激光双光镊在单分子生物物理中的研究进展  

Advances in Laser Dual⁃Trap Optical Tweezers in Single⁃Molecule Biophysics

作　　者：巩凡 任煜轩 Gong Fan;Ren Yuxuan(National Facility for Protein Science in Shanghai,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201210,China;Institute for Translational Brain Research,Shanghai Medical College,Fudan University,Shanghai 200032,China)

机构地区：[1]中国科学院上海高等研究院国家蛋白质科学研究(上海)设施,上海201210 [2]复旦大学上海医学院脑科学转化研究院,上海200032

出　　处：《中国激光》2023年第15期229-253,共25页Chinese Journal of Lasers

摘　　要：光镊采用聚焦的激光束束缚微米、纳米级的粒子,具有亚皮牛级的力分辨率和亚毫秒级的时间响应,在单分子生物物理中具有广泛的应用.通过化学耦链将生物大分子连接到高分子微球上,光镊可以测量大分子的伸长以及受力,进而研究DNA-蛋白质相互作用、蛋白质折叠及分子马达机械化学性质等动态过程.简要介绍光镊的基本原理和常见的单分子光镊几何构型,并以双光镊为例,介绍如何设计和搭建光镊设备、所涉及的技术原理、稳定性与降噪处理方法以及分辨率测试方法.以国家蛋白质科学研究(上海)设施的双光镊实验装置为例,论述双光镊在单分子生物物理中的应用及进展.最后,对单分子光镊技术的发展前景作出展望.Significance Optical tweezers are a highresolution force measuring technique invented by A.Ashkin and colleagues in 1986.Optical tweezers,in brief,use a highly focused laser beam that can form a stable threedimensional trap to manipulate micronsized particles.Optical tweezers have subpiconewton force resolution and submillisecond time response,which can be widely used in singlemolecule biophysics.In singlemolecule optical tweezers experiment,traditional optical tweezers geometries include singletrap and dualtrap geometries.Compared with the singletrap geometries,the dualtrap“dumbbell”assay has better stability and noise resistance,resulting in higher resolution and playing an important role in the study of DNAprotein interactions,protein folding and the mechanochemical properties of molecular motors.In this review,we provide an overview on the basic principles of optical tweezers and the experimental setup of the dualbeam optical tweezers in the National Facility for Protein Science in Shanghai.The application and progress of dualbeam optical tweezers in singlemolecule biology are summarized,and we focus on investigating some perspectives for future applications.Progress When a photon is absorbed by an absorptive particle,the partial momentum of the photons is transferred to the particle,which in turn generates an optical trapping force that stabilizes the particle.Quantitative calculation of the optical trapping force depends on the wavelength of the trapping light and the size of the trapped particle.When the particle radius is close to or greater than the light wavelength,the optical trapping forces can be calculated from“rayoptics”model.When the particle size is smaller than the wavelength,the electromagnetic scattering theory is often chosen as the calculation model(Fig.1).Optical tweezers are mainly used in the study of single biomolecules such as proteins and nucleic acids.The systems commonly used in singlemolecule optical tweezers experiments include singletrap optical tweezers,dualtrap optical t

关 键 词：生物光学 双光镊 单分子 蛋白质折叠 分子马达 光学力 

分 类 号：O436[机械工程—光学工程]