Tshiprut Zion, Urbakh Michael
School of Chemistry, Tel Aviv University, 69978 Tel Aviv, Israel.
J Chem Phys. 2009 Feb 28;130(8):084703. doi: 10.1063/1.3077867.
We propose an analytical approach to describe the active rebinding and force hysteresis observed in single-molecule pulling experiments. We derive equations for dependences of the measured quantities on the properties of molecular potential, effective stiffness of the pulling spring, and the pulling velocity. The calculations predict that the energy dissipated per an unbinding-rebinding cycle strongly increases with the steepness of the molecular potential and with decreasing the spring stiffness. A comparison of analytical results with Langevin simulations shows that the scaling relations for the barrier heights and most probable forces are more accurate in the case of active rebinding than for unbinding. Our consideration demonstrates that simultaneous analysis of probability density functions for unbinding and rebinding forces improves essentially the accuracy of retrieval information on intrinsic parameters of the molecular complex from the force measurements.
我们提出一种分析方法来描述在单分子拉伸实验中观察到的活性重结合和力滞后现象。我们推导了测量量与分子势特性、拉伸弹簧的有效刚度以及拉伸速度之间的依赖关系方程。计算结果预测，每个解离 - 重结合循环耗散的能量会随着分子势的陡峭程度增加以及弹簧刚度的降低而显著增加。分析结果与朗之万模拟的比较表明，对于活性重结合情况，势垒高度和最概然力的标度关系比解离情况更准确。我们的研究表明，同时分析解离力和重结合力的概率密度函数能从力测量中显著提高获取分子复合物内在参数信息的准确性。
