With this award, the Chemistry of Life Processes Program in the Chemistry Division of NSF is funding Dr. Reuben Peters from Iowa State University for studies into how certain enzymes catalyze the production of natural products. These natural products have a variety of industrial uses, including as flavors and fragrances. Key roles in the production of these compounds are played by enzymes which typically simply insert an atom of oxygen, but are now known to be capable of much more complex chemical transformations. Several such multi-functional enzymes have been identified in the biosynthetic pathway leading to production of an important plant hormone and these will be studied in detail in this project. The researchers are elucidating how these enzymes accomplish their chemical reactions. The project has clear biotechnological relevance, as one of the enzymes targeted has already drawn interest for use in the production of natural sweeteners. Additionally the graduate and undergraduate students participating in this work are gaining expertise in cutting-edge studies of enzymes with industrial relevance. Finally the inclusion of high-school science teachers extends the reach of this project to the K-12 community.
This project investigates cytochromes P450 (CYPs), which are heme-thiolate mono-oxygenases that generally catalyze hydroxylation, but are capable of much more complex reactions. This can be seen in biosynthesis of gibberellin (GA), a phytohormone whose effect on plant-microbe interactions has led to the independent evolution of GA biosynthesis in plant-associated microbes, including bacteria, from which the relevant multi-functional CYPs have been recently identified. These soluble enzymes are amendable to more detailed investigations. Through these studies, the reaction mechanisms and enzymatic structure-function relationships of the multi-functional CYPs from bacterial GA biosynthesis are being elucidated, furthering understanding of how the basic CYP catalytic cycle is modified to accomplish more complex/unusual reactions, which is currently one of the outstanding questions in enzymology/bioinorganic chemistry, with clear biotechnological implications.
