Metabolic activation of polycyclic aromatic hydrocarbon trans-dihydrodiols by ubiquitously expressed aldehyde reductase (AKR1A1).
Chem Biol Interact
; 130-132(1-3): 815-24, 2001 Jan 30.
Article
em En
| MEDLINE
| ID: mdl-11306097
ABSTRACT
Polycyclic aromatic hydrocarbons (PAHs) are metabolized to trans-dihydrodiol proximate carcinogens by CYP1A1 and epoxide hydrolase (EH). CYP1A1 or aldo-keto reductases (AKRs) from the 1C subfamily can further activate the trans-dihydrodiols by forming either anti-diol-epoxides or reactive and redox active o-quinones, respectively. To determine whether other AKR superfamily members can divert trans-dihydrodiols to o-quinones, the cDNA encoding human aldehyde reductase (AKR1A1) was isolated from hepatoma HepG2 cells using RT-PCR, subcloned into a prokaryotic expression vector, overexpressed in E. coli and purified to homogeneity in milligram amounts. Studies revealed that AKR1A1 preferentially oxidized the metabolically relevant (-)-[3R,4R]-dihydroxy-3,4-dihydrobenz[a]anthracene. AKR1A1 also displayed high utilization ratios (V(max)/K(m)) for the following PAH trans-dihydrodiols (+/-)trans-3,4-dihydroxy-3,4-dihydro-7-methylbenz[a]anthracene, (+/-)trans-3,4-dihydroxy-3,4-dihydro-7,12-dimethylbenz[a]anthracene and (+/-)trans-7,8-dihydroxy-7,8-dihydro-5-methylchrysene. Multiple tissue expression (MTE) arrays were used to measure the co-expressed of CYP1A1, EH and AKR1A1. All the three enzymes co-expressed to sites of PAH activation. The high catalytic efficiency of AKR1A1 for potent proximate carcinogen trans-dihydrodiols and its presence in tissues that contain CYP1A1 and EH suggests that it plays an important role in this alternative pathway of PAH activation (supported by CA39504).
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hidrocarbonetos Policíclicos Aromáticos
/
Aldeído Redutase
Limite:
Humans
Idioma:
En
Revista:
Chem Biol Interact
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Estados Unidos