LOCAL PERTURBATIONS BY LIGAND-BINDING OF HYDROGEN-DEUTERIUM EXCHANGE KINETICS IN A 4-HELIX BUNDLE PROTEIN, ACYL-COENZYME-A BINDING-PROTEIN (ACBP)
LOCAL PERTURBATIONS BY LIGAND-BINDING OF HYDROGEN-DEUTERIUM EXCHANGE KINETICS IN A 4-HELIX BUNDLE PROTEIN, ACYL-COENZYME-A BINDING-PROTEIN (ACBP)
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DOI：
10.1006/jmbi.1995.0409
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发表时间：
1995-07-28
影响因子：
5.6
通讯作者：
POULSEN, FM
中科院分区：
文献类型：
--
作者：
KRAGELUND, BB;KNUDSEN, J;POULSEN, FM
本文用核磁共振波谱法研究了四螺旋束蛋白酰基辅酶A结合蛋白中单个酰胺的酰胺氢交换动力学。（-2.5至10）（-6.5）S-1在pH6.65的游离蛋白质和配体-蛋白质复合物中的结合作用，对个别汇率进行了分析。交换动力学和已知的酰基辅酶A结合蛋白的三维结构的个别酰胺的结构特性之间的具体相关性进行了检查。此外，已经进行了分析，比较从棕榈酰辅酶A和酰基辅酶A结合蛋白的复合物的三维结构已知的蛋白质-配体相互作用的结构扰动与配体诱导的酰胺交换动力学扰动。最后，配位体引起的氢交换扰动已被比较与N-15弛豫。结果表明，酰基辅酶A结合蛋白各位点的氢交换动力学主要由局部结构特征决定，配体结合主要引起蛋白与配体相互作用位点的变化;它们意味着由连接引起的交换动力学的扰动可以是，如在一个实施例中，通过形成氢键而引起的交换前平衡的局部稳定化，或者如在几个实施例中看到的，导致交换前平衡的打开和关闭过程的动态过程的减少。结果似乎没有表明最终化学交换步骤的速率发生变化。(C)1995年学术出版社
Amide hydrogen exchange kinetics of the individual amides in a four-helix bundle protein, acyl-coenzyme A binding protein, have been studied by nuclear magnetic resonance spectroscopy The kinetics of amides with exchange rate constants in the range of 10(-2.5) to 10(-6.5) S-1 at pH 6.65 in free protein and the ligand-protein complex have been measured, and the effect of binding the ligand, palmitoyl-coenzyme A, on individual exchange rates has been analysed. Specific correlations between exchange kinetics and the structural properties of the individual amides known from the three-dimensional structure of acyl-coenzyme A binding protein have been examined. Furthermore, an analysis has been performed comparing the structural perturbations of the protein-ligand interactions known from the three dimensional structure of the complex of palmitoyl-coenzyme A and acyl-coenzyme A binding protein with the ligand-induced perturbations on the amides exchange kinetics. Finally, the ligand-induced perturbations on hydrogen exchange have been compared with those on N-15 relaxation. The results suggest that hydrogen exchange kinetics in the individual sites of acyl-coenzyme A binding protein are primarily determined by local structural features they show that ligand binding gives rise mainly to changes localized at the sites of interaction between protein and ligand; they imply that the perturbation of exchange kinetics caused by ligation can be either, as in one example a local stabilisation of the pre-exchange equilibrium induced by formation of a hydrogen bond, or as seen here in several examples a reduction of the dynamic processes that lead to the opening and closing processes of the pre-exchange equilibrium. The results seem not to indicate changes in the rate of the final chemical exchange step. (C) 1995 Academic Press Limited