Sugars in their open chain conformations are prone to enolization and subsequent autoxidation that yields 1,2 - dicarbonyls capable of covalently modifying proteins and nucleic acids. Superoxide (02 ) both initiates and propagates the oxidation of enediols. Glycation of proteins and subsequent oxidation of the resultant E-Amino fructosyl-lysine residues yields a variety of products, including 1, 2-dicarbonyls. This is believed to be responsible for the deleterious consequences of the hyperglycemia of poorly controlled diabetes mellitus. Our goals are: to further elucidate this deleterious interaction of O2 with sugars using Escherichia coli as our model. We will: isolate, sequence, and clone the defensive glyoxalase III (glo III); create mutants defective in glo III and explore their resistance to short chain sugars and to O2 ; create the glo III mutants in the sod A, sod B background, and in the gsh A background and probe how much the lack of SOD and of GSH exacerbates the glo III deficiency; and to use the superoxide dismutase mimic Mn (III) TM-2-PyP to try to alleviate the consequences of these lacks of glo III. We will explore the substrate specificity of Glo III and compare the kinetic parameters of the different substrates. We will try to find competitive inhibitors of Glo III. We will also explore the reason for the extreme sensitivity of Glo III to inactivation by O2 and by H2O2. What we ,learn with E. coli will certainly illuminate the interactions of O2 and sugars in higher organism.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK059868-03
Application #
6607536
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Program Officer
Jones, Teresa L Z
Project Start
2001-09-01
Project End
2005-07-31
Budget Start
2003-08-01
Budget End
2004-07-31
Support Year
3
Fiscal Year
2003
Total Cost
$192,500
Indirect Cost
Name
Duke University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
044387793
City
Durham
State
NC
Country
United States
Zip Code
27705
Liochev, Stefan I; Fridovich, Irwin (2006) The role of CO2 in metal-catalyzed peroxidations. J Inorg Biochem 100:694-6
Batinic-Haberle, Ines; Spasojevic, Ivan; Stevens, Robert D et al. (2006) New PEG-ylated Mn(III) porphyrins approaching catalytic activity of SOD enzyme. Dalton Trans :617-24
Liochev, Stefan I; Fridovich, Irwin (2005) The role of CO2 in cobalt-catalyzed peroxidations. Arch Biochem Biophys 439:99-104
Liochev, Stefan I; Fridovich, Irwin (2004) CO2, not HCO3-, facilitates oxidations by Cu,Zn superoxide dismutase plus H2O2. Proc Natl Acad Sci U S A 101:743-4
Batinic-Haberle, Ines; Spasojevic, Ivan; Stevens, Robert D et al. (2004) New class of potent catalysts of O2.-dismutation. Mn(III) ortho-methoxyethylpyridyl- and di-ortho-methoxyethylimidazolylporphyrins. Dalton Trans :1696-702
Okado-Matsumoto, Ayako; Batinic-Haberle, Ines; Fridovich, Irwin (2004) Complementation of SOD-deficient Escherichia coli by manganese porphyrin mimics of superoxide dismutase activity. Free Radic Biol Med 37:401-10
Liochev, Stefan I; Fridovich, Irwin (2003) Mutant Cu,Zn superoxide dismutases and familial amyotrophic lateral sclerosis: evaluation of oxidative hypotheses. Free Radic Biol Med 34:1383-9
Liochev, Stefan I; Fridovich, Irwin (2003) Reversal of the superoxide dismutase reaction revisited. Free Radic Biol Med 34:908-10
Liochev, Stefan I; Fridovich, Irwin (2003) The mode of decomposition of Angeli's salt (Na2N2O3) and the effects thereon of oxygen, nitrite, superoxide dismutase, and glutathione. Free Radic Biol Med 34:1399-404
Benov, Ludmil; Fridovich, Irwin (2002) Induction of the soxRS regulon of Escherichia coli by glycolaldehyde. Arch Biochem Biophys 407:45-8

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