来自Thermococcus sibiricus的高热性L-阿斯巴拉金酶及其双重突变的增加活性:对基质特异性和结构的洞察
Maria V Dumina1, Dmitry D Zhdanov2, Alexander V Veselovsky2
1Federal Research Center "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Moscow 117312, Russia.
International journal of molecular sciences
|June 26, 2025
概括
这项研究揭示,来自Thermococcus sibiricus的高热友性L-asparaginase (L-ASNase) 的突变增强了其活性并改变了基质特异性,为改善生物技术应用提供了潜在的潜力.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 结构生物学 结构生物学
背景情况:
- 通过减少烯胺,L-氨酸酶 (L-ASNase) 对癌症治疗和食品安全至关重要.
- 来自Thermococcus sibiricus (TsAI) 的高热性L-ASNase由于其活性和稳定性,对生物技术具有前景.
研究的目的:
- 调查 TsAI 的结构功能关系.
- 将TsAI与表现出增强活动的双重突变 (TsAID54G/T56Q) 进行比较.
- 了解突变对基质特异性和酶功能的影响.
主要方法:
- 酶动力学和基质特异性测试.
- 用于结构特征的X射线晶体学 (1.9 Å分辨率).
- 分子对接模拟. 分子对接模拟.
主要成果:
- TsAI和TsAID54G/T56Q显示出高的D-阿斯巴拉金活性 (分别为L-阿斯巴拉金酶活性的62%和21%) 和低的L-氨酸酶协活性 (~5%).
- 与TsAI相比,在突变者中恢复美索菲尔样三元体 (GSQ) 将L-阿斯巴拉金活性增加了一倍.
- 突变增加了活性部位附近的循环灵活性,这对于热ASNase活性至关重要.
- 分子对接表明,D-阿斯巴拉金的导向对于催化是次优的,高温可能会降低L-ASNase的歧视.
结论:
- 结构和生化数据阐明了热-ASNase的功能.
- 获得的洞察力可以指导改进的L-ASNase变体的工程,用于生物技术应用.
- 了解循环流动性和温度效应是酶工程的关键.
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