Constructing nanomechanical devices powered by biomolecular motors

A confluence in scientific advancements associated with molecular biology and nanofabrication technology now offers the potential of engineering functional hybrid organic/inorganic nanomechanical systems. Our objectives were to: (i) establish a system for producing a recombinant biomolecular motor; (ii) precisely position and orient biological molecules on nanofabricated substrates; and (iii) acquire baseline performance data on a biomolecular motor in a hybrid system. A recombinant expression system was established for the large-scale production of a thermostable biomolecular motor, F₁-ATPase, modified to contain chemically active `handles.' His tags were used to specifically attach, as well as precisely position and orient, biological molecules on nickel, copper and gold substrates created using electron beam lithography. Further, these substrates were used to attach F₁-ATPase and acquire baseline performance data on motor rotation through the attachment of fluorescent microspheres to the tip of the γ subunit. Counterclockwise rotation of the γ subunit was measured at approximately 10 Hz (3-4 rev s^-1) using a differential interferometer. These data have established several prerequisite technologies that are essential to the integration of biomolecular motors in nano-electro-mechanical systems. The evolution of these technologies will open the door to the seamless integration of the motive power of life with engineered nanofabricated devices.