稀溶液中线形DNA分子链结构及扩散的布朗动力学模拟

通过构建全参数化的珠一弹簧分子链模型,并运用一种高效稳定的半隐式预测-校验积分算法求解描述稀溶液中DNA分子链结构演化的随机动力学方程组,系统研究了体积排斥作用、有限伸长弹性作用和涨落流体动力学作用对分子链的回旋半径、质心扩散系数以及相应标度指数的影响.模拟结果能够验证良溶剂中分子链Zimm模型的标度规律,并揭示出3种...

Brownian dynamics simulation of conformation and diffusion of linear DNA chain in dilute solution

By constructing a full-parameterized bead-spring chain model and applying a highly efficient second-order semi-implicit predictor-corrector algorithm,the influence of three nonlinear interactions including excluded volume interaction,finite extensible nonlinear elastic interaction and fluctuating hydrodynamic interaction on the radius of gyration,diffusion coefficient and their scaling exponents are studied systematically.Simulation results validate the scaling law of Zimm model in good solvent and demonstrate different degrees and directions of these nonlinear effects.Chain flexibility has little influence on conformation and diffusion coefficient.The higher solvent quality clearly increases the radius of gyration and decreases the diffusion coefficient,and makes both quantities increase with the scaling exponents.In addition,the hydrodynamic interaction has little influence on the conformation of DNA chain,but it increases the diffusion coefficient and decreases its scaling exponent greatly.