University of Maryland Baltimore County, Baltimore, MD 21250, USA.
Colloids Surf B Biointerfaces. 2013 Jan 1;101:501-9. doi: 10.1016/j.colsurfb.2012.07.020. Epub 2012 Jul 27.
Single molecule force spectroscopy is widely used to determine kinetic parameters of dissociation by analyzing bond rupture data obtained via applying mechanical force to cells, capsules, and beads that are attached to an intermolecular bond. The current analysis assumes that the intermolecular bond force is equal to the externally applied mechanical force. We confirm that viscous drag alone or in combination with cellular deformation resulting in viscoelasticity modulates bond force so that the instantaneous intermolecular bond force is not equivalent to the applied force. The bond force modulation leads to bond rupture time and force histograms that differ from those predicted by probability distribution function (PDF) using the current approach. A new methodology that accounts for bond force modulation in obtaining PDF is presented. The predicted histograms from the new methodology are in excellent agreement with the respective histograms obtained from Monte Carlo simulation.
单分子力谱广泛用于通过分析通过向附着在分子间键上的细胞、胶囊和珠施加机械力而获得的键断裂数据来确定离解的动力学参数。当前的分析假设分子间键力等于外部施加的机械力。我们证实，仅粘性阻力或与导致粘弹性的细胞变形相结合会调节键力，从而使瞬时分子间键力与施加的力不相等。键力调制导致键断裂时间和力直方图与当前方法使用概率分布函数 (PDF) 预测的直方图不同。提出了一种在获取 PDF 时考虑键力调制的新方法。从新方法预测的直方图与从蒙特卡罗模拟获得的相应直方图非常吻合。
