Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, Japan; E-Mails:
Int J Mol Sci. 2012;13(1):453-65. doi: 10.3390/ijms13010453. Epub 2011 Dec 29.
Dynamic force spectroscopy (DFS) makes it possible to investigate specific interactions between two molecules such as ligand-receptor pairs at the single-molecule level. In the DFS method based on the Bell-Evans model, the unbinding force applied to a molecular bond is increased at a constant rate, and the force required to rupture the molecular bond is measured. By analyzing the relationship between the modal rupture force and the logarithm of the loading rate, microscopic potential barrier landscapes and the lifetimes of bonds can be obtained. However, the results obtained, for example, in the case of streptavidin/biotin complexes, have differed among previous studies and some results have been inconsistent with theoretical predictions. In this study, using an atomic force microscopy technique that enables the precise analysis of molecular interactions on the basis of DFS, we investigated the effect of the sampling rate on DFS analysis. The shape of rupture force histograms, for example, was significantly deformed at a sampling rate of 1 kHz in comparison with that of histograms obtained at 100 kHz, indicating the fundamental importance of ensuring suitable experimental conditions for further advances in the DFS method.
动态力谱（DFS）使得在单分子水平上研究特定分子间的相互作用（如配体-受体对）成为可能。在基于贝尔-埃文斯模型的 DFS 方法中，以恒定的速率增加施加在分子键上的解键力，并测量断开分子键所需的力。通过分析模态断裂力与加载速率对数之间的关系，可以获得微观势垒景观和键的寿命。然而，例如在链霉亲和素/生物素复合物的情况下，以前的研究结果存在差异，并且一些结果与理论预测不一致。在这项研究中，我们使用原子力显微镜技术，基于 DFS 精确分析分子相互作用，研究了采样率对 DFS 分析的影响。例如，与在 100 kHz 时获得的直方图相比，在采样率为 1 kHz 时，断裂力直方图的形状明显变形，这表明确保适当的实验条件对于 DFS 方法的进一步发展至关重要。
