POSITIONING OF FILAMENTS TO FACILITATE UNHINDERED MOTILITY EXPEIMENTS

A schematic depicting a molecular motor carrying a polystyrene bead cargo along actin filament suspended between two metallic electrodes.
 

Actin filament suspended between two electrodes and digitized, instantaneous image

PIs: M. Arsenault, M. Riegelman, Y. Goldman, & H. H. Bau (University of Pennsylvania) and J. Sellers (NIH)

• Most motility experiments are carried out with filaments immobilized to a surface. This arrangement hinders the filament’s motion and prevents the motor from twisting around the filament. Thus, the laboratory experiments do not fully represent in vivo conditions. Furthermore, we are interested in providing a long track for motility experiments with ultraprocessive mutated motors.
  
  
• We patterned a pair of electrodes on glass substrates, etched a groove in the gap between the electrodes, and used dilectrophoretic nano-positioning to place actin filaments across the electrodes. The motion of the filaments was imaged, digitized, and their modes of vibrations are being analyzed.
  
  
• Hydrophobic coatings were patterned on surfaces using micro-printing techniques to position actin filaments at pre-determined patterns such as “loops” to form an “infinite” tarck.

Methods were developed to form filaments to desired shapes and to position the filaments at pre-determined locations including suspended forms unhindered by surfaces

Reference: Riegelman, M., Liu, H., and Bau, H. H., 2006, Controlled Nano-Assembly and Construction of Nanofluidic Devices, J. Fluid Engineering 128, 6-13.

Actin filament forms a “closed,” infinite track