NMR snapshots of a fluctuating protein structure: Ubiquitin at 30 bar-3 kbar
NMR snapshots of a fluctuating protein structure: Ubiquitin at 30 bar-3 kbar
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DOI：
10.1016/j.jmb.2005.01.052
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发表时间：
2005-03-25
影响因子：
5.6
通讯作者：
Akasaka, K
中科院分区：
文献类型：
--
作者：
Kitahara, R;Yokoyama, S;Akasaka, K
构象波动在蛋白质功能中起着关键作用，但我们对相关的结构变化知之甚少。在这里，我们提出了一种在原子水平上阐明蛋白质分子在溶液中经历构象涨落时的大规模形状变化的一般方法。该方法利用构象和偏摩尔体积之间的密切关系，确定了三维技术，利用NOE距离和扭角约束来生成平均坐标。泛素(20℃，pH 4.6)被选为第一个目标，其结构是在30bar和3kbar下确定的，给出了原子分辨率下波动的蛋白质结构的“核磁共振快照”。结果表明，螺旋以-gt；3埃上下摆动，同时C-末端片段重新定位，提供了适合酶识别的“开放”构象。自旋驰豫分析表明，这种起伏发生在10微秒的时间范围内，“闭-开”和“开-闭”的激活体积分别为-4.2(+/-3.2)和18.5(+/-3.0)毫升/摩尔。(C)2005爱思唯尔有限公司。保留所有权利。
Conformational fluctuation plays a key role in protein function, but we know little about the associated structural changes. Here we present a general method for elucidating, at the atomic level, a large-scale shape change of a protein molecule in solution undergoing conformational fluctuation. The method utilizes the intimate relationship between conformation and partial molar volume and determines three-dimensional technique, whereby NOE distance and torsion angle constraints are used to create average coordinates. Ubiquitin (pH 4.6 at 20 degrees C) was chosen as the first target, for which structures were determined at 30 bar and at 3 kbar, giving "NMR snapshots" of a fluctuating protein structure at atomic resolution. The result reveals that the helix swings in and out by > 3 angstrom with a simultaneous reorientation of the C-terminal segment, providing an "open" conformer suitable for enzyme recognition. Spin relaxation analysis indicates that this fluctuation occurs in the ten microsecond time range with activation volumes -4.2(+/- 3.2) and 18.5(+/- 3.0) ml/mol for the "closed-to-open" and the "open-to-closed" transitions, respectively. (c) 2005 Elsevier Ltd. All rights reserved.