nanosurface 2007-12-11 02:19
ACS Nano Picks 02: How to take out the trash and keep the motor running
By Prof. [color=Blue]Henry Hess[/color]
University of Florida
Article Title: An improved autonomous DNA nanomotor
Article Citation: [b][i]Nano Letters[/i][/b], 2007, [b]7[/b](9):2574-2577
[b]Article Review:[/b]
DNA nanomotors consume chemical fuel, specifically DNA or RNA strands, and generate exhaust products, such as fragments of fuel strands. After multiple injections of fuel strands, exhaust products start to accumulate and poison the system. Bishop and Klavins remove the products by digesting them further with RNase H and thereby maintain a smoothly running motor. In a sense, the RNase H plays the role of the motor oil in a car engine, and just as motor oil is added to fuel in a two-stroke engine, Bishop adds RNase H to his RNA fuel.
Similar regenerating systems have been widely employed in biochemical and biophysical experiments with motor proteins [Wettermark et al., Anal. Biochem. 22, 211 (1968)], where the exhaust product ADP has to be converted back into ATP. Both approaches demonstrate the need to engineer auxiliary systems to make nanomachines work reliably. An additional, interesting aspect of Bishop’s work is a sketch describing the application of engineering control theory to this molecular robotics problem.