Morphine dehydrogenase

Scheme 2.5c) [24,25], an activity that has potential in opiate biosynthesis. This strain has a morphine dehydrogenase that concomitantly reduces morphine into mor-phinone and has thus found applications in morphine detection. Finally, OYEs that reduce Baylis-Hillman adducts with complementary enantioselectivities have been either identified or generated by protein engineering (Scheme 2.5d) [26]. 

One of the first examples of concurrent oxidation and reduction reactions in a three-enzyme system was reported in 1996 for the biotransformation of morphine to hydromorphone (Scheme 11.2) [6]. Specifically, the NADPH-dependent morphine-6-dehydrogenase (MDH) was coupled to the NADH-dependent morphinone reductase (MR) through the action of a cofactor aspecific (accepting both NADH and NADPH) glutamate dehydrogenase. The latter cofactor regeneration reaction not only allows the use of catalytic amounts of the cofactor but also avoids the accumulation of the reduced cofactor (NADPH) produced by morphine dehydrogenase and the consequent further reduction of hydromorphone to... 

Ziegler, J. Voegtlander, S., Schmidt, J., Kramell, R., Miersch, O., Ammer, C., Gesell, A. and Kutchan, T.M. (2006) Comparative transcript and alkaloid profiling in Papaver species identifies a short chain dehydrogenase/reductase involved in morphine biosynthesis. Plant.., 48,177-92. 

Therapeutic doses of morphine can alter the blood activities of amylase, lipase, lactate dehydrogenase, creatine phosphokinase, and leucine aminopeptidase, BSP retention, and urine glucose concentration (Benedict s) (57-59). 

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