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催化His-loop灵活性驱动了高热友雌激酶EstE1的高活性,同时保持了结构稳定性

Khang Nguyen^1,2, ChangWoo Lee^1,2

¹Department of Biomedical Science, Daegu University, Gyeongsan, South Korea.

Microbiology spectrum

|August 14, 2025

概括

超热友性雌激酶EstE1通过灵活的催化His循环实现高活性,与其依赖循环稳定性的中友性对应物rPPE不同. 调节循环的灵活性为设计稳定,高性能热友酶提供了洞察力.

科学领域:

生物化学生物化学
酶学是一种酶学.
蛋白质工程是指蛋白质工程.

背景情况:

乙酶是催化乙键的水解和形成的关键酶,通常利用一种催化Ser-His-Asp三合体.
超热友性雌激酶EstE1尽管结构刚硬,但表现出高活性,与其半热友性对应物rPPE.PPE形成鲜明对比.
研究了催化His循环的灵活性,作为EstE1和rPPE中酶活性的关键调节器.

研究的目的:

为了研究催化His循环如何影响超热友性雌激酶EstE1及其中友性对应物rPPE中的酶活性.
通过向突变发生,探索热友酶中高催化活性的结构基础.
为工程热友性酶提供洞察力,以提高性能和稳定性.

主要方法:

用于引入特定氨基酸替代物在EstE1 (Gly282到Asn/Gln) 和rPPE (Asp287到Gly/Glu) 中,采用了位点定向的突变发生.
进行了酶活性测定,以量化催化性能.
使用光谱和烯胺火法来评估蛋白质结构,循环灵活性和稳定性.

主要成果:

在EstE1 (G282N,G282Q) 中的突变促进或破坏了His循环中的结合,减少了酶活性.
EstE1的G282N突变体表现出增加的刚性和依赖时间的活动损失,而G282Q表现出比野生类型更大的灵活性.
在rPPE中,D287G通过增加循环灵活性增强了活性,而D287E通过加强键增强了稳定性和基质亲和力.

结论:

在 EstE1 中的 Gly282 促进了对于高温活动至关重要的 His-loop 灵活性,而 rPPE 使用了 His-loop 键,以牺牲活动的稳定性.
通过向突变调节His-loop的灵活性和稳定性,为酶工程提供了一个策略.
了解这些独特的机制为设计热友性酶提供了一个框架,以提高催化效率和结构完整性.

关键词:

活动现场动态活动现场动态催化他的循环.形状的灵活性形状的灵活性埃斯特拉酶的使用方法温度适应温度适应热稳定性的热稳定性

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