凝血胺酶折叠成一个G-四复合体与Sr(2+):稳定性,热量和水合
1Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE 68198-6025, USA.
Journal of the American Chemical Society
|November 1, 2001
概括
DNA 体形成 G-四重复结构与金属离子. 最佳的离子大小,比如Sr2+),增强了复杂的稳定性,并影响了水化效应,这对于理解体功能至关重要.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子生物物理学 分子生物物理学
背景情况:
- DNA 体可以形成G-四重复结构,特别是d(G(2)T(2)G(2)TGTG(2)T(2)G(2)) 与K+.
- 这些G-quadruplex结构与对象如血栓激素的aptamer亲和力有关,影响生物过程.
研究的目的:
- 研究各种单价和双价金属离子的G-四重复形成的光谱特征,热力学和水合.
- 为了将金属离子特性,特别是离子半径,与G-四重复合体稳定性和结合热力学相关联.
主要方法:
- 使用了光谱,热量计,密度和超声技术的组合.
- 分析了循环二元化 (CD) 光谱和化概况,以评估复杂的形成和稳定性.
- 确定了热力学参数 (过渡温度,结合热量) 和水化效应.
主要成果:
- 具有1.3-1.5 Å的离子半径的单价离子 (K+,Rb+,NH4+) 和双价离子 (Sr2+,Ba2+) 形成稳定的分子内G四重复体,过渡温度>25°C.
- 不同半径的离子 (Li+,Na+,Cs+,Mg2+,Ca2+) 在较低的温度下形成较弱的复合体.
- 斯里2+) - 胺复合物比K+-胺复合物更稳定 (ΔT ≈ 18°C高),具有明显的热力学结合度.
结论:
- 金属离子的大小是稳定的G-四重复形成的关键决定因素.
- 含有阴离体脱水和折叠过程中吸收水分的水化效应,对结合热力学有显著的贡献.
- 结果提供了对胺体 - 金属离子相互作用的见解,与胺体设计和治疗应用有关.
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