将蛋白质-水接口连接到活性位点循环和催化基的热导体的识别
Emily J Thompson1,2, Adhayana Paul1,2, Anthony T Iavarone1,2
1Department of Chemistry, University of California, Berkeley, California 94720, United States.
Journal of the American Chemical Society
|January 4, 2021
概括
蛋白质的移动性对于酶催化是至关重要的. 修改酵母化物
科学领域:
- 生物化学
- 酶动力学
- 蛋白质动力学
背景情况:
- 酵母酶是一种具有TIM桶域的保存酶.
- 蛋白质的移动性会影响酶催化和化学反应.
- 了解蛋白质运动与酶功能的关系是关键.
研究的目的:
- 研究蛋白质流动性在酵母酶催化中的作用.
- 检查特定位点突变如何影响酶的灵活性和活性.
- 将蛋白质动态与酶超级家族中的化学反应性联系起来.
主要方法:
- 局部定向的突变生成以产生受阻的变体 (例如,Leu343Ala).
- 酶动力学测定包括pH速率概况和同位素效应.
- 交换质谱 (HDX-MS) 来绘制蛋白质灵活性变化.
主要成果:
- 在 Leu343 的突变改变了侧链的疏水性,影响了催化基 pKa.
- 确定速率的质子抽象保持不变,由类似的同位素效应表明.
- 突变诱导了蛋白质灵活性的局部变化,影响了活性位点循环的动态.
- 活动和激活能量对侧链体积呈现不连续的反应.
结论:
- 蛋白质的移动性,特别是在特定的网络中,对于高效的酶催化是至关重要的.
- 长距离,溶剂可访问的网络在调整反应物相互作用中发挥作用.
- 选择性蛋白运动是酶的催化机制的组成部分.
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