Monoxygenase

Tyrosine hydroxylase (TH) is an enzyme that catalyzes the hydroxylation of tyrosine to 3,4-dihydroxypheny-lalanine in the brain and adrenal glands. TH is the rate-limiting enzyme in the biosynthesis of dopamine. This non-heme iron-dependent monoxygenase requires the presence of the cofactor tetrahydrobiopterin to maintain the metal in its ferrous state. 

Curty, C., Engel, N., and Gossauer, A., Evidence for a monoxygenase-catalyzed primary process in the catabolism of chlorophyll, FEES Lett, 364, 41, 1995. 

The development and reports of methods for colorless chlorophyll derivative (RCCs, FCCs, and NCCs) analysis are relatively recent and the structures of the compounds are being elucidated by deduction from their chromatographic behaviors, spectral characteristics (UV-Vis absorbance spectra), mass spectrometry, and nuclear magnetic resonance analysis. The main obstacle is that these compounds do not accumulate in appreciable quantities in situ and, moreover, there are no standards for them. The determination of the enzymatic activities of red chlorophyll catabolite reductase (RCCR) and pheophorbide a monoxygenase (PAO) also helps to monitor the appearance of colorless derivatives since they are the key enzymes responsible for the loss of green color. ... 

O Keefe DP, PA Harder (1991) Occnrrence and biological function of cytochrome P-450 monoxygenase in the actinomycetes. Mol Microbiol 5 2099-2105. 

Kadiyala V, JC Spain (1998) A two-component monoxygenase catalyzes both the hydroxylation of p-nitrophe-nol and the oxidative release of nitrite from 4-nitrocatechol in Bacillus sphaericus JS905. Appl Environ Microbiol 64 2479-2484. 

The transformation of A-nitrosodimethylamine by Pseudomonas mendocina KRl that has tolu-ene-4-monoxygenase activity was initiated by monooxygenation to the A-nitro compound, which produced A-nitromethylamine and formaldehyde, presumably by hydroxylation of the methyl group (Fournier et al. 2006). 

Tetraethyl and tetramethyl lead under oxidative dealkylation metabolize to the highly neurotoxic metabolites, triethyl and trimethyl lead, respectively. In the liver, the reaction is catalyzed by a cytochrome P-450 dependent monoxygenase system (Kimmel et al. 1977). Complete oxidation of alkyl lead to inorganic lead also occurs (Bolanowska 1968). 

Kimmel EC, Fish RH, Casida JE. 1977. Bioorganotin chemistry Metabolism of organotin compounds in microsomal monoxygenase systems and in mammals J Agric food Chem 25 1-9. 

Dioxygen reduction (oxidase activity) and activation for incorporation into organic substrates are catalysed by a number of mononuclear non-haem iron enzymes. We will first consider the intramolecular dioxygenases, in which both atoms of oxygen are introduced into the substrate, then the monoxygenases (in which we choose to include the pterin-dependent hydroxylases), the large family of a-hetoacid-dependent enzymes, and finally isopenicillin N-synthase. 

Glucosinolate biosynthesis further characterization of the aldoxime-forming microsomal monoxygenases in oilseed rape leaves, Plant Physiol., 1995, 109, 299-305. 

ZHAO, Y., CHRISTENSEN, S.K, FANKHAUSER, C., CASHMAN, J.R., COHEN, J.D., WEIGEL, D., CHORY, J., A role for flavin monoxygenase-like enzymes in auxin biosynthesis, Science, 2001, 291, 306-309. 

Pinto, A., Abraham, N. G., Mullane, K. M., Cytochrome P450-dependent monoxygenase activity and endothelial-dependent relaxations induced by arachidonic acid. J. Pharmucol. Exp. Ther. 236 (1986),... 

Dahlstrom-King L, Couture J, Plaa GL. 1992. Influence of agents affecting monoxygenase activity on taurolithocholic acid-induced cholestasis. Toxicol Lett 63 243-252. 

Peptidylglycine a-hydroxy-lating monoxygenase, WT and Y318E mutant H-atom transfer to Cu-O from benzoyl-glycine... 

Evans, J.P., Ahn, K. and Klinman, J.P. (2003). Evidence that dioxygen and substrate activation are tightly coupled in dopamine (3-monoxygenase. J. Biol. Chem. 278, 49691-49698... 

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