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热力学剖析揭示了DNA聚合酶模板结合,基质结合和外核酶功能

Yaping Sun¹, Wu Lin¹, Kang Fu¹

¹Research Center of Molecular Diagnostics and Sequencing, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518000, China.

International journal of molecular sciences

|December 30, 2025

概括

异热定位热量计揭示了一种新型DNA聚合酶 (SS_01) 的金属离子依赖能量. 这种突变体包含非自然核酸,与Ca2+相比,Mg2+可实现更紧密的结合和高效的催化.

科学领域:

生物化学生物化学
分子生物学分子生物学
酶动力学酶动力学

背景情况:

异热定位热量计 (ITC) 是一种强大的生物物理技术,用于研究酶机制.
DNA聚合酶是参与DNA复制和修复的关键酶.
金属离子在DNA聚合酶的催化活性中起着至关重要的作用.

研究的目的:

为了描述 Phi29突变DNA聚合酶 (SS_01) 的金属离子依赖能量,该聚合酶被设计用于非自然核酸结合.
使用ITC阐明了SS_01的聚合和外核酶功能的机制性见解.
为了比较SS_01在Mg2+与Ca2+的存在下结合和催化效率.

主要方法:

使用异热定位热量计 (ITC) 来测量结合和催化能量.
这项研究使用了一种能够结合非自然核酸的Phi29突变聚合酶 (SS_01).
实验是在不同金属离子 (Mg2+和Ca2+) 和各种基质 (dNTP,与寡核酸标记的dNTP,未修改的寡核酸) 的存在下进行的.

主要成果:

SS_01与Mg2+呈现紧密结合 (KD = 243 nM),显示出明显的外热信号,表明具有催化能力的分子.
与Ca2+结合导致较弱的外热信号 (KD = 317 nM),这表明复合物的形成效率较低.
用Mg2+的聚合试验显示出明显的内热变化,而Ca2+则产生了最小的变化.
外核酶活性与Mg2+具有强烈的外热性,但与Ca2+具有弱的外热性,突出显示了严格的离子依赖.

结论:

ITC直接捕获SS_01DNA聚合酶的金属离子依赖的能量.
这些发现为SS_01.01的聚合和外核酶功能提供了机械洞察力.
金属离子选择 (Mg2+与Ca2+) 显著影响酶的结合亲和力,催化效率和整体热力学行为.

关键词:

Phi29 基因聚合酶基因聚合酶外核酶活动的外核酶活动.公司注册公司注册异热定位热量计异热定位热量计模板具有约束力的模板热力学分析的概况

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