Theoretical insights into mechanisms of channel-facilitated molecular transport in the presence of stochastic gating
Theoretical insights into mechanisms of channel-facilitated molecular transport in the presence of stochastic gating
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DOI：
10.1063/1.5086224
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发表时间：
2019-03-28
影响因子：
4.4
通讯作者：
Kolomeisky, Anatoly B.
中科院分区：
文献类型：
--
作者：
Davtyan, Aram;Kolomeisky, Anatoly B.
分子通过孔隙的运动在各种自然和工业过程中起着至关重要的作用。生物通道促进转运的最吸引人的特征之一是随机门控过程，即通道在转运过程中在几种构象之间动态波动。尽管人们对这种现象进行了深入的研究，但在微观上，动态变化环境中易位的许多性质仍然没有得到很好的理解。我们开发了一个离散状态的随机框架，通过显式计算通过孔隙的分子通量来分析具有随机门控的传输过程的分子机制。具体研究了两种情况：（1）保持对称性的随机门控与自由能的变化和（2）随机门控与对称性的变化，但没有修改的整体粒子-孔隙相互作用。研究发现，随机门控可以加速或减慢分子的移位，这取决于系统的具体参数。我们认为，生物系统可能会优化其性能，利用通道的构象波动。我们的理论分析阐明了随机门控传输分子机制的物理化学方面。由AIP Publishing授权出版。
Molecular motion through pores plays a crucial role in various natural and industrial processes. One of the most fascinating features of biological channel-facilitated transport is a stochastic gating process, when the channels dynamically fluctuate between several conformations during the translocation. Although this phenomenon has been intensively investigated, many properties of translocation in a dynamically changing environment remain not well understood microscopically. We developed a discrete-state stochastic framework to analyze the molecular mechanisms of transport processes with stochastic gating by explicitly calculating molecular fluxes through the pores. Two scenarios are specifically investigated: (1) symmetry preserving stochastic gating with free-energy changes and (2) stochastic gating with symmetry changes but without modifications in the overall particle-pore interactions. It is found that stochastic gating can either accelerate or slow down the molecular translocation depending on the specific parameters of the system. We argue that biological systems might optimize their performance by utilizing conformational fluctuations of channels. Our theoretical analysis clarifies physical-chemical aspects of the molecular mechanisms of transport with stochastic gating. Published under license by AIP Publishing.