通过酸化调节心脏热素的结构和动力学,并通过分子动力学模拟揭示的突变
Zeyu Yang1,2, Steven B Marston3, Ian R Gould1,2
1Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, Shepherd's Bush, London W12 0BZ, U.K.
The journal of physical chemistry. B
|October 4, 2023
概括
上腺素可以通过PKA对心脏素I的酸化来增强心脏的放松 (lusitropy). 这项研究揭示了酸化如何影响热素动态,并揭示了心肌病突变中的刚性结构.
科学领域:
- 心血管生理学心血管生理学
- 分子心脏病学分子心脏病学
- 生物物理学的生物物理.
背景情况:
- 上腺素通过PKA激活来增强心脏收缩性和缩性.
- 心脏素I (cTnI) 在22和23序列的酸化对性来说至关重要.
- 心肌病突变可以破坏这种依赖酸化的调制.
研究的目的:
- 为了研究素对PKA酸化的反应中素的结构动态.
- 为了比较野生类型的素与家族扩展性心肌病变异体 (cTnC G159D) 的动态.
- 了解酸化如何影响热素结构及其与Ca2+的相互作用.
主要方法:
- 全原子分子动力学模拟特罗邦尼核心 (419 个氨基酸).
- 在Ca2+的存在下,对5×1.5μs的运行进行了模拟.
- 分析了野生类型和突变型热素的双酸化和非酸化状态.
主要成果:
- 化PKA诱导野生类型的热素显著硬化.
- 关键的结构变化包括改变的cTnI(1-33) -cTnC相互作用和cTnI开关的修改对接.
- cTnC G159D突变体表现出固有的刚性,其酸化效应与野生类型相反.
结论:
- 通过PKA的酸化会动态调节热素结构,影响心脏功能.
- G159D突变赋予了刚性,并改变了对酸化的反应,导致心肌病.
- 了解这些分子动力学是解读心脏病机制的关键.
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