T. Yanagida
Yanagida Biomotron Project, JRDC, Mino, Osaka, Japan.
We have refined total internal reflection fluorescence microscopy (TIRFM) to visualize single fluorescent dye molecules in aqueous solution at a full video rate. This new fluorescence microscopy allowed us to directly image individual ATPase reactions and motions by a single motor protein (Nature, 374, 555- '95; Nature, 380, 451-'96). Furthermore, we have extended this method to single molecule spectroscopy and FRET. Using the single molecule spectroscopy and FRET, we could directly monitor subunit dynamics in a single Ca-binding protein and protein-protein communication at a single molecule level (BS(US), Abs.'97). Combining this method for single molecule imaging with manipulation of a single molecule by laser trapping nanometry, we have succeeded in simultaneous measurements of single molecule mechanics and the ATPase reaction by a motor protein (BS(US), Abs.'97). We are applying these new methods to studies on mechnaochemical energy transduction in molecular motors, DNA -protein interaction and signal transduction in cell.