Nano-manipulation of actomyosin molecular motors in vitro: a new working principle.

Techniques have been recently developed that allow the direct observation of single actin filaments and their manipulation, using glass microneedles, in the nanometer range. Further development of these techniques has made possible the detection of subpiconewton-level forces of individual myosin heads. This in vitro motility model is sensitive in the submillisecond range and has allowed us to determine the force generation of an actomyosin motor directly at the molecular level. The results have led to a new conceptual framework for chemo-mechanical energy transduction in the molecular motor.