Single Molecule Studies in Chemical Biology and Nanosciences

Abstract

Modern ultra-sensitive instrumental skill and expertise on surface modification of single biological molecules have sharpened the capabilities of scientists to address important current problems and explore new frontiers in many sci- entific disciplines including chemistry, molecular biology, molecular medicine and nano-structured materials. Develop- ment in single molecule studies (SMS) and manipulation (SMM) in the past two decades has unearthed very important in- formation hidden in chemical biology and nanosciences that was not possible earlier by ensemble measurements. For ex- ample, studying motion of biological motors like ATP synthase, DNA polymerase, RNA polymerase, etc could only be possible through single molecule manipulation. Single molecule fluorescence spectroscopy and studies could, for the first time directly show the surface dependent catalytic activities of a catalyst and angular distribution of emission of single chromophore unit. Estimation of step size of linear motors like myosin, kinesin, dynein, etc. was possible due to the de- velopment of single molecule fluorescence imaging with one nanometer accuracy and other techniques. Single molecule fluorescence resonance energy transfer could measure the distance between two moieties present in a single biomolecule and study the kinetics. Twisting DNA topoisomerase was directly observed by single molecule imaging technique. The dynamic properties of biomolecules through SMS have been expanding to DNA sequencing, sizing, conformational study, protein-DNA interaction, molecular motors, protein folding, conformational study, diffusion of single biomolecule in membrane, biomolecular reaction dynamics and single virus tracing etc. In this review our focus is to summarize some of the recent developments in single molecule studies and manipulation as mentioned above in chemical biology and nanosciences.