IDENTIFICATION AND LOCALIZATION OF BOUND INTERNAL WATER IN THE SOLUTION STRUCTURE OF INTERLEUKIN-1-BETA BY HETERONUCLEAR 3-DIMENSIONAL H-1 ROTATING-FRAME OVERHAUSER N-15-H-1 MULTIPLE QUANTUM COHERENCE NMR-SPECTROSCOPY
IDENTIFICATION AND LOCALIZATION OF BOUND INTERNAL WATER IN THE SOLUTION STRUCTURE OF INTERLEUKIN-1-BETA BY HETERONUCLEAR 3-DIMENSIONAL H-1 ROTATING-FRAME OVERHAUSER N-15-H-1 MULTIPLE QUANTUM COHERENCE NMR-SPECTROSCOPY
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DOI：
10.1021/bi00476a004
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发表时间：
1990-06-19
期刊：
影响因子：
2.9
通讯作者：
GRONENBORN, AM
中科院分区：
文献类型：
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作者：
CLORE, GM;BAX, A;GRONENBORN, AM
白介素1 - β溶液结构中结合水分子的存在和位置。利用三维1H旋转框架Overhauser 1H- 15n多重量子相干光谱（roesi - hmqc）对其进行了研究。在本实验中，NH质子与束缚水之间通过空间旋转框架的Overhauser （ROE）相互作用。明显区别于化学交换效应，因为这两个过程的交叉峰是相反的符号。根据直接键合的氮原子的15N化学位移，通过将光谱扩展到第三维，可以使氢质子和水之间的ro的识别变得简单。通过这种方法，除了极少数有限的情况外，所有的问题都阻止了在大蛋白（如白细胞介素1. β）的二维1H-1H ROESY光谱中NH质子和水之间的ROE峰的解释、识别和分配。即广泛的NH化学位移简并和ROE峰被更强的化学交换峰所掩盖，完全被规避了。我们证明了靠近结合水分子的15个氢原子的存在。从对白细胞介素1 - β晶体结构的检查。[Finzel, b.c, Clancy， L. L., Holland， D. R, Muchmore， S. W., Watenpaugh， K. D., and Elinspahr， H. M. (1989) J. Mol.生物学报，209,779-791]，结果可归因于11个水分子参与相互作用，桥接氢键相互作用与主链酰胺和羰基稳定白细胞介素1. β的3倍赝对称拓扑结构。从而构成了溶液中蛋白质结构的一个组成部分。
The presence and location of bound internal water molecules in the solution structure of interleukin 1.beta. have been investigated by means of three-dimensional 1H rotating-frame Overhauser 1H-15N multiple quantum coherence spectroscopy (ROESY-HMQC). In this experiment through-space rotating-frame Overhauser (ROE) interactions between NH protons and bound water separated by .ltoreq.3.5 .ANG. are clearly distinguished from chemical exchange effects, as the cross-peaks for these two processes are of opposite sign. The identification of ROEs between NH protons and water is rendered simple by spreading out the spectrum into a third dimension according to the 15N chemical shift of the directly bonded nitrogen atoms. By this means, the problems that prevent, in all but a very few limited cases, the interpretation, identification, and assignment of ROE peaks between NH protons and water in a 2D 1H-1H ROESY spectrum of a large protein such as interleukin 1.beta., namely, extensive NH chemical shift degeneracy and ROE peaks obscured by much stronger chemical exchange peaks, are completely circumvented. We demonstrate the existence of 15 NH protons that are close to bound water molecules. From an examination of the crystal structure of interleukin 1.beta. [Finzel, B. C., Clancy, L. L., Holland, D. R., Muchmore, S. W., Watenpaugh, K. D., and Elinspahr, H. M. (1989) J. Mol. Biol. 209, 779-791], the results can be attributed to 11 water molecules that are involved in interactions bridging hydrogen-bonding interactions with backbone amide and carbonyl groups which stabilize the 3-fold pseudosymmetric topology of interleukin 1.beta. and thus constitute an integral part of the protein structure in solution.