Biomimetic Polymeric Catalysis in Water

Columbia University, New York NY

Investigators

Abstract

With the support of the Organic Dynamics Program in the Chemistry Division, Professor Ronald Breslow of Columbia University will perform research that will greatly improve the properties of artificial enzymes adding to our understanding of the factors that make enzymes effective while producing information that can lead to the creation of better catalysts for important synthetic reactions. This work will help make it clear how reactions in water can use the hydrophobic effect to promote rate and selectivity while avoiding the rate-slowing effect that water can impose by hydrogen bonding to catalytic acids and bases and substrate groups. Professor Breslow will extend his preliminary published work, done under the previous grant, in which the coenzyme mimic pyridoxamine is attached in the interior of a synthetic polyamine. Hydrocarbon chains will also be incorporated into the polymer to produce a hydrophobic interior to this "artificial enzyme." It was recently found that a 240,000-fold acceleration of the synthesis of tryptophan with this enzyme mimic in water could be achieved, compared with pyridoxamine itself in water. Effects that were observed were sorted into rate and binding terms, and contrasting effects of the attached hydrocarbon chains were seen. One of the goals of this work is to develop a program to understand the role that various polymers or oligomers play in enzyme mimics. The Organic and Macromolecular Chemistry Program supports Professor Ronald Breslow of Columbia University who will attempt to show how the invention of practical synthetic methods that function in water solution will be environmentally friendly, and in many ways more convenient than traditional organic solvents. Industry may adopt the catalysts invented, or some extensions thereof, and biochemists and students will learn general principles from the findings of this work. The investigation of enzyme mimics will aid in our understanding of how these complex biological catalysts function and perhaps point the way to the development of new and more efficient methodology.