We wish to understand, on a molecular level, enzyme catalysis in which molecular oxygen is cleaved and incorporated into organic substrates. These reactions represent the major route of incorporation of oxygen into cellular molecules and as such perform essential metabolic functions in both prokaryotic and eukaryotic organisms. Moreover, the oxygenase enzymes actively metabolize molecules which impact on both human health and the world environment. We have chosen for study a representative group of iron containing di- and mono-oxygenases which include protocatechuate dioxygenases, catechol dioxygenases and cytochrome P450. We are using the systematic application of diverse techniques to describe mechanisms at every level of protein structure; these include: optical, ENDOR, EPR, NMR and Mossbauer spectroscopy; chemical modification, amino acid sequence determination and synthesis of transition state analogs; low temperature, steady state and presteady state kinetics. Our goals are 1) to formulate reasonable and defensible mechanisms for oxygenases at the molecular level, 2) to identify the form of oxygen which reacts with substrates, 3) to understand the role of iron in these metalloproteins, 4) to understand the bearing on catalysis of protein interactions with other proteins, solvent and membranes.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM024689-08
Application #
3272448
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1978-01-01
Project End
1988-12-31
Budget Start
1985-01-01
Budget End
1985-12-31
Support Year
8
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Type
Schools of Medicine
DUNS #
168559177
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Meier, Katlyn K; Rogers, Melanie S; Kovaleva, Elena G et al. (2016) Enzyme Substrate Complex of the H200C Variant of Homoprotocatechuate 2,3-Dioxygenase: Mössbauer and Computational Studies. Inorg Chem 55:5862-70
Kovaleva, Elena G; Rogers, Melanie S; Lipscomb, John D (2015) Structural Basis for Substrate and Oxygen Activation in Homoprotocatechuate 2,3-Dioxygenase: Roles of Conserved Active Site Histidine 200. Biochemistry 54:5329-39
Knoot, Cory J; Purpero, Vincent M; Lipscomb, John D (2015) Crystal structures of alkylperoxo and anhydride intermediates in an intradiol ring-cleaving dioxygenase. Proc Natl Acad Sci U S A 112:388-93
Rivard, Brent S; Rogers, Melanie S; Marell, Daniel J et al. (2015) Rate-Determining Attack on Substrate Precedes Rieske Cluster Oxidation during Cis-Dihydroxylation by Benzoate Dioxygenase. Biochemistry 54:4652-64
Meier, Katlyn K; Rogers, Melanie S; Kovaleva, Elena G et al. (2015) A Long-Lived Fe(III)-(Hydroperoxo) Intermediate in the Active H200C Variant of Homoprotocatechuate 2,3-Dioxygenase: Characterization by Mössbauer, Electron Paramagnetic Resonance, and Density Functional Theory Methods. Inorg Chem 54:10269-80
Fielding, Andrew J; Lipscomb, John D; Que Jr, Lawrence (2014) A two-electron-shell game: intermediates of the extradiol-cleaving catechol dioxygenases. J Biol Inorg Chem 19:491-504
Lipscomb, John D (2014) Life in a sea of oxygen. J Biol Chem 289:15141-53
Su, Shengchang; Panmanee, Warunya; Wilson, Jeffrey J et al. (2014) Catalase (KatA) plays a role in protection against anaerobic nitric oxide in Pseudomonas aeruginosa. PLoS One 9:e91813
Yin, DeLu Tyler; Purpero, Vince M; Fujii, Ryota et al. (2013) New structural motif for carboxylic acid perhydrolases. Chemistry 19:3037-46
Hayden, Joshua A; Farquhar, Erik R; Que, Lawrence et al. (2013) NO binding to Mn-substituted homoprotocatechuate 2,3-dioxygenase: relationship to Oýýý reactivity. J Biol Inorg Chem 18:717-28

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