Manganese active sites play a key role in oxygen membolism through participation in superoxide and peroxide defense mechanisms, oxygen activation chemistry, and dioxygen biosynthesis. In contrast to the relatively well-studied Fe and Cu complexes involved in oxygen chemistry, an sites are just beginning to be studied in details and the most effective probes have yes to be defined. We plan to systematically develop a combination of powerful spectroscopic approaches including optical absorption, CD and low temperature MCD over the UV-VlS-near IR spectral range complemented by EPR and SQUID susceptibility measurements to explore the Sround and excited sites of biological in complexes and probe small molecule interactions with these active sites. Our initial focus will be on detailed spectroscopic studies of the mononuclear site in on SD and the binuclear Mn cluster in Mn pseudocatalase, in all their accessible redox sites and with exogenous ligand perturbations. Parallel studied on inorganic models will complement the studied of manganoenzymes, providing valuable spectral calibration and a basis for evaluating the information confined in the spectra of the biological complexes. Manganese coordination complexes representing each of the key oxidation statues in limiting geometries for both ononuclear and binuclear Mn will be prepared and analyzed using the combination of spectroscopies approach for maximum resolution of the d-->d and charge transfer spectra. This rich spectral information will be interpreted using powerful methods of ligand field theory, leading to a description of the metal ions and their ligand interactions in electronic structural detail. Key insights developed in the initial studies on this set of relatively simple and well defined Mn centers will be extended to the binuclear Mn active site in Mn-dependent ribonucleotide reductase and the photosynthetic 02-evolving site, providing information on the structures and ligand interactions in these important and interesting active sites.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM042680-03
Application #
3301464
Study Section
Metallobiochemistry Study Section (BMT)
Project Start
1989-07-01
Project End
1993-06-30
Budget Start
1991-07-01
Budget End
1992-06-30
Support Year
3
Fiscal Year
1991
Total Cost
Indirect Cost
Name
Carnegie-Mellon University
Department
Type
Schools of Arts and Sciences
DUNS #
052184116
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Whittaker, James W (2016) Intracellular trafficking of the pyridoxal cofactor. Implications for health and metabolic disease. Arch Biochem Biophys 592:20-6
Whittaker, Mei M; Penmatsa, Aravind; Whittaker, James W (2015) The Mtm1p carrier and pyridoxal 5'-phosphate cofactor trafficking in yeast mitochondria. Arch Biochem Biophys 568:64-70
Coates, Christopher S; Milikisiyants, Sergey; Chatterjee, Ruchira et al. (2015) Two-dimensional HYSCORE spectroscopy of superoxidized manganese catalase: a model for the oxygen-evolving complex of photosystem II. J Phys Chem B 119:4905-16
Whittaker, Mei M; Whittaker, James W (2014) Expression and purification of recombinant Saccharomyces cerevisiae mitochondrial carrier protein YGR257Cp (Mtm1p). Protein Expr Purif 93:77-86
Whittaker, James W (2013) Cell-free protein synthesis: the state of the art. Biotechnol Lett 35:143-52
Whittaker, Mei M; Whittaker, James W (2012) Metallation state of human manganese superoxide dismutase expressed in Saccharomyces cerevisiae. Arch Biochem Biophys 523:191-7
McConnell, Iain L; Grigoryants, Vladimir M; Scholes, Charles P et al. (2012) EPR-ENDOR characterization of (17O, 1H, 2H) water in manganese catalase and its relevance to the oxygen-evolving complex of photosystem II. J Am Chem Soc 134:1504-12
Whittaker, Mei M; Lerch, Thomas F; Kirillova, Olga et al. (2011) Subunit dissociation and metal binding by Escherichia coli apo-manganese superoxide dismutase. Arch Biochem Biophys 505:213-25
Whittaker, James W (2011) Non-heme manganese catalase - The 'other' catalase. Arch Biochem Biophys :
Whittaker, James W (2010) Metal uptake by manganese superoxide dismutase. Biochim Biophys Acta 1804:298-307

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