title: Modulation of activity and inhibitor sensitivity of rabbit aldose reductase-like protein (AKR1B19) by oxidized glutathione and SH-reagents.
abstract: Rabbit aldo-keto reductase (AKR) 1B19 is an ortholog of human aldose reductase-like protein (ARLP), AKR1B10, showing 86% amino acid sequence identity. AKR1B19 exhibits the highest catalytic efficiency for 4-oxo-2-nonenal, a major product of lipid peroxidation, compared to known reductases of this aldehyde. In this study, we found that the reductase activity of AKR1B19 was activated to about 5-fold immediately after the addition of 10 μM SH-reagents (p-chloromercuriphenylsulfonic acid and p-chloromercuribenzoic acid) in the absence or presence of NADPH. In addition, a maximum of 3-fold activation of AKR1B19 was induced by incubation with glutathione disulfide (GSSG) for 1h. The activated enzyme was converted into the native enzyme by further incubation with dithiothreitol and glutathione. The activation was abolished by the C299S mutation of AKR1B19, and the glutathionylated Cys299 was identified by mass spectrometry analysis. The Cys299-modified enzyme displayed different kinetic alterations depending on substrates and inhibitors. In the reduction of 4-oxo-2-nonenal, the catalytic efficiency was increased. Thus, AKR1B10 may be modulated by cellular ratio of GSSG/glutathione and more efficiently act as a detoxifying enzyme for the cytotoxic aldehyde under oxidatively stressed conditions. Furthermore, such an activity alteration by GSSG was not detected in AKR1B10 and rat ARLPs, suggesting the presence of a GSSG-binding site near Cys299 in AKR1B19.
authors.affiliation: Gifu Pharmaceutical University, Gifu 501-1196, Japan. sendo@gifu-pu.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Endo
authors.forename: Airi
authors.initials: A
authors.lastname: Fujimoto
authors.forename: Sho
authors.initials: S
authors.lastname: Kumada
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Matsunaga
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ohno
authors.forename: Jun'ichi
authors.initials: J
authors.lastname: Mano
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tajima
authors.forename: Ossama
authors.initials: O
authors.lastname: El-Kabbani
authors.forename: Akira
authors.initials: A
authors.lastname: Hara
mesh_terms: D000429:Alcohol Oxidoreductases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D000447:Aldehydes / Q000378:metabolism / Q000494:pharmacology; D000074408:Aldo-Keto Reductases; D000818:Animals; D002384:Catalysis / Q000187:drug effects; D004229:Dithiothreitol / Q000494:pharmacology; D005978:Glutathione / Q000494:pharmacology; D019803:Glutathione Disulfide / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D009154:Mutation / Q000235:genetics; D009249:NADP / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D011817:Rabbits; D051381:Rats; D013439:Sulfhydryl Reagents / Q000494:pharmacology*
chemical_list: C403894:4-oxo-2-nonenal; D000447:Aldehydes; D013439:Sulfhydryl Reagents; D009249:NADP; D000429:Alcohol Oxidoreductases; C120471:AKR1B10 protein, human; D000074408:Aldo-Keto Reductases; D000449:Aldehyde Reductase; D005978:Glutathione; D004229:Dithiothreitol; D019803:Glutathione Disulfide