Oxygenases NADH-dependent oxygenase

Figure 22-8 Steps in the demethylation of lanosterol. The most frequent sequence, labeled [1], begins with demethylation at C-14 by the action of a cytochrome P450 and is followed [2] by the successive demethylation of the 0C-CH3 and (S-CH3 at C-4 by an NADH-dependent oxygenase.

In a related approach, nonactivated terminal carbons were directly aminated by using a recombinant whole-cell catalyst [33]. In the key steps, an oxygenase and an m-TA were coupled in vivo within a single Escherichia coU host (BL21) (Scheme 4.8). For the oxidation of the alcohol to the respective aldehyde, the NADH-dependent oxygenase AUcBGT from Pseudomonas putida was used, which allowed the oxyfunctionalization of medium-chain-length alkanes, fatty acids [34], and selected fatty acid methyl esters [35]. Subsequent reductive amination was achieved... 

Naphthalene dioxygenase consists of three components, which form an electron transfer chain an NADH-dependent flavoprotein reductase, a ferredoxin containing two [2Fe2S] Rieske iron-sulfur clusters, and a Rieske oxygenase containing both a [2Fe2S] Rieske iron-sulfiir cluster and a mononuclear iron(II) center in the enzyme active site. ° ... 

The mono-oxygenases which catalyse a series of oxidations such as hydroxylation, epoxidation, heteroatom oxidation and Baeyer-Villiger oxidation (Figure 2.24), depend on NADH or NADPH and cofactors usually Fe or Cu. A particularly important reaction is the direct incorporation of molecular oxygen into non-activated carbon centres, such as in synthesis of important steroidal drags by microbial 11 dr-hydroxylation of... 

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