Actomyosin-driven motility on patterned polyelectrolyte mono- and multilayers

Positive polyelectrolytes were investigated as new surface coatings for promoting in vitro actomyosin motility. Two surface arrangements were studied: a monolayer of the polyelectrolyte PAH, poly(allylamine hydrochloride), and multilayers consisting of 11-41 layers of alternating polypositive PAH/polynegative PSS (polystyrene sulfonate) electrolytes. For in vitro motility assays, rabbit skeletal muscle heavy meromyosin (HMM) was applied to the PAH surface of the polyelectrolyte mono/multilayer. Myosin-driven motion of actin filaments labeled with rhodamine-phalloidin was recorded at 30degreesC using epifluorescence microscopy. Actin filaments were found to have a mean speed of 2.9 +/- 0.08 mum/sec on the multilayer surface compared to 2.5 +/- 0.06 mum/sec on the monolayer surface. Average filament length and speed increased when nonionic surfactant was added to HMM and ionic strength of the motility buffer increased, respectively. Microcontact printing with a water-insoluble charged block copolymer on PAH produced patterned surfaces that restricted filament motion to PAH tracks.