Luan Binquan, Aksimentiev Aleksei
Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Aug;78(2 Pt 1):021912. doi: 10.1103/PhysRevE.78.021912. Epub 2008 Aug 26.
Extensive all-atom molecular dynamics simulations were performed to characterize the microscopic origin of the force experienced by DNA in a bulk electrolyte and a solid-state nanopore when subject to an external electrostatic field E. The effective screening of the DNA charge was found to originate from the hydrodynamic drag of the electro-osmotic flow that is driven by the motion of counterions along the surface of DNA. We show that the effective driving force F in a nanopore obeys the same law as in a bulk electrolyte: F=ximuE , where xi and mu are the friction coefficient and electrophoretic mobility of DNA, respectively. Using this relationship, we suggest a method for determining the effective driving force on DNA in a nanopore that does not require a direct force measurement.
进行了广泛的全原子分子动力学模拟，以表征在外部静电场E作用下，DNA在本体电解质和固态纳米孔中所受力的微观起源。发现DNA电荷的有效屏蔽源于由反离子沿DNA表面运动驱动的电渗流的流体动力学阻力。我们表明，纳米孔中的有效驱动力F与本体电解质中的遵循相同规律：F = ξμE，其中ξ和μ分别是DNA的摩擦系数和电泳迁移率。利用这种关系，我们提出了一种无需直接测量力即可确定纳米孔中DNA有效驱动力的方法。
