Thermodynamics of force-dependent folding and unfolding of small protein and nucleic acid structures.
Thermodynamics of force-dependent folding and unfolding of small protein and nucleic acid structures.
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DOI：
10.1039/c5ib00038f
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发表时间：
2015-10
期刊：
影响因子：
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通讯作者：
Mingxi Yao;Hu Chen;Jie Yan
中科院分区：
文献类型：
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作者：
Mingxi Yao;Hu Chen;Jie Yan
在本文中，我们概述了理解蛋白质结构域和小核酸结构的平衡力依赖的折叠和展开转变的理论框架，它们都具有小的刚性折叠结构和高度柔性的未展开聚合物链构象。得到了由概率函数ρ(ξ)（n,x）描述的状态的完整统计描述，其中n是表示结构状态的指标，x是分子的延伸。ξ表示施加在分子上的外部约束，它要么是一个恒定的力，要么是附着在分子一端的谐波弹簧。以经典titin I27结构域的力相关结构跃迁为例，分析了与结构状态无关的可拓概率分布：，自由能图：-kBT ln(ρ(ξ)(x))，以及与可拓无关的状态概率：。讨论了不同外部约束的影响。
In this paper, we outline the theoretical framework for understanding the equilibrium force-dependent folding and unfolding transitions of protein domains and small nucleic acid structures, both having small rigid folded structures and highly flexible unfolded polymeric chain conformations. A complete statistical description of the state described by the probability function ρ(ξ)(n,x), is obtained, where n is an index denoting the structural state, and x is the extension of the molecule. ξ denotes an external constraint applied to the molecule, which is either a constant force or a harmonic spring attached to one end of the molecule. The extension probability distribution regardless of the structural state: , the free energy landscape: -kBT ln(ρ(ξ)(x)), and the probability of the states regardless of the extension: , are analyzed using the force-dependent structural transitions of the classic titin I27 domain as an example. The impact of different external constraints is also discussed.