This Research award in the Inorganic, Bioinorganic and Organometallic Chemistry program and the Molecular and Cellular Biology program supports work by Professor Eduardus (Evert) C. Duin at Auburn University, Alabama, to probe the reaction mechanism of the penultimate and ultimate proteins in the 1-deoxy-D-xylulose-5-phosphate (DOXP) pathway, GcpE and LytB, and the role of their active-site iron-sulfur clusters in this process. Kinetic experiments will provide insight in the role of several transient EPR-active species in the reaction mechanisms. The species will be characterized using the combination of EPR/ENDOR spectroscopies and isotopic labeling of selected atoms in the substrate structures. In addition further details on the mechanisms of the enzymes will be obtained through substrate modulation studies. The combined data will provide a complete understanding of the mechanisms of the GcpE and LytB enzymes. Since both enzymes seem to be involved in a completely new type of catalysis this will be an important contribution to the iron-sulfur field. In addition, this knowledge will benefit the commericialization of biotechnology through increased ease of production of commercially interesting isoprenoids and the development of novel herbicides that are less harmful to humans. The funding also supports the Biochemistry division research and teaching efforts through the acquisition of equipment for rapid-mix/rapid freeze studies.
Normal 0 false false false EN-US X-NONE X-NONE Two enzymes in the MEP/DOXP pathway for isoprene synthesis have been studied in detail. In particular, important steps in the conversion of their respective substrates into products have been studied. The MEP/DOXP pathway is found in a large group of pathogeneic bacteria and parasites. Understanding of how the enzymes function gives clues on how to develop new drugs that can kill these organisms and cure the disseases they cause. These include malaria, tuberculosis, plague, and stomach ulcers. Our main contribution to this field is that we have been able to trap and study several reaction intermediates. In both enzymes, IspH and IspG, it was shown that the substrate binds directly to an iron-sulfur cluster that is present in the active site. The electronic and magnetic properties of these species are very unique. Although the enzymes catalyze a similar reaction and the iron-sulfur-based signals are similar too, very different structures have been proposed for these reaction intermediates. These studies gave important clues on how these enzymes work and what types of inhibitors might work as drugs. We now hope to continue our research to further develop these ideas. Normal 0 false false false EN-US X-NONE X-NONE
