We have identified a novel phosphomonoester fructose 3-phosphate (Fru-3-P) in the diabetic rat lens and shown it to be a potent crosslinking agent of crystallins in vitro. We have also demonstrated that Fru-3-P decomposes to 3-deoxyglucosone (3dG) a potent protein crosslinker, and have shown that this dicarbonyl is present in the diabetic lens. In this research program we propose to further assess the importance of Fru-3-P in the diabetic rat lens by identifying other possible glycating agents in this tissue and to evaluate their glycation potential relative to Fru-3-P. If Fru-3-P turns out to be the dominant glycating agent, as suggested by preliminary data, we will subsequently determine the kinetic parameters of Fru-3-P and 3dG mediated glycation of rat crystallins in vitro and determine the amount glycation mediated by these compounds in the diabetic rat lens in vivo. Since fructose 3-phosphate is synthesized from fructose by a novel enzyme fructose-3-phosphokinase, we will purify this enzyme and determine its molecular identity as well as its kinetic and mechanistic properties.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
2R01EY008414-05A2
Application #
2162266
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1990-01-01
Project End
1998-03-31
Budget Start
1995-04-01
Budget End
1996-03-31
Support Year
5
Fiscal Year
1995
Total Cost
Indirect Cost
Name
Fox Chase Cancer Center
Department
Type
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19111
Szwergold, Benjamin S; Lal, Sundeep (2005) Identification of diadenosine-triphosphate in mature bovine lenses. Biochem Biophys Res Commun 326:718-23
Szwergold, B S; Howell, S; Beisswenger, P J (2001) Human fructosamine-3-kinase: purification, sequencing, substrate specificity, and evidence of activity in vivo. Diabetes 50:2139-47
Lal, S; Randall, W C; Taylor, A H et al. (1997) Fructose-3-phosphate production and polyol pathway metabolism in diabetic rat hearts. Metabolism 46:1333-8
Szwergold, B S; Lal, S; Taylor, A H et al. (1995) 31P-nuclear magnetic resonance evidence of an activated hexose-monophosphate shunt in hyperglycemic rat lenses in vivo. Diabetes 44:810-5
Lal, S; Szwergold, B S; Taylor, A H et al. (1995) Production of fructose and fructose-3-phosphate in maturing rat lenses. Invest Ophthalmol Vis Sci 36:969-73
Lal, S; Szwergold, B S; Taylor, A H et al. (1995) Metabolism of fructose-3-phosphate in the diabetic rat lens. Arch Biochem Biophys 318:191-9
Kappler, F; Su, B; Szwergold, B S et al. (1995) Identification of galactitol 2-phosphate and galactitol 3-phosphate in the lens of galactose-fed rats. Metabolism 44:1527-31
Lal, S; Szwergold, B S; Kappler, F et al. (1994) Effect of pH on the bioenergetics of perfused porcine lenses. Curr Eye Res 13:239-42
Lal, S; Szwergold, B S; Kappler, F et al. (1993) Detection of fructose-3-phosphokinase activity in intact mammalian lenses by 31P NMR spectroscopy. J Biol Chem 268:7763-7
Petersen, A; Kappler, F; Szwergold, B S et al. (1992) Fructose metabolism in the human erythrocyte. Phosphorylation to fructose 3-phosphate. Biochem J 284 ( Pt 2):363-6

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