Quarterly Reviews of Biophysics

Review Article

Single-molecule fluorescence to study molecular motors

Hyokeun Parka1, Erdal Topraka2 and Paul R. Selvina2a3 c1

a1 Department of Chemistry, University of Illinois, Urbana, IL, USA

a2 Center for Biophysics and Computational Biology, University of Illinois, Urbana, IL, USA

a3 Department of Physics, University of Illinois, Urbana, IL, USA

Abstract

Molecular motors, which use energy from ATP hydrolysis to take nanometer-scale steps with run-lengths on the order of micrometers, have important roles in areas such as transport and mitosis in living organisms. New techniques have recently been developed to measure these small movements at the single-molecule level. In particular, fluorescence imaging has contributed to the accurate measurement of this tiny movement. We introduce three single-molecule fluorescence imaging techniques which can find the position of a fluorophore with accuracy in the range of a few nanometers. These techniques are named after Hollywood animation characters: Fluorescence Imaging with One Nanometer Accuracy (FIONA), Single-molecule High-REsolution Colocalization (SHREC), and Defocused Orientation and Position Imaging (DOPI). We explain new understanding of molecular motors obtained from measurements using these techniques.

Correspondence:

c1 Author for correspondence: Dr P. R. Selvin, Physics Department, 1110 West Green Street, Loomis Laboratory, University of Illinois, Urbana, IL 61801, USA. Tel.: 217-244-3371; Fax: 217-244-7559; E-mail: selvin@uiuc.edu