Adeleke-Larodo Tunrayo, Illien Pierre, Golestanian Ramin
Rudolf Peierls Centre for Theoretical Physics, University of Oxford, OX1 3NP, Oxford, UK.
Department of Chemistry, The Pennsylvania State University, 16802, University Park, PA, USA.
Eur Phys J E Soft Matter. 2019 Mar 28;42(3):39. doi: 10.1140/epje/i2019-11799-5.
We recently introduced a model of an asymmetric dumbbell made of two hydrodynamically coupled subunits as a minimal model for a macromolecular complex, in order to explain the observation of enhanced diffusion of catalytically active enzymes. It was shown that internal fluctuations lead to a negative contribution to the overall diffusion coefficient and that the fluctuation-induced contribution is controlled by the strength of the interactions between the subunits and their asymmetry. We develop the model by studying the effect of anisotropy on the diffusion properties of a modular structure. Using a moment expansion method we derive an analytic form for the long-time diffusion coefficient of an asymmetric, anisotropic dumbbell and show systematically its dependence on internal and external symmetry. The method provides a tractable, analytical route for studying the stochastic dynamics of dumbbell models. The present work opens the way to more detailed descriptions of the effect of hydrodynamic interactions on the diffusion and transport properties of biomolecules with complex structures.
我们最近引入了一种由两个流体动力学耦合亚基组成的不对称哑铃模型，作为大分子复合物的最小模型，以解释催化活性酶扩散增强的现象。研究表明，内部涨落对整体扩散系数有负贡献，且涨落诱导的贡献受亚基间相互作用强度及其不对称性的控制。我们通过研究各向异性对模块化结构扩散特性的影响来拓展该模型。使用矩展开法，我们推导了不对称、各向异性哑铃长时间扩散系数的解析形式，并系统地展示了其对内部和外部对称性的依赖性。该方法为研究哑铃模型的随机动力学提供了一条易于处理的解析途径。目前的工作为更详细地描述流体动力学相互作用对具有复杂结构生物分子的扩散和传输特性的影响开辟了道路。
