Journal article
Aldose reductase catalyzes reduction of the lipid peroxidation product 4-oxonon-2-enal
Chemical research in toxicology, Vol.16(11), pp.1418-1423
11/2003
DOI: 10.1021/tx0300378
PMID: 14615967
Abstract
Recent studies found that 4-oxonon-2-enal (4ONE) is a highly reactive product of lipid peroxidation that can modify peptides and protein sulfhydryls. Because aldose reductase (AR) was shown earlier to catalyze reduction of an alpha,beta-unsaturated lipid aldehyde, 4-hydroxynon-2-enal (4HNE), it was systematically investigated if this enzyme could represent a pathway for 4ONE metabolism as well. 4ONE, the glutathione (GSH) conjugate of 4ONE (GS-4ONE), and 1-hydroxynonen-4-one (1HNO), the predicted initial metabolite of 4ONE reduction, were incubated with AR and NADPH, and kinetic constants were measured. The initial product of AR-mediated 4ONE reduction was identified as 1HNO, which could be further reduced to DHN, catalyzed by AR. This result indicates that the order of 4ONE carbonyl reduction is aldehyde and then ketone. 1HNO was found to be an electrophile toward GSH with reactivity approximately 55-fold less than 4ONE but approximately 2-fold higher than that of 4HNE. The enzyme had activity toward GS-4ONE, exhibiting a approximately 4-fold higher k(cat)/K(M) for GS-4ONE as compared to 4ONE. In the presence of NADPH, 4ONE did not inactivate AR, whereas in the absence of the cofactor, approximately 60% of the enzyme activity was lost. The orientation of 4ONE in the AR active site was predicted using molecular modeling to explain the reactivity of 4ONE toward the enzyme. These simulations revealed that concurrent with NADPH binding to AR, Cys 298 is oriented such that the thiol group will not interact with 4ONE. Results of the present study are the first to demonstrate that AR may represent a pathway for metabolism of 4ONE and GS-4ONE.
Details
- Title: Subtitle
- Aldose reductase catalyzes reduction of the lipid peroxidation product 4-oxonon-2-enal
- Creators
- Jonathan A Doorn - Department of Pharmaceutical Sciences, School of Pharmacy, The University of Colorado Health Sciences Center, Denver, Colorado 80262, USASatish K SrivastavaDennis R Petersen
- Resource Type
- Journal article
- Publication Details
- Chemical research in toxicology, Vol.16(11), pp.1418-1423
- Publisher
- United States
- DOI
- 10.1021/tx0300378
- PMID
- 14615967
- ISSN
- 0893-228X
- eISSN
- 1520-5010
- Grant note
- F32ES 11937 / NIEHS NIH HHS R01ES09410 / NIEHS NIH HHS R01AA09300 / NIAAA NIH HHS DK36118 / NIDDK NIH HHS
- Language
- English
- Date published
- 11/2003
- Academic Unit
- Iowa Neuroscience Institute; Pharmaceutical Sciences and Experimental Therapeutics; Medicinal and Natural Products Chemistry
- Record Identifier
- 9984070863602771
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