arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.07387physics.bio-phq-bio.SC
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结合受体-配体复合物数目的平衡概率分布

Equilibrium Probability Distribution for Number of Bound Receptor-Ligand Complexes

Tuhin Chakrabortty, Manoj M Varma

摘要:

分子结合的现象,其中两个分子,称为受体和配体,结合在一起形成配体-受体复合物,在生物学中普遍存在,并且对于所有生命维持过程的准确功能至关重要。在热平衡下,单个受体与周围的L配体分子中的任何一个形成复合物的概率可以从由吉布斯-玻尔兹曼分布获得的配分函数导出。我们将这种方法扩展到由R受体和L配体组成的系统,推导出概率密度函数p(r;R,L),以找到r结合的受体-配体复合物在热平衡。这种扩展使我们能够说明这个问题的两个方面,这在单一受体问题中是不明显的,即a)在R和L交换下结合复合物数量的平衡分布中预期的对称性和b)从化学动力学方程获得的结合复合物的数量与p(r;R,L)表达式中r的最大可能值精确对应。我们推导出r的数量波动,并提出了一个实际相关的分子传感应用程序,受益于p(r;R,L)的知识。

英文摘要:

The phenomenon of molecular binding, where two molecules, referred to as a receptor and a ligand, bind together to form a ligand-receptor complex, is ubiquitous in biology and essential for the accurate functioning of all life-sustaining processes. The probability of a single receptor forming a complex with any one of L surrounding ligand molecules at thermal equilibrium can be derived from a partition function obtained from the Gibbs-Boltzmann distribution. We extend this approach to a system consisting of R receptors and L ligands to derive the probability density function p(r;R,L) to find r bound receptor-ligand complexes at thermal equilibrium. This extension allows us to illustrate two aspects of this problem which are not apparent in the single receptor problem, namely, a) a symmetry to be expected in the equilibrium distribution of the number of bound complexes under exchange of R and L and b) the number of bound complexes obtained from chemical kinetic equations has an exact correspondence to the maximum probable value of r from the expression for p(r;R,L). We derive the number fluctuations of r and present a practically relevant molecular sensing application that benefits from the knowledge of p(r;R,L).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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