MAIN-CHAIN-DIRECTED STRATEGY FOR THE ASSIGNMENT OF H-1-NMR SPECTRA OF PROTEINS
MAIN-CHAIN-DIRECTED STRATEGY FOR THE ASSIGNMENT OF H-1-NMR SPECTRA OF PROTEINS
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DOI：
10.1021/bi00393a001
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发表时间：
1987-09-22
期刊：
影响因子：
2.9
通讯作者：
WAND, AJ
中科院分区：
文献类型：
--
作者：
ENGLANDER, SW;WAND, AJ
摘要：描述了一种蛋白质二维核磁共振波谱共振的分配策略。该方法着重于利用二维核奥氏效应（NOE）实验分析质子间的穿越空间关系。算法中使用的NOE模式来源于对21种蛋白质高分辨率晶体结构中观察到的短质子-质子距离组合的统计分析。首先寻找具有高可靠性的真正主链NH-CaH-C^ H/-耦合单元。然后，通过识别预定义的NOE连接模式，将蛋白质的许多主链单元置于适当的并置位置。为了发现这些连通性，我们按照规定的顺序对二维NOE谱进行了检查，以寻找螺旋、片状、旋转和延伸链等不同NOE模式的特征。最后，对一些氨基酸侧链类型的识别将发现的二级结构元素置于多肽序列中。与序列分配方法不同，主链定向策略不依赖于识别/-相关光谱中的许多侧链自旋系统的艰巨任务，分配过程一般不是与多肽链顺序的，规定的连接模式是循环的而不是线性的。后一种特性避免了分析中模棱两可的分支点，并对每个前进步骤施加了内部确认性。二维NMR1技术的发展现在使得它可以解析小到中等大小蛋白质中的所有质子共振，从而在原则上解锁了核磁共振方法在质子解析水平上对溶液中蛋白质的结构和功能研究的固有分析能力。然而，在将这些方法应用于任何给定的蛋白质之前，首先有必要将各种共振分配给它们的母质子。本工作由NIH研究基金AM 31847 （SWE）和GM 35940 (AJW)， NIH基金CA 06927和RR 05539，皮尤纪念信托基金的资助，Marie Z. Cole Montrose的奖励，宾夕法尼亚州联邦授予癌症研究所的拨款，以及仪器补助金RR-02497 （NIH）和DMB 84-13986 （NSF）支持。*请在癌症研究所给作者写信
Revised Manuscript Received July 21, 1987 abstract: A strategy for assigning the resonances in two-dimensional (2D) NMR spectra of proteins is described. The method emphasizes the analysis of through-space relationships between protons by use of the two-dimensional nuclear Overhauser effect (NOE) experiment. NOE patterns used in the algorithm were derived from a statistical analysis of the combinations of short proton-proton distances observed in the high-resolution crystal structures of 21 proteins. One starts with a search for authentic main-chain NH-CaH-C^ H/-coupled units, which can be found with high reliability. The many main-chain units of a protein are then placed in their proper juxtaposition by recognition of predefined NOE connectivity patterns. To discover these connectivities, the 2D NOE spectrum is examined, in a prescribed order, for the distinct NOE patterns characteristic of helices, sheets, turns, and extended chain. Finally, the recognition of a few amino acid side-chain typesplaces the discovered secondary structure elements within the polypeptide sequence. Unlike the sequential assignment approach, the main-chain-directed strategy does not rely on the difficult task of recognizing many side-chain spinsystems in/-correlated spectra, the assignment process is not in general sequential with the polypeptide chain, and the prescribed connectivity patterns are cyclic rather than linear. The latter characteristic avoids ambiguous branch points in the analysis and imposes an internally confirmatory property on each forward step. e development of two-dimensional NMR1 techniques now makes it possible to resolve essentially all the proton resonances in small to moderate sized proteins and thus unlocks, in principle, the inherent analytic power of NMR methods for structural and functional studies of proteins in solution at a proton resolved level. Before these methods can be applied to any given protein, however, it is first necessary to assign the various resonances to their parent protons. The method of sequential assignment, described by Wüthrich and co-f This work was supported by NIH Research Grants AM 31847 (SWE) and GM 35940 (AJW), by NIH Grants CA 06927 and RR 05539, by a grant from thePew Memorial Trust, by an award from Marie Z. Cole Montrose, by an appropriation from the Commonwealth of Pennsylvania awarded to the Institute for Cancer Research, and by Instrumentation Grants RR-02497 (NIH) and DMB 84-13986 (NSF).* Address correspondence to this author at the Institute for Cancer