Mossbauer studies are proposed for the following enzymes: (1) hydrogenases from Clostridium pasteurianum W5 and from sulfate-reducing bacteria, (2) nitride reductase from Thiobacillus denitrificans, and (3) sulfite reductases from T. denitrificans and sulfate-reducing bacteria. Hydrogenase is capable of activating molecular hydrogen and many micro-organisms use it to metabolize H2. Understanding the hydrogenase mechanism could be a key step toward catalysis of hydrogen production from water and solar energy, a potentially important alternate energy source. Nitrite reductase reduces nitrite to nitric oxide, while sulfite reductase catalyzes the 6-electron reduction of sulfite to sulfide. These reductions of nitrite and sulfite are, respectively, essential steps in nitrate and sulfate respirations. Despite the importance of these enzyme's biological functions, their prosthetic groups are poorly understood. The proposed studies should reveal physical properties and structural information pertinent to the prosthetic groups of these enzymes; information essential to the understanding of their respective mechanisms. The results will be correlated with EPR, NMR, ENDOR, and optical data, and hopefully will provide a sound experimental basis for detailed physical models of the prosthetic groups.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Modified Research Career Development Award (K04)
Project #
5K04DK001135-04
Application #
3072296
Study Section
Metallobiochemistry Study Section (BMT)
Project Start
1983-09-01
Project End
1988-08-31
Budget Start
1986-09-01
Budget End
1987-08-31
Support Year
4
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Emory University
Department
Type
Schools of Arts and Sciences
DUNS #
042250712
City
Atlanta
State
GA
Country
United States
Zip Code
30322
Lampreia, J; Moura, I; Teixeira, M et al. (1990) The active centers of adenylylsulfate reductase from Desulfovibrio gigas. Characterization and spectroscopic studies. Eur J Biochem 188:653-64
Kretchmar, S A; Teixeira, M; Huynh, B H et al. (1988) Mossbauer studies of electrophoretically purified monoferric and diferric human transferrin. Biol Met 1:26-32