缓慢的G-四重复变形重组和可访问性变化 诱导人体端粒单链DNA中的变化
Arianna N Lacen1, Andrew Symasek1, Alan Gunter1
1Department of Chemistry, University of Alabama at Birmingham, 901 14th Street South, Birmingham, Alabama 35294, United States.
The journal of physical chemistry. B
|June 14, 2024
概括
离子 (K+) 在端粒DNA中稳定G四复合体 (G4s),降低了它们的动态性和对补充链的可访问性. 这种形状变化影响了细胞环境中的端粒突起相互作用.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 富含关氨酸的端粒DNA序列可以折叠成G-四重复结构 (G4s).
- G4形成影响单链端粒突起的可访问性,这对于端粒维护至关重要.
- 众所周知, (Na+) 和 (K+) 等子会影响G4的稳定性和形状.
研究的目的:
- 调查Na+和K+对G-四折叠和可访问性的影响.
- 了解阳离子交换的动态及其对G4形状和稳定性的影响.
- 阐明这些发现对细胞环境中的端粒突起相互作用的含义.
主要方法:
- 差分扫描热量计 (DSC) 用于评估热稳定性.
- 循环二元化 (CD) 光谱法用于监测结构变化.
- 单分子Förster共振能量转移 (smFRET) 用于研究结构动力学和链结合可访问性.
主要成果:
- 与Na+溶液相比,K+溶液中形成的G4s具有较低的结构动力学和更高的热稳定性.
- 已经证明Na+和K+离子在G4结构中是可交换的.
- 暴露于高K+度会诱导G4s的缓慢形状重组,使它们抵抗互补链的展开.
结论:
- K+离子显著稳定了端粒G-四重复合体,改变了它们的结构动态和可访问性.
- 在高K+环境中观察到的缓慢重新排列表明G4可访问性的时间依赖的变化.
- 这些发现提供了关于G4可访问性是如何被子调节的关键见解,影响了与蛋白质和端粒酶的端粒突起相互作用.
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