Molecular Shuttles based on Motor Proteins
aDepartment of Bioengineering, University of Washington
Seattle, WA 98195 USA
bMax Planck Institute of Molecular Cell Biology and Genetics
This is an abstract
for a presentation given at the
Foresight Conference on Molecular Nanotechnology.
There will be a link from here to the full article when it is
available on the web.
Active transport in cells, utilizing molecular motors like kinesin and myosin , provides the inspiration for the application of molecular shuttles, nanoscale machines functionally equivalent to trains or conveyor belts. Hybrid devices, employing motor proteins extracted from cells in a synthetic environment, are the first prototypes of molecular shuttles until the development of superior synthetic motors succeeds. The key problems for the construction of a molecular shuttle are guiding the direction of the motion, controlling the speed, and loading and unloading of cargo . Various techniques, relying on surface topography and chemistry [3,4,5] as well as flow fields  and electric fields , have been developed to guide the movement of molecular shuttles on surfaces. Our approach employs micronscale topographical and chemical patterns to achieve effective guiding. Control of the ATP concentration, acting as fuel supply for the motor proteins, can serve as a means to choose the speed of movement. By controlling the ATP concentration in space and time we can move shuttles in separate groups. The loading process requires the coupling of cargo to the shuttle, ideally by a strong and specific link. The bond between biotin (connected to the shuttle) and streptavidin (connected to the cargo) can be utilized to tether cargo to a shuttle. Brownian motion strongly influences the rate of formation and stability of this bond. As potential applications of molecular shuttles sensors, self-healing materials, molecular sorters and nanoscale actuators have been mentioned. Active transport based on motor proteins can bridge passive transport by diffusion and active transport by fluid flow, and it can provide nanometer positional control, solving the problem of “big fingers”. We discuss in detail the scaling behavior of different transport processes, and evaluate their feasibility for different tasks on the Nanoscale.
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Department of Bioengineering, University of Washington
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