Mechanical Manipulations of Single Molecules of DNA, Proteinand their Complexes

本应用程序描述了一系列实验，旨在研究DNA，蛋白质及其复合物在受到机械应力时的反应。这些研究是该实验室先前使用光学镊子和扫描力显微镜（SFM）等方法研究单分子力学响应的延续。提出的研究主要分为三大类：i)单个dsDNA分子的弹性响应研究；ii) RecA-DNA细丝的弹性响应研究；iii) T4溶菌酶和titin单分子机械变性的研究。这些研究的结果将对分子内力量的性质和大小提供全新的见解，这些力量将生物结构结合在一起。事实上，先前发表的关于单个dsDNA分子弹性的工作已经导致了DNA弹性的三种不同制度的表征。这三种机制可能在体内重组过程中发挥不同的作用。本文提出的实验将扩展这些研究，直接研究重组细丝的力学性能和单个蛋白质分子的变性。＊＊＊

9631153 Bustamante This application describes a series of experiments designed to investigate the response of DNA, proteins, and their complexes when subjected to mechanical stress. These studies are a continuation of previous effects by this laboratory to employ methods such as Optical Tweezers and Scanning Force Microscopy (SFM) to investigate the mechanical response of single molecules. The proposed studies are divided into three main groups: i) Studies of the elastic response of single dsDNA molecules; ii) Studies of the elastic response of RecA-DNA filaments; and iii) Studies of the mechanical denaturation of single molecules of T4 lysozyme and titin. %%% The results of these studies will provide completely new insights into the nature and magnitude of the intramolecular forces that hold together biological structures. In fact, previously published work on the elasticity of single dsDNA molecules has already resulted in the characterization of three distinctive regimes of DNA elasticity. These three regimes are likely to play different roles in the process of recombination in vivo. The experiments proposed here will extend these studies to directly investigate the mechanical properties of the recombinant filaments and the denaturation of single protein molecules. ***