Liu's team first applied DNA-templated synthesis to the creation of new synthetic molecules; now, shifting their focus a bit, they're using the technique to reveal as-yet undiscovered chemical reactions. DNA's inherent sequence selectivity - binding only to other strands with a complementary sequence - means that DNA-templated synthesis can be used to evaluate hundreds of potential chemical reactions simultaneously, in a single solution.

"We had assumed that DNA-templated synthesis might make possible rapid discovery of potentially useful reactions and were encouraged to find, early on, an unexpected reaction that efficiently coupled two simple hydrocarbons, a terminal alkyne and a terminal alkene, to form a useful and more complex group called a trans-enone," Liu says. "We've also been excited by the fact that this reaction not only works in the DNA-templated format in which it was discovered, but also in a conventional flask-based chemistry format."

Chemical synthesis occurs very differently in laboratories and in cells. Chemists typically work with molecules that react to form products when they randomly collide at high concentrations. By contrast, biomolecules are found within cells at concentrations that are often a million times lower than the concentrations of molecules in laboratory reactors. In nature, the reactions between these highly dilute molecules are directed by enzymes that selectively bring certain biological reactants together. Liu and his colleagues use DNA as a similar type of intermediary to bring together synthetic small molecules that are otherwise too dilute to react, allowing minute quantities of sparse molecules to behave as denser mixtures when assembled together by
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Contact: Steve Bradt
steve_bradt@harvard.edu
617-496-8070
Harvard University
29-Sep-2004