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活性部位疏水性相互作用在促进人类终端脱氧核乙烯转移酶催化中的作用

Svetlana I Senchurova¹, Timofey E Tyugashev¹, Nikita A Kuznetsov^1,2

¹Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia.

International journal of molecular sciences

|January 10, 2026

概括

在Loop1中的疏水性相互作用对终端脱氧核样转移酶 (TdT) 的催化功能至关重要. 破坏这些相互作用会损害TdT结合核酸的能力,影响免疫受体的多样性.

科学领域:

生物化学生物化学
分子生物学分子生物学
免疫学免疫学免疫学

背景情况:

终端脱核样转移酶 (TdT) 通过模板独立的DNA合成对免疫受体多样性至关重要.
已知Loop1在TdT的结构和功能中的作用,但其疏水性相互作用的影响尚不清楚.

研究的目的:

为了研究特定的疏水性残留物 (L397,F400,F404) 在人类TdT的Loop1中的作用.
了解这些疏水性相互作用如何影响TdT的结构,稳定性和催化机制.

主要方法:

用局部导向的突变生成来创建L397,F400和F404的氨酸和氨酸替代物.
用分子动力学模拟和稳定状态前动力学测试来分析突变的TdT形式.

主要成果:

突变L397A和F400A增加了Loop1的灵活性,降低了催化活性,特别是对于 purin的结合.
F404A突变取消了TdT的酶活性,而F404W在很大程度上保留了它.
突变者保持了DNA和dNTP的结合,但在某些情况下显示出减少的亲和力和热稳定性.

结论:

在Loop1内的疏水相互作用对于维持TdT的催化活性构造至关重要.
这些相互作用对于精确的基质定位和DNA合成期间的活性位点稳定性至关重要.
了解这些机制可以了解TdT的功能和潜在的治疗点.

关键词:

分子动力学分子动力学核酸结合的结合蛋白DNA相互作用模板独立的DNA合成终端脱氧核乙烯转移酶.

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