单分子光镊技术在生命科学中的应用

Applications in Life Science of Single-molecule Optical Tweezers

单分子光镊技术是近年来发展起来的一种新型的高分辨率光学技术,可以在单分子水平上实时观测并研究生物大分子或复合物相互作用的动态行为。光镊次毫秒级的时间分辨率和皮牛顿的力分辨率可使我们精确获得中间态、折叠速率(两态迁移速率)、作用力、能量、距离等重要的动力学信息;不同于传统的结构生物学方法,光镊实验是在生理条件下进行的,这些优势都使得光镊技术成为生物物理学领域一项不可或缺的技术手段。该文将主要针对这项单分子光学技术的原理及其在生物动力学上的应用和发展前景作简要介绍。

Optical tweezers are an emerging optical technology with high-resolution for investigating real- time dynamics of macromolecules and complexes at single-molecule levels. With a sub millisecond time response, it is utilized to determine the intermediate states and folding rates. Optical tweezers are very sensitive for a force change in response of end-to-end length change of a molecule. Therefore it can accurately provide the informa- tion for mechanical forces, conformational changes and energy, which are the key information for kinetic studies.Furthermore, unlike the conventional structural biology methods, optical tweezers experiments are pcrtbrmed in a physiological condition. With all these advantages, optical tweezers became an irreplaceable biophysical method for studying dynalnic biological processes. 111 this review, we mainly tbcus on the basic principles of optical twee- zers and their applications especially in protein folding, chromatin remodeling and other molecular motors. We also briefly discuss the future developments of this technology.