测量偶极（（15）N-（1）H）-偶极（（13）Cα-（1）Hα）和CSA（（15）N）-偶极（（13）Cα-（1）Hα）交叉相关弛豫率来测量蛋白质中的主链角ψ。结果表明，通过测量额外的交叉相关弛豫率，可以克服由于一个交叉相关弛豫率的3cos（2）θ-1依赖性引起的模糊性。交叉相关弛豫率在结构计算中的应用得到了证明。
