Two approaches are proposed to investigate the structure-function relationships responsible for ligand binding affinities and catalytic mechanisms of two different enzymes, T4 bacteriophage dihydrofolate reductase (T4 DHFR) and citrate synthase (CS). The first will be a crystallographic analysis of the structures of the enzymes, a comparison of these structures in terms of ligand affinities and catalytic activity and a further comparison with known structures of distantly related or mutant forms of the enzymes. The second approach will involve an investigation of the role of electrostatic fields in these enzymes. Dihydrofolate reductase catalyzes a reaction in a cyclic pathway essential to DNA synthesis. In particular, it is highly susceptible to inhibition by synthetic folate compounds, showing high species selectivity. These compounds are of considerable interest for the control of rapidly dividing cells. Citrate synthase catalyzes the condensation of oxaloacetate and acetylCoenzyme A to form citrate and Coenzyme A. It is one of a few enzymes capable of directly forming a carbon-carbon bond. It presents an unprecedented opportunity to examine an unusual mechanism which probably involves sequential conformational changes and electrostatic destabilization of substrate.***//

Agency
National Science Foundation (NSF)
Institute
Division of Molecular and Cellular Biosciences (MCB)
Application #
8817438
Program Officer
Arthur Kowalsky
Project Start
Project End
Budget Start
1989-03-01
Budget End
1992-08-31
Support Year
Fiscal Year
1988
Total Cost
$253,300
Indirect Cost
Name
University of Oregon Eugene
Department
Type
DUNS #
City
Eugene
State
OR
Country
United States
Zip Code
97403