We propose to study how protein environment and/or chromophore interaction controls the properties and reactivity of a chromophore using resonance Raman spectroscopy by examining siroheme and iron-sulfur clusters in different sulfite reductases from sulfate reducing bacteria. Resonance Raman spectroscopy can yield detailed molecular information of the chromophore in situ unavailable by other methods. Sulfite reductases catalyze the 6-electron reduction of sulfite to sulfide. The reduction is crucial for synthesis of sulfur-containing cell constituents and in terminal respiration for sulfate reducing bacteria. Although sulfite reductases contain the same two chromophores, their properties are quite different, making them ideal systems for studying structural changes with reactivity. In order to understand the Raman spectra of the chromophores, we plan to study the chromophores and their analogs in various solutions and environments. We also propose to study the mechanism of sulfite reductases by examining changes in the chromophores during catalysis, at different redox potentials, and bound to different substrates. We also propose to characterize the chromophores of other iron- sulfur proteins from sulfate reducing bacteria.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
1R29GM038555-01
Application #
3466307
Study Section
Biophysics and Biophysical Chemistry B Study Section (BBCB)
Project Start
1987-07-01
Project End
1992-06-30
Budget Start
1987-07-01
Budget End
1988-06-30
Support Year
1
Fiscal Year
1987
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
Underwood-Lemons, T; Moura, I; Yue, K T (1993) Resonance Raman study of sirohydrochlorin and siroheme in sulfite reductases from sulfate reducing bacteria. Biochim Biophys Acta 1157:275-84
Zhelyaskov, V; Yue, K T (1992) A Raman study of the binding of Fe(III) to ATP and AMP. Biochem J 287 ( Pt 2):561-6
Gray, T A; Yue, K T; Marzilli, L G (1991) Effect of N-alkyl substituents on the DNA binding properties of meso-tetrakis (4-N-alkylpyridinium-4-yl)porphyrins and their nickel derivatives. J Inorg Biochem 41:205-19
Yue, K T; Lee, M; Zheng, J et al. (1991) The determination of the pKa of histidine residues in proteins by Raman difference spectroscopy. Biochim Biophys Acta 1078:296-302
Lai, K K; Moura, I; Liu, M Y et al. (1991) Direct evidence of the metal-free nature of sirohydrochlorin in desulfoviridin. Biochim Biophys Acta 1060:25-7
Gu, H H; Gallagher, M J; Rupkey, S et al. (1990) Gene and derived peptide sequences for C. tropicalis vacuolar ATPase subunit b. Nucleic Acids Res 18:7446