Mixed function oxygenase activity in the blue crab, Callinectes Sapidus: characterization of enzyme activity from stomach tissue

摘要: Abstract 1. The mixed function oxygenase, arylhydrocarbon hydroxylase (AHH), was characterized from stomach tissue of blue crab. Maximal enzyme activity attained at 30°C and pH 7.5 in the presence NADPH, oxygen, magnesium when benzo(a)pyrene employed as substrate. 2. Components mfo system, cytochrome P-450 phospholipid, were shown necessary for maximal by use inhibitors, detergents, inhibition phospholipase c spectral observations P-420. remaining component, NADPH reductase, assayed using electron recipient. 3. Four other polycylic aromatic compounds modified (phenanthrene, benz(a)anthracene, 7,12-dimethylbenz(a)anthracene, 5,6-chysene) addition to under vitro assay conditions. 4. major products metabolism phenols, 3-hydroxy-benzo(a)pyrene 9-hydroxybenzo(a)pyrene with minor amounts diols, probably trans-4,5-dihydrodiol trans-7,8-dihydrodiol benzo(a)pyrene. 5. Two oxygenase activities, 7-ethoxycoumarin de-ethylase 7-ethoxyresorufin dealkylase, also be present microsomes. 6. No increase AHH occurred after injection benz(a)anthracene or phenobarbital feeding food comtaminated benz(a)anthracene. 7. Inhibition low concentrations 7,8-naphtoflavone (84% 10−6 M) lack induction suggested important differences between crabs animals .