Enzyme Specificity and Mechanisms at A Molecular Level

Linderman, Russell

Abstract

An investigation of enzyme mechanism at the molecular level by structure-activity studies and 19F-NMR spectral analysis of enzyme/inhibitor complexes is proposed. The synthesis of a structurally diverse series of acyclic and cyclic unsaturated carbonyl compounds will be accomplished by conventional olefination chemistry and by organometallic methodology. These compounds will be used as substrates for the study of the specificity and stereoselectivity of enzymatic glutathione conjugation reactions. New synthetic methods for the preparation of trifluoromethyl ketones will be explored. These procedures will then be applied in the preparation of specific inhibitors for acetylcholinesterase (AChE) and carboxylesterase (CE). Unsaturated trifluoromethyl ketones will also be prepared and assayed as substrates for glutathione-S-transferase catalyzed conjugation reactions. The use of 19F-NMR in this investigation will provide further insight into the mode of action of these important enzymes, and potentially reveal some information as to the structural features at or near the enzyme active site. These enzymes, AChE, CE and glutathione- S-transferase, are all involved in the mechanism of action of pesticides, either in the toxic response or in metabolic detoxification processes. A greater knowledge of the chemical processes catalyzed by these enzymes and of the substrate specificity for each enzyme will allow the development of more specific insecticides, thereby decreasing the mammalian toxicity. This information can also be applied to future pharmaceutical research in the design and synthesis of specific, highly effective enzyme inhibitors. A method for the asymmetric synthesis of alpha- amino trifluoromethyl ketones, needed in the 19F-NMR studies, is also proposed, This synthetic procedure will undoubtably find future application in the development of new pharmaceutical agents.