Nevzorov Alexander A, Opella Stanley J
Department of Chemistry, University of California at San Diego, 9500 Gilman Drive, 92093-0307, La Jolla, CA, USA.
J Magn Reson. 2003 Jan;160(1):33-9. doi: 10.1016/s1090-7807(02)00138-6.
An algorithm for fitting protein structures to PISEMA spectra is described, and its application to helical proteins in aligned samples is demonstrated using both simulated and experimental results. The formulation of the algorithm in terms of rotation operators yields compact recursion relations that provide a fast and effective way of obtaining peptide plane orientations from chemical and torsion angle constraints. The algorithm in combination with experimental solid-state NMR data results in a method for determining the backbone structures of proteins, since it yields the orientation of a helix as a whole, including its tilt and twist angles, and describes kinks and curves with atomic resolution. Although the algorithm can be applied in an "assignment-free" manner to spectra of uniformly labeled proteins, the precision of the structural fitting is improved by the addition of assignment information, for example the identification of resonances by residue type from spectra of selectively labeled proteins.
本文描述了一种将蛋白质结构拟合到PISEMA光谱的算法，并通过模拟和实验结果展示了其在对齐样本中螺旋蛋白质的应用。该算法基于旋转算子的公式产生了紧凑的递归关系，提供了一种从化学和扭转角约束中快速有效地获得肽平面取向的方法。该算法与实验固态核磁共振数据相结合，形成了一种确定蛋白质主链结构的方法，因为它能给出整个螺旋的取向，包括其倾斜角和扭转角，并以原子分辨率描述扭结和弯曲。虽然该算法可以以“无分配”的方式应用于均匀标记蛋白质的光谱，但通过添加分配信息，例如从选择性标记蛋白质的光谱中按残基类型识别共振，可以提高结构拟合的精度。
