Structure and dynamics of Pin1 during catalysis by NMR
Structure and dynamics of Pin1 during catalysis by NMR
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DOI：
10.1016/j.jmb.2007.01.049
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发表时间：
2007-04-13
影响因子：
5.6
通讯作者：
Kern, Dorothee
中科院分区：
文献类型：
--
作者：
Labeikovsky, Wladimir;Eisenmesser, Elan Z.;Kern, Dorothee
内部酶运动和催化之间的联系知之甚少。在微秒到毫秒的时间尺度上的相关运动可能对酶的功能至关重要。我们的特点是在自由状态和催化过程中的肽基脯氨酰异构酶（Pin 1）催化结构域的骨架动力学。Pin 1是小蛋白家族的脯氨酰异构酶，特异性催化磷酸化Ser/Thr-Pro肽键的异构化。Pin 1已被证明是细胞周期进程所必需的，并与神经元tau蛋白相互作用，抑制其聚集成纤维缠结，如在阿尔茨海默病中发现的。N-15弛豫色散测量Pin 1在催化过程中揭示了在微秒时间尺度的构象交换过程。一个子集的活性位点残基进行动力学相似的交换过程，即使在没有一个基板，这表明该地区已经是“启动”的催化。此外，翻转酶的结构数据，通过分子间和分子内的核Overhauser增强。这种分析连同表征的构象交换的底物浓度依赖性允许区分的酶活性位点的区域，主要受底物结合与底物异构化。这些数据共同提出了Pin 1催化反应轨迹的模型。(c)2007爱思唯尔有限公司保留所有权利。
The link between internal enzyme motions and catalysis is poorly understood. Correlated motions in the microsecond-to-millisecond time-scale may be critical for enzyme function. We have characterized the backbone dynamics of the peptidylprolyl isomerase (Pin1) catalytic domain in the free state and during catalysis. Pin1 is a prolyl isomerase of the parvulin family and specifically catalyzes the isomerization of phosphorylated Ser/Thr-Pro peptide bonds. Pin1 has been shown to be essential for cell-cycle progression and to interact with the neuronal tau protein inhibiting its aggregation into fibrillar tangles as found in Alzheimer's disease. N-15 relaxation dispersion measurements performed on Pin1 during catalysis reveal conformational exchange processes in the microsecond timescale. A subset of active site residues undergo kinetically similar exchange processes even in the absence of a substrate, suggesting that this area is already "primed" for catalysis. Furthermore, structural data of the turning-over enzyme were obtained through inter- and intramolecular nuclear Overhauser enhancements. This analysis together with a characterization of the substrate concentration dependence of the conformational exchange allowed the distinguishing of regions of the enzyme active site that are affected primarily by substrate binding versus substrate isomerization. Together these data suggest a model for the reaction trajectory of Pin1 catalysis. (c) 2007 Elsevier Ltd. All rights reserved.