在表面附着生物分子的折叠自由能量上的热和静电效应:一个实验和理论研究
Herschel M Watkins1, Alexis Vallée-Bélisle, Francesco Ricci
1Interdepartmental Program in Biomolecular Science and Engineering, University of California, Santa Barbara, California 93106, USA.
Journal of the American Chemical Society
|January 14, 2012
概括
生物分子的表面粘附会影响它们的折叠. 这项研究表明,由于在充电表面上竞争的排斥体积和静电效应,DNA茎环折叠能量的变化具有离子强度.
科学领域:
- 生物物理学的生物物理.
- 表面化学 表面化学
- 分子生物学分子生物学
背景情况:
- 表面绑定的生物分子在生物过程和生物技术中至关重要.
- 关于表面粘附的物理后果的理论研究存在,但实验研究有限.
- 了解表面相互作用如何影响生物分子行为,对于推进生物技术至关重要.
研究的目的:
- 通过实验和理论研究表面附着对生物分子折叠自由能量的影响.
- 量化DNA干循环在被附着在充电表面时折叠自由能量的变化.
- 阐明影响表面生物分子稳定性的竞争机制.
主要方法:
- 测量了溶液中的DNA干环的折叠自由能量.
- 量化了DNA茎环部位的折叠自由能量 - - 特别附着在负电荷的,基甲涂层的金表面上.
- 采用了表面结合的多电解质的静电学和表面结合的聚合物的理论模型.
主要成果:
- 表面附着在低离子强度下破坏了DNA干循环的稳定.
- 表面附着稳定了DNA干循环在约130mM以上的离子强度.
- 理论模型在数量上与没有拟合参数的实验结果相匹配.
结论:
- 观察到的行为归因于竞争的排除体积效应 (稳定) 和电荷表面的静电排斥 (在低离子强度下不稳定).
- 目前的表面静电学和聚合物的理论准确地描述了这种系统中与表面结合的生物分子的行为.
- 这项研究提供了对表面生物分子相互作用的定量理解,这对于设计先进生物技术至关重要.
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