Department of NanoEngineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0448, USA.
Phys Chem Chem Phys. 2011 Feb 7;13(5):1836-42. doi: 10.1039/c0cp01528h. Epub 2010 Oct 11.
In single-molecule force spectroscopy, individual molecules and complexes are often stretched by pulling devices via intervening molecular handles. Accurate interpretation of measurements from such experiments in terms of the underlying energy landscape, defined by activation barriers and intrinsic rates of transition, relies on our understanding, and proper theoretical treatment, of the effects of the pulling device and handle. Here, we present a framework based on Kramers' theory that elucidates the dependence of measured rupture forces and rates on the pulling device stiffness and attributes of the handle, contour length and persistence length. We also introduce a simple analytic model that improves prediction of activation barriers and intrinsic rates for all device stiffnesses and handle properties, thus allowing for a more reliable interpretation of experiments. Our analyses also suggests intuitive ways of displaying the measured force spectra for proper prognosis of device and handle effects and provides the range of device and handle attributes over which these effects can be neglected.
在单分子力谱学中，通常通过介入的分子手柄通过拉伸设备来拉伸单个分子和复合物。要根据激活势垒和固有跃迁速率定义的基础能量景观来准确解释此类实验中的测量结果，就需要我们理解并对拉伸设备和手柄的影响进行适当的理论处理。在这里，我们提出了一个基于克拉默斯理论的框架，阐明了测量的断裂力和速率与拉伸设备刚度以及手柄的特性、轮廓长度和持久长度之间的关系。我们还引入了一个简单的分析模型，该模型可以提高所有设备刚度和手柄特性的激活势垒和固有速率的预测，从而可以更可靠地解释实验。我们的分析还提出了直观的方法来显示测量的力谱，以便对设备和手柄的影响进行正确的预后，并提供了可以忽略这些影响的设备和手柄属性范围。
