通过祖先序列重建研究的酶低温适应的洞察力
Shuang Cui1, Subrata Dasgupta2, Sota Yagi1,2
1Faculty of Human Sciences, Waseda University, Tokorozawa, Japan.
Protein science : a publication of the Protein Society
|February 19, 2025
概括
酶从高温向低温的适应进化. 祖先序列重建确定了三种关键氨基酸替代在3-异甲酸脱酶 (IPMDHs) 中,通过减少激活能量来增强低温活性.
科学领域:
- 进化生物学是进化的生物学.
- 生物化学 生化学
- 分子进化是分子进化的过程.
背景情况:
- 酶在数十亿年的时间里进化,适应不断变化的环境条件.
- 早期有机体可能居住在高温环境中,拥有热友性酶.
- 据认为,现代酶 (中性和精神性) 在进化过程中适应了较低的温度.
研究的目的:
- 分析酶低温适应的进化过程.
- 为了确定特定的氨基酸残留物,负责在较低的温度下改变催化性能.
- 了解酶适应不断变化的热环境的基础分子机制.
主要方法:
- 对3-异甲酸脱酶 (IPMDHs) 的祖先序列重建.
- 11种连接祖先和现存酶的进化中间体的表征.
- 位点定向突变发生和比较序列分析.
- 对祖先酶结构的分子动力学模拟.
主要成果:
- 重建的祖先IPMDH在高温下表现出高温稳定性和活性,在低温下表现出适度的活动.
- 在两个进化中间体之间发生了催化性质的显著转变.
- 确定了三种关键的氨基酸替代物,可以增强低温催化活性.
- 这些替代物减少了催化作用的激活能量,但没有显著影响热稳定性.
结论:
- 祖先序列重建是一种强大的工具,用于识别对酶适应低温至关重要的残留物.
- 特定的氨基酸替代可以通过减少激活能量,在低温下增强酶活性.
- 进化途径揭示了酶如何适应不断变化的热环境,以IPMDH从高温到低温的适应为例.
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