Nanoscientists and biochemical engineers are starting to play with DNA not as replicating code, but as physical tools for nanoassembly. Researchers at Arizona State University and at New York University have independently come with ways to use DNA as a framework upon which to build sophisticated molecules. The work has implications for biochemical sensors, drug analysis, even DNA computing. And while the practical applications of these specific techniques are interesting, their larger importance is as a demonstration of the increasing sophistication of our ability to work at the nanoscale.
Arizona State's Hao Yan has developed a way to use DNA as scaffolding for positioning and controlling proteins.
"Rationally-designed DNA nanoscale architectural motifs have for a long time been envisioned as scaffolds for directing the assembly of biomolecules such as proteins into a functional network," said Yan. "However, the methods to control such assemblies are still scarce. A robust and modular approach is needed. "
In his results, Yan and fellow institute researchers Yan Liu, Chenxiang Lin, and Hanying Li have taken advantage of the base pairing properties of DNA to make the DNA nanostructures. By controlling the exact position and location of the chemical bases within a synthetic replica of DNA, Yan could potentially fashion a variety of DNA assemblies. [...] [By] attaching different proteins onto the DNA scaffold, Yan could directly visualize the binding of a drug to its target molecule or recreate metabolic pathways on a single array to mimic the way different organelles function in a cell.
The work is published in the upcoming issue of Angewandte Chemie International.
The research done by Nadrian Seeman and Shiping Liao at New York University is, if anything, more ambitious. They've developed a way of using DNA to assemble complex polymers, with near-term uses in DNA computing. What's particularly novel about their approach is that they managed to get DNA -- normally a scaffolding of complementary bases -- to handle a wider variety of molecules.
The researchers' DNA machine consists of a pair of connected nanomechanical devices that each rotate a pair of wings through half-turns around an axis. The device has four mechanical positions, or states, that are determined by particular instruction, or set, strands of DNA. [...] The molecule assembly technique could eventually be used to construct polymers molecule-by-molecule, he said. "We expect to be able to use the system, or its next version, to include a series of polymers that can be assembled in a particular order."
The technique can be used to encrypt information simply by providing a code that relates a particular sequence to the information it represents.
The technique could be used as an input device for a DNA computer, which could carry out massively parallel computations or control a drug delivery system in the body.
The work appeared originally in the December 17 issue of Science.
This isn't the first time we've talked about nanoassembly and nanoengineering using DNA. We've also addressed Carbon nanotube transistors, "nano-printing" of complex organic molecules, even using non-expressing DNA as identification markers for pathogens. The nano and the bio are increasingly the same field.