Single Molecules Manipulations in Biophysics

Until very recently, chemists and biochemists have had to rely on bulk methods to investigate the properties of molecules and their reactions. These methods did not make it possible to directly investigate the nature, strength, and direction of intermolecular forces and torques.

During the last few years, however, the advent of novel methods of single-molecule manipulation have begun to offer researchers, for the first time, the opportunity to measure directly the forces holding molecular structures together, to measure the stresses and strains generated in the course of chemical and biochemical reactions, to exert external forces to alter the fate of these reactions, and to reveal the rules that govern the interconversion of mechanical and chemical energy in these reactions. This area of research can be rightly called mechanochemistry.

Biochemical processes as diverse as protein folding, DNA elasticity, the protein-induced bending of DNA, the stress-induced catalysis of enzymes, the mechanical properties of protein motors, and even the ubiquitous process of induced-fit molecular recognition of proteins for their ligands, are all examples in which stresses and strains develop in molecules as they move along a reaction coordinate.

to be continued

reference: Bustamante, C.Of torques, forces, and protein machines(2004) Protein Science, 13 (11), pp. 3061-3065.doi: 10.1110/ps.041064504