Mouse liver microsomal hexose-6-phosphate dehydrogenase. NADPH generation and utilization in monooxygenation reactions.
Hexose-6-phosphate dehydrogenase (H6PD) activity in washed hepatic microsomes from male ICR mice, when assayed with NADP+ and deoxyglucose-6-phosphate, was partially latent. Brief sonication or detergents activated H6PD causing an approximately 4- and 8.5-fold increase in NADPH generation respectively. The sonicated microsomes exhibited H6PD-linked N-demethylase activity toward aminopyrine. This activity was best sustained in the presence of deoxyglucose-6-phosphate, while galactose-6-phosphate, glucose-6-phosphate, and glucose were less effective. Reaction media containing sonicated microsomes, NADP+ and deoxyglucose-6-phosphate also catalyzed N-demethylation of p-chloro-N-methylaniline, N,N-dimethylaniline and nicotine, O-demethylation of p-nitroanisole, p-hydroxylation of aniline, ring hydroxylation of biphenyl at the 2- and 4-positions, dearylation of parathion, and the N-oxidation of N,N-dimethylaniline. In general, the hexose-6-phosphate dehydrogenase-linked monooxygenation rates were 60% or more of those observed in the presence of exogenous NADPH.
D000633:Aminopyrine N-Demethylase / Q000032:analysis; D000818:Animals; D002237:Carbohydrate Dehydrogenases / Q000032:analysis*; D003640:Dealkylation; D003902:Detergents / Q000494:pharmacology; D004789:Enzyme Activation; D006900:Hydroxylation; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008862:Microsomes, Liver / Q000201:enzymology* / Q000378:metabolism; D009249:NADP / Q000378:metabolism*; D010105:Oxygenases / Q000032:analysis
D003902:Detergents; D009249:NADP; D002237:Carbohydrate Dehydrogenases; C020552:galactose-6-phosphate dehydrogenase; D010105:Oxygenases; D000633:Aminopyrine N-Demethylase