通过代理方法来了解狭胺合成酶的双基质活性
Kulhar Nitin1, Eerappa Rajakumara1
1Macromolecular Structural Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Hyderabad (IITH), Kandi, Sangareddy 502284, Telangana, India.
International journal of biological macromolecules
|February 14, 2024
概括
斯特里克托西丁合成酶 (STRs) 催化了与各种基质的反应. 这项研究使用了代理方法来表征基质结合,揭示了STRs之间的不同合作性和告知酶工程.
科学领域:
- 酶学 是一种酶学.
- 生物催化剂是一种生物催化剂.
- 蛋白质 - 配体相互作用
背景情况:
- 斯特里克托西丁合成酶 (STRs) 催化皮克特-斯勒反应 (PSR),这是植物类生物合成的关键步骤.
- 虽然已知可以处理胺和secologanin,但STRs也可以接受具有不同催化效率的非同源基质.
研究的目的:
- 来自Rauvolfia serpentina (RsSTR) 和Ophiorrhiza pumila (OpSTR) 的STR正基因的双基质结合性 (顺序,亲和力,合作性) 的特征.
- 阐明基质识别和结合合作性的分子基础,使用非反应性三胺类同类物 (m1).
- 通过了解STR基质结合,为药物设计和酶工程工作提供信息.
主要方法:
- 基于异热定位热量计 (ITC) 的"代理方法",使用非反应性胺类类似物 (m1).
- 对RsSTR-(m1) 复合体进行晶体学研究.
- 密度函数理论 (DFT) 扫描以评估反应能量.
- 分子动力学模拟 (MDS) 用于研究pH对双基质结合的影响.
主要成果:
- OpSTR显示了"胺素第一"与胺素 (1) 的合作结合,以及与m1和secologanin (2) 的同时合作结合.
- 在OpSTR中,m1和secologanin之间的绑定合作性比RSSTR高.
- 结晶学揭示了RSSTR活跃部位内的m1的方向和相互作用.
- 据DFT的计算表明,使用m1的PSR在能源上是不可行的.
- MDS提供了关于复杂稳定性和pH依赖结合的分子基础的见解.
结论:
- STRs的双基质结合特征在各个orthologs之间存在差异,影响它们的催化性质.
- "代理方法"有效地描述了STR中的基质结合和合作性.
- 了解基质结合机制对于合理的酶工程和针对STR的药物设计至关重要.
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