亚蛋白质分子间相互作用和血红素插入用于3D域互换在线红蛋白.
Gissi Novientri1, Koji Takeda1, Lian Duan2,3
1Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
ACS omega
|March 3, 2025
概括
在线红蛋白 (Mb) 中的三维域交换 (3D-DS) 受血红插入的影响. 将Ala残留物引入Mb链区域显著增强了二元体的形成,这表明蛋白质折叠条件对于3D-DS至关重要.
科学领域:
- 蛋白质的生物化学 蛋白质的生物化学
- 结构生物学是结构生物学.
- 生物物理学的生物物理.
背景情况:
- 蛋白质,包括像肌球蛋白 (Mb) 这样的血红蛋白,可以经历三维域交换 (3D-DS).
- 在Mb中,3D-DS涉及E-F螺旋环转换为螺旋结构,形成二度.
- 3D-DS和heme插入在Mb之间的准确关系尚未完全理解.
研究的目的:
- 系统地调查野生类型 (WT) Mb及其变体接受3D-DS.的倾向.
- 探索引入氨酸 (Ala) 残留物进入链区域对Mb二分化的影响.
- 阐明apomonomer-dimer平衡和蛋白质折叠条件在Mb 3D-DS中的作用.
主要方法:
- 在70°C进行30分钟的热变性试验,以诱导WT Mb和Ala变体中的3D-DS (G80A,G80A/H81A,G80A/H81A/H82A).
- 来自大肠杆菌的Mb变体的表达和净化,以评估体内二元体的形成.
- 复制apo Mb变体以评估独立于血质的二分体形成.
- 分子动力学 (MD) 模拟来分析链区域的结构变化和稳定.
主要成果:
- 加热WT Mb单体没有产生可检测的二元体,而Ala变体显示出显著的二元体形成 (55-92%).
- 在体内表达和apo Mb复制显示了WT < K3AH2 < K3A2H < K3A3.3.3的序列中增加的二元比率.
- K3A2H Mb 模分器通过链上的键网络显示稳定.
- MD研究支持在链区域稳定α螺旋增强K3A3 Mb中的二元体形成.
结论:
- 活体中Mb 3D-DS二元体的形成取决于在血插入之前的apo单元体-二元体平衡.
- 在 Mb 链区域的 Ala 替代物显著促进了 3D-DS 和二元体的形成.
- 蛋白质折叠条件,特别是链区域螺旋的稳定,在影响Mb 3D-DS倾向方面发挥着关键作用.
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