Aldose and aldehyde reductase are members of the aldo-keto reductase superfamily, and the former is implicated in the pathogenesis of diabetic cataracts, retinopathy, neuropathy and nephropathy. Aldose reductase inhibitors, proposed for the prevention an therapy of these diabetic complications, are not specific and inhibit these two enzymes as well as well as other members of the superfamily. Our objectives are to compare the atomic structure of both aldose and aldehyde reductase enzymes as well as their catalytic and specific operational mechanisms. We seek a better understanding of the enzymatic mechanism in order to rationally develop highly specific inhibitors unique to each enzyme. We propose to: 1) Determine and compare the atomic structure, cofactor and inhibitor binding, and catalytic mechanisms of human aldose and aldehyde reductase using site-directed mutagenesis, functional evaluation and structure determination by x-ray crystallography; 2) Determine and compare the reaction sequence, rate-limiting steps of the two enzymes by primary isotope effect studies, and the pre-steady state rate constants by stopped-flow measurements; 3) Investigate the function and control of the NADPH holding loop in cofactor exchange and the role of the C-terminal loop in determining substrate specificities; and 4) Characterize athe binding of inhibitors to the active sites of both enzymes, and use the information obtained in these studies to design specific inhibitors of both enzymes, using computer modelling, organic solvent mapping of enzyme surface, peptidomimetic compounds and knowledge of the mechanistic pathways.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY011018-03
Application #
2430389
Study Section
Visual Sciences C Study Section (VISC)
Project Start
1995-06-01
Project End
1998-05-31
Budget Start
1997-06-01
Budget End
1998-05-31
Support Year
3
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Pediatrics
Type
Schools of Medicine
DUNS #
074615394
City
Houston
State
TX
Country
United States
Zip Code
77030
Bohren, Kurt M; Brownlee, June M; Milne, Amy C et al. (2005) The structure of Apo R268A human aldose reductase: hinges and latches that control the kinetic mechanism. Biochim Biophys Acta 1748:201-12
Barski, Oleg A; Siller-Lopez, Fernando; Bohren, Kurt M et al. (2004) Human aldehyde reductase promoter allows simultaneous expression of two genes in opposite directions. Biotechniques 36:382-4, 386, 388
Barski, Oleg A; Papusha, Victor Z; Kunkel, Gary R et al. (2004) Regulation of aldehyde reductase expression by STAF and CHOP. Genomics 83:119-29
Gabbay, Kenneth H (2004) Aldose reductase inhibition in the treatment of diabetic neuropathy: where are we in 2004? Curr Diab Rep 4:405-8
Sheikh-Hamad, D; Nadkarni, V; Choi, Y J et al. (2001) Cyclosporine A inhibits the adaptive responses to hypertonicity: a potential mechanism of nephrotoxicity. J Am Soc Nephrol 12:2732-41
Bohren, K M; Grimshaw, C E (2000) The sorbinil trap: a predicted dead-end complex confirms the mechanism of aldose reductase inhibition. Biochemistry 39:9967-74
Barski, O A; Gabbay, K H; Bohren, K M (1999) Characterization of the human aldehyde reductase gene and promoter. Genomics 60:188-98
Nadkarni, V; Gabbay, K H; Bohren, K M et al. (1999) Osmotic response element enhancer activity. Regulation through p38 kinase and mitogen-activated extracellular signal-regulated kinase kinase. J Biol Chem 274:20185-90
Harrison, D H; Bohren, K M; Petsko, G A et al. (1997) The alrestatin double-decker: binding of two inhibitor molecules to human aldose reductase reveals a new specificity determinant. Biochemistry 36:16134-40
Ko, B C; Ruepp, B; Bohren, K M et al. (1997) Identification and characterization of multiple osmotic response sequences in the human aldose reductase gene. J Biol Chem 272:16431-7

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