烯酸碳酸酶对冷适应活性的结构机制
Matthew J McLeod1, Shauhin Yazdani1, Sarah A E Barwell1
1Department of Biology, University of Waterloo, Waterloo, Ontario, Canada.
Protein science : a publication of the Protein Society
|October 16, 2025
概括
酶通过结构变化适应低温,从而降低效率. 这项研究揭示了心理友好性酶,如GTP依赖的酸基因酶 (PEPCK) 如何改变活性位点循环以适应寒冷,从而影响酶动力学.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 酶动力学 酶动力学
背景情况:
- 酶的功能取决于温度,有机体进化酶以优化其生长温度.
- 虽然热稳定性已被理解,但对寒冷 (心理) 的动态适应机制不太清楚.
- 依赖GTP的基酸碳酸酶 (PEPCK) 是一种对代谢途径至关重要的动态酶.
研究的目的:
- 研究酶中冷适应的基础结构和运动机制.
- 为了比较心理友好的PEPCK与其中性友好的对应物之间的结构和动力学.
- 了解酶结构如何与低温下功能的关系.
主要方法:
- 心理友好性和中性友好性PEPCK的运动特征.
- 确定与基板/仿真物结合的心理友好PEPCK的X射线晶体结构.
- 心理友好型和中性友好型PEPCK变体之间的比较结构分析.
主要成果:
- 心理友好的PEPCK显示了较低的催化效率 (kcat/KM) 和降低的最佳温度 (Topt).
- 结构分析显示了心理友好性酶的活性位点 Ω-循环中的替代.
- 这些替代物可能会增加循环排序的性成本,并降低性稳定,阻碍活跃站点关闭.
结论:
- 在 Ω 循环中的特定结构变化为酶催化过程中的冷适应提供了机械基础.
- 这些发现将结构特征与心理友好酶的改变动态行为联系起来.
- 了解酶的冷适应可以为在低温下运行的生物催化剂提供蛋白质工程的信息.
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