Schmieder P, Stern A S, Wagner G, Hoch J C
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.
J Biomol NMR. 1993 Sep;3(5):569-76. doi: 10.1007/BF00174610.
Nonlinear sampling along the t1 dimension is applied to COSY-type spectra. The sine dependence of the time domain signals for the cross peaks is matched by a nonlinear sampling scheme that samples most densely around the maximum of the sine function. Data are processed by maximum entropy reconstruction, using a modified implementation of the 'Cambridge' algorithm of Skilling and Bryan. The procedure is demonstrated for P.E. COSY spectra recorded on a cyclic hexapeptide and on a 126-residue domain of the protein villin. The number of t1 values in the nonlinearly sampled experiments was reduced by a factor of four compared to linear sampling. The sensitivity and resolution of the resulting spectra are comparable to those achieved by conventional methods. The method described can thus significantly reduce the measuring time for COSY-type spectra.
沿t1维度的非线性采样应用于COSY型谱图。通过非线性采样方案匹配交叉峰时域信号的正弦依赖性，该方案在正弦函数最大值附近进行最密集采样。数据采用最大熵重建法处理，使用了Skilling和Bryan的“剑桥”算法的改进实现。该过程在环六肽和蛋白质绒毛蛋白的126个残基结构域上记录的P.E. COSY谱图中得到了验证。与线性采样相比，非线性采样实验中t1值的数量减少了四倍。所得谱图的灵敏度和分辨率与传统方法相当。因此，所描述的方法可以显著减少COSY型谱图的测量时间。
