FAD monooxygenases

Zaragoza, A., D. Andres, D. Sarrion, and M. Cascales. 2000. Potentiation of thioaceta-mide hepatotoxicity by phenobarbital in rats. In-ductibility of FAD monooxygenase system and ageeffect. Chem. Biol. Interact. 124(2) 87-101. 

Squalene monooxygenase, an enzyme bound to the endoplasmic reticulum, converts squalene to squalene-2,3-epoxide (Figure 25.35). This reaction employs FAD and NADPH as coenzymes and requires Og as well as a cytosolic protein called soluble protein activator. A second ER membrane enzyme, 2,3-oxidosqualene lanosterol cyclase, catalyzes the second reaction, which involves a succession of 1,2 shifts of hydride ions and methyl groups. 

The hrst enzyme in the degradation of 2-hydroxybiphenyl by Pseudomonas azelaica strain HBPl is an FAD-dependent monooxygenase that produces 2,3-dihydroxybiphenyl (Suske et al. 1999). 

The degradation of phenol is initiated by hydroxylation using a single-component NAD(P)H-depen-dent monooxygenase encoded by pheA (Nurk et al. 1991). In Bacillus thermoglucosidasius, however, the hydroxylase is a two-component system encoded by pheAl and pheA2, and hydroxylation requires supplementation by the second component with FAD(NADH) (Kirchner et al. 2003). 

Stereoselective oxygen transfer to the sulphur atom of alkyl aryl sulphides catalyzed by 2-flavoenzyme monooxygenases afforded optically active sulphoxides in high optical yields . For instance, with ethyl p-tolyl sulphide as substrate cyclohexanone monooxygenase from Actinetobacter produces predominantly (— )-(S)-sulphoxide with 64% e.e. In contrast, FAD-containing dimethylaniline monooxygenase purified from hog liver microsomes affords (+ )-(i )-enantiomer of this sulphoxide with 90% optical purity . ... 

Sabourin, PJ. and Hodgson, E. (1984) Characterization of the purified microsomal FAD-containing monooxygenase from mouse and pig liver. Chemico-Biological Interactions, 51, 125—139. 

The FAD-containing monooxygenase catalyzes oxidation of nucleophilic nitrogen and sulfur atoms in a diverse array of organic compounds. The enzyme... 

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