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nanotimes

News in Brief

Nano-Mechanical Systems //

DNA Construction Kit

T

he research team around Dr. Damian Ackermann and Prof. Michael Famulok

from the Life & Medical Sciences (LIMES) Institute at the University of Bonn, Germany, report in Nature Nanotechnology the design, assembly

and characterization of rotaxanes in which both

the dumb-bell-shaped molecule and the macrocycle are made of double-stranded DNA, and in which the axle of the dumb-bell is threaded through the macro- cycle by base pairing.

But the researchers are not primarily interested in DNA‘s function as a genetic carrier. Rather, their focus of interest lies in using the principles of base- pairing of DNA double-strands for constructing sophisticated architectures at the nanoscale. The double-helix forms a very stable scaffold. Moreover, a part of one strand can be removed at any chosen position to serve as a connecting point for other components of a nanomachine.

“The specificity of individual strands makes DNA highly suitable. It offers us quite a lot of possibilities,” explains Damian Ackermann. “DNA is like a Lego brick, It‘s the ideal material for nano-architecture,” adds Professor Famulok.

The Bonn-based biochemists have created a com- pletely new kind of rotaxane. It forms a stable me- chanical unit, with a freely moving inner hoop. A great deal can be done with this wheel.

© Michael Famulok / Uni Bonn

10-04 :: April 2010

“We envisage quite a few things,” says Professor Famulok. “Our initial aim is to construct systems in which movement can be controlled at the nano- level. The axle and wheels are now available, and we have some ideas for how to get the wheels turning.” These nanoengines might then also be combined with other biological systems, such as proteins.

The researchers now realize that, with their DNA rotaxanes, they have laid the foundations for deve- loping all sorts of different nano-mechanical systems based on mechanically interlocked double-stranded DNA. It remains open what will finally emerge from these efforts, but the important breakthrough has been made

Damian Ackermann, Thorsten L. Schmidt, Jeffrey S. Han- nam, Chandra S. Purohit, Alexander Heckel, Michael Famulok: A double-stranded DNA rotaxane, In: Nature Nanotechnology AOP, April 18, 2010, DOI:10.1038/NN- ANO.2010.65:

http://dx.doi.org/10.1038/NNANO.2010.65