Dresden 2017 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

BP: Fachverband Biologische Physik

BP 10: Posters - Single Molecule Biophysics

BP 10.4: Poster

Montag, 20. März 2017, 17:30–19:30, P3

Mechanical Properties of Leishmania Myosin XXI determined with an Optical Tweezers based Force Transducer — •Andreas Graw, Christopher Batters, and Claudia Veigel — Department of Cellular Physiology (LMU) and Center for Nanoscience (CeNS), München, Germany

Myosins form a large family of actin-based motor proteins that are involved in different forms of cellular motility. Force and movement are generated by changes in conformation of the actomyosin complex. Myosin XXI is the only myosin shown to be expressed in Leishmania parasites and is involved in a variety of motile functions. Previous studies indicated that members of the calmodulin family regulate dimerization, motility, and lipid binding of this molecular motor.

Here we present the first mechanical measurements to determine the stiffness and working stroke of a single myosin XXI motor molecule using optical tweezers. These measurements are performed using the "three bead" geometry in which an actin filament is stretched out via two optically trapped handle beads attached to either end of the filament to form a dumbbell. The dumbbell is positioned in the vicinity of a third bead carrying the myosin motor². The movements and forces produced by the actomyosin interactions are observed by detecting the position of both trapped beads with four-quadrant-photodiodes. In order to characterize the effect of the C-terminal tail on the mechanical performance of the motor we immobilized the motor using different attachment modes including physiological phospholipids.