Enzymes that catalyze the synthesis, utilization, and interconversion of phosphorylated-metabolites usually require specific activation by inorganic cations, and reactions involving metal nucleotide substrates or effectors are of central importance in a wide varity of cellular processes. Understanding the roles of metal ions in the respective catalytic activations, and in the overall mechanisms for these reactions requires detailed information on the binding interactions that occur between the metal ion, substrates, and protein in the reactive complexes. The goals of this project are to determine the coordination schemes in enzyme-metal ion-substrate and inhibitor complexes in order to understand the relationships between specific binding interactions and chemical activation of these molecules and the strategies that are exploited in the catalytic mechanisms. The proposed research will use electron paramagnetic resonance, nuclear magnetic resonance, and vibrational spectroscopy, together with isotopically labeled molecules (substrates and analogue), to determine the binding schemes between metal ion, substrate and protein at the active sites of several enzymes that catalyze phosphotransfer reactions. The experiments will also provide information on the stereospecificities of enzyme active sites and on the mode of action of specific inhibitory compounds. Knowledge of the structures of enzyme-substrate complexes is essential to the rational design of specific inhibitors that can be used as therapeutic agents, or as biochemical and physiological reagents to control, selectively, reactions or metabolic pathways. The information is also of fundamental importance in understanding the mechanisms for biological catalysis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM035752-05
Application #
3288906
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1986-01-01
Project End
1990-12-31
Budget Start
1990-01-01
Budget End
1990-12-31
Support Year
5
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of Wisconsin Madison
Department
Type
Other Domestic Higher Education
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
Tang, Kuo-Hsiang; Mansoorabadi, Steven O; Reed, George H et al. (2009) Radical triplets and suicide inhibition in reactions of 4-thia-D- and 4-thia-L-lysine with lysine 5,6-aminomutase. Biochemistry 48:8151-60
Carmieli, Raanan; Larsen, Todd M; Reed, George H et al. (2007) The catalytic Mn2+ sites in the enolase-inhibitor complex: crystallography, single-crystal EPR, and DFT calculations. J Am Chem Soc 129:4240-52
Sims, Paul A; Menefee, Ann L; Larsen, Todd M et al. (2006) Structure and catalytic properties of an engineered heterodimer of enolase composed of one active and one inactive subunit. J Mol Biol 355:422-31
Poyner, Russell R; Anderson, Mark A; Bandarian, Vahe et al. (2006) Probing nitrogen-sensitive steps in the free-radical-mediated deamination of amino alcohols by ethanolamine ammonia-lyase. J Am Chem Soc 128:7120-1
Mansoorabadi, Steven O; Seravalli, Javier; Furdui, Cristina et al. (2006) EPR spectroscopic and computational characterization of the hydroxyethylidene-thiamine pyrophosphate radical intermediate of pyruvate:ferredoxin oxidoreductase. Biochemistry 45:7122-31
Mansoorabadi, Steven O; Padmakumar, Rugmini; Fazliddinova, Nisso et al. (2005) Characterization of a succinyl-CoA radical-cob(II)alamin spin triplet intermediate in the reaction catalyzed by adenosylcobalamin-dependent methylmalonyl-CoA mutase. Biochemistry 44:3153-8
Reed, George H; Mansoorabadi, Steven O (2003) The positions of radical intermediates in the active sites of adenosylcobalamin-dependent enzymes. Curr Opin Struct Biol 13:716-21
Sims, Paul A; Larsen, Todd M; Poyner, Russell R et al. (2003) Reverse protonation is the key to general acid-base catalysis in enolase. Biochemistry 42:8298-306
Poyner, Russell R; Larsen, Todd M; Wong, Se-Wei et al. (2002) Functional and structural changes due to a serine to alanine mutation in the active-site flap of enolase. Arch Biochem Biophys 401:155-63
Frey, Perry A; Chang, Christopher H; Ballinger, Marcus D et al. (2002) Kinetic characterization of transient free radical intermediates in reaction of lysine 2,3-aminomutase by EPR lineshape analysis. Methods Enzymol 354:426-35

Showing the most recent 10 out of 40 publications