In Vivo Glycation of Aldehyde Reductase, a Major 3-deoxyglucosone Reducing Enzyme: Identification of Glycation Sites

Biochemistry. 1995 Jan 31;34(4):1433-8. doi: 10.1021/bi00004a038.

Abstract

We have reported that the enzyme which reduces 3-deoxyglucosone (3-DG), a major intermediate and a potent cross-linker in the Maillard reaction, is identical with aldehyde reductase [Takahashi, M., Fujii, J., Teshima, T., Suzuki, K., Shiba, T., & Taniguchi, N. (1993) Gene 127, 249-253]. The enzyme purified from normal rat liver was found to be partially glycated as judged by binding to a boronate column and reactivity to anti-epsilon-hexitol lysine IgG. Sites of in vivo glycation of rat liver aldehyde reductase were identified by sequencing of digested peptides labeled with NaB[3H]4 and by mass spectrometry. The major glycated sites were lysines 67, 84, and 140. The glycated enzyme had low catalytic efficiency (kcat/Km) as compared to the nonglycated form. In streptozotocin-induced diabetic rats, the glycated form was significantly increased in kidneys. Because the enzyme plays a role in detoxifying 3-DG formed through the Maillard reaction in vivo, glycation of aldehyde reductase and reduction of its activity may result in the metabolic imbalance under diabetic conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehyde Reductase / chemistry*
  • Amino Acid Sequence
  • Animals
  • Deoxyglucose / analogs & derivatives*
  • Deoxyglucose / chemistry
  • Diabetes Mellitus, Experimental / enzymology
  • Glycosylation
  • Kidney / enzymology
  • Liver / enzymology
  • Molecular Sequence Data
  • Oxidation-Reduction
  • Peptide Mapping
  • Protein Processing, Post-Translational
  • Rats

Substances

  • Deoxyglucose
  • Aldehyde Reductase
  • 3-deoxyglucosone