Single molecule mechanics of molecular motors.
Robert Simmons (King’s College - Londres)

Jeudi 3 mai 2001

Research on the mechanical properties of single biomolecules has become a major field in the last 10 years. My group works on two such problems, both using the optical tweezers (laser trap) technique to manipulate proteins attached to trapped polystyrene beads.

- 1. Myosin is a "motor protein" which is responsible for muscle contraction. It interacts with another protein, actin, which is a filamentous polymeric protein consisting of two chains of monomers twisted together. In recent experiments with improved stability, we can see details of the binding sites for myosin along the actin filament with 1 nm resolution.

- 2. Titin is another polymeric muscle protein, responsible for the passive elasticity in muscle. We measured the polymer properties of titin and showed that the monomers unfold reversibly under force. We speculate on the physiological importance of this mechanism.