从单个混合时间的2D NOESY峰强度矩阵求取核间距

提出了从单个混合时间的2D NOESY峰强度或混合系数矩阵直接求取核间距的新方法。该方法分成二步进行。第一步采用规范化2D NOESY峰强度或对称化混合系数矩阵来计算对称化核交叉弛豫速率矩阵。其优点是计算过程简单且普适。第二步直接用对称化核交叉弛豫速率来求取核间距。该过程考虑到分子内部运动的贡献。本文方法是自治的,只要能测出单个混合时间的2D NOESY峰强度或混合系数矩阵即可直接求出自旋系统的核间距了。

INTERNUCLEAR DISTANCE DETERMINATION FROM A 2D NOESY PEAK INTENSITY MATRIX WITH A SINGLE MIXING TIME

A new method is proposed to determine internuclear distances from a 2D NOESY peak intensity or mixing coefficient matrix with a single mixing time. This method is carried out at two stages. At the first stage the symmetrized matrix of nuclear cross relaxation rate is obtained from the regularized 2D NOESY peak intensity or symmetrized mixing coefficient matrix. The calculation in the procedure is quite simple and general. At the second stage the internuclear distances can be extracted directly from the symmetrized nuclear cross relaxation rates and in the course of internuclear distance calculation the internal motion of molecules has been considered. This new method is self-consistent and internuclear distances in spin systems can be determined solely from a 2D NOESY peak intensity or mixing coefficient matrix with a single mixing time.