Metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, in mouse liver by alcohol dehydrogenase Adh1 and aldehyde reductase AKR1A4
| Autor: | Duncan M. Short, David G. Watson, Elizabeth M. Ellis, Oleg A. Barski, Gail McGarvie, Robert C. Lyon |
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| Rok vydání: | 2006 |
| Předmět: |
Male
Metabolite Mice Inbred Strains In Vitro Techniques Pyrazole Toxicology High-performance liquid chromatography Mice chemistry.chemical_compound Affinity chromatography Aldehyde Reductase Animals Cloning Molecular Alcohol dehydrogenase Pharmacology chemistry.chemical_classification Aldehydes biology Alcohol Dehydrogenase Benzene Stereoisomerism Metabolism Enzyme Liver chemistry Biochemistry Inactivation Metabolic biology.protein |
| Zdroj: | Toxicology and Applied Pharmacology. 210:163-170 |
| ISSN: | 0041-008X |
| DOI: | 10.1016/j.taap.2005.09.017 |
| Popis: | The reductive metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, was studied in mouse liver. Using an HPLC-based stopped assay, the primary reduced metabolite was identified as 6-hydroxy-trans, trans-2,4-hexadienal (OH/CHO) and the secondary metabolite as 1,6-dihydroxy-trans, trans-2,4-hexadiene (OH/OH). The main enzymes responsible for the highest levels of reductase activity towards trans, trans-muconaldehyde were purified from mouse liver soluble fraction first by Q-sepharose chromatography followed by either blue or red dye affinity chromatography. In mouse liver, trans, trans-muconaldehyde is predominantly reduced by an NADH-dependent enzyme, which was identified as alcohol dehydrogenase (Adh1). Kinetic constants obtained for trans, trans-muconaldehyde with the native Adh1 enzyme showed a Vmax of 2141+/-500 nmol/min/mg and a Km of 11+/-4 microM. This enzyme was inhibited by pyrazole with a KI of 3.1+/-0.57 microM. Other fractions were found to contain muconaldehyde reductase activity independent of Adh1, and one enzyme was identified as the NADPH-dependent aldehyde reductase AKR1A4. This showed a Vmax of 115 nmol/min/mg and a Km of 15+/-2 microM and was not inhibited by pyrazole. |
| Databáze: | OpenAIRE |
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