Nanokinematic Devices & Systems

Group: WVU: Famouri, Hornak (CSEE), Gannett (Pharmacy), Timperman, Carroll (Chem) and Wu (MAE).

Research Experiences: Motility assay stability and control, imaging, proteins in a non-cellular environment.

Actin-Myosin Transport: Biomolecular transport of molecular cargoes has the potential to enable addressing of the surface of integrated recognition systems not attainable with microfluidics. Protein-based systems being explored as a means of realizing nanoscale transport mechanisms include linear and rotary biomolecular motors. Here, proteins are used to transport other biomolecules by applying electrical or other signals. The actin-myosin system is an excellent candidate for the study of protein-based linear biomolecular motor systems due to its motor properties and because the myosin tail itself contains binding sections which could be exploited for cargo attachment. In this system the myosin motor heads drive specific polymer filaments made up of protein monomers (actin) utilizing ATP as a chemical energy source. Harnessing the motion of this biomolecular system to achieve addressable molecular motility functions requires actuation rate control, directional control, cargo attachment to filament or motor molecules, and the viability of the proteins in a non-cellular environment. Moreover, as these biomolecular transport systems evolve and mature, it is critical that the interface be established between their nanoscale motion and the chip-level microelectronic environment that will enable reconfigurable control of their nanoscale motion via electronic signals.

We will examine the use of discrete electrical fields localized on the micron scale as a means of regulating the transport characteristics of linear biomolecular motor systems over discrete chip locations. Figure 1 illustrates our ability to construct and examine an actin-myosin based linear biomolecular system. Building on these initial efforts, we will investigate the interaction of electric fields on this biomolecular motor system, using integrated electrode structures under the assayed surface.

Along with the necessity of ATP to fuel movement, the preservation of myosin activity requires that specific temperature, pH and ionic strength conditions be maintained. Attesting to the importance of myosin in cellular function, nature has devised many exquisitely designed myosin molecules that are able to operate under a wide variety of environmental conditions ranging from extreme heat, acidity and hypoxia. To exploit this diversity we are isolating myosin from organisms accustomed to survival in harsh environments. Cell culture using plates and/or bioreactors along with myosin isolation will be accomplished using standard methods where appropriate. SDS-PAGE along with determination of ATPase activity and electron microscopy will be employed to determine purity and enzyme functionality. As necessary, standard myosin isolation protocols will be modified, or alternatively, new methods developed.

Once purified, the REU participants will learn to test the myosins within the chip biomolecular motors platform. Manipulation of fields will be used to experimentally characterize their effect on linear biomolecular motor filament alignment and motion. Assay ambient fluorescence techniques will be used to optically observe actin motion and mass spectrometry will be utilized to determine field effects on the integrity of the actin and myosin. s of the flow through nanofluidic channels.