Electrophoretic control of actomyosin motility

摘要

The effect of DC electric field strength on in vitro actomyosin motility was examined. Rabbit skeletal muscle heavymeromyosin (HMM) was adsorbed to nitrocellulose-coated glass, and the myosin driven movement of fluorescentlylabeled actin filaments was recorded in the presence of 0 to 9000 V m-1 applied DC voltage. The applied electric fieldresulted in increased filament velocity and oriented actin movement, with leading heads of filaments directed towardsthe positive electrode. Velocity (v) was found to increase moderately with electric field strength at applied fields up to~ 4500 V m~（-1） (Δv/ΔE = 0.037 μm~2 V~（-1）sec~（-1）), and then increased at a more rapid rate (Δv/ΔE = 0.100 μm~2 V-1sec~(-1)) athigher field strengths up to 9000 V m-1. The electrophoretic effect caused up to 70% of actin motion to be orientedwithin 30 degrees of the positive electrode, with the largest effect observed using an applied field of 6000 V m~(-1).Higher electric field strengths caused filament breakage.