Click here to login if you're an NAE Member
Recover Your Account Information
The 2011 Charles Stark Draper Prize is awarded to Frances H. Arnold and Willem P. C. Stemmer "for directed evolution, a method used worldwide for engineering novel enzymes and biocatalytic processes for pharmaceutical and chemical products."
At the heart of directed evolution is the concept that the mutation and selection processes that occur in nature can be vastly accelerated in the laboratory to obtain specific, targeted improvements in the function of single proteins and multi-protein pathways. Arnold showed that randomly mutating genes of a targeted protein, especially enzymes, would result in some new proteins having more desirable traits than they did before the mutation. She selected the best proteins and repeated this process multiple times, essentially directing the evolution of the proteins until they had properties desirable for a particular use.
Taking his clues from the classical breeding of plants and animals, Stemmer focused on a different natural process for creating diversity, focusing on the recombination of pre-existing natural diversity, which he called “DNA shuffling.” Instead of causing random mutations, he shuffled the same gene from diverse but related species to create clones which were as good as or better than the parental genes in a given targeted property.
One of the most important aspects of directed evolution is that it allows for a practical and cost-effective way for improving protein function. Previous efforts, particularly those involving a design based on the structures of enzymes and the predicted effects of mutations, were often not successful. They were poor at improving the sought-after complex combinations of properties and were been labor- and cost-intensive,
Their techniques—and several variants—are in wide use, impacting the fields of engineering, chemistry and biochemistry. Directed evolution has been used to find solutions in such areas as food ingredients, pharmaceuticals, toxicology, agricultural products, gene delivery systems, laundry aids, and biofuels, among others.