Oxygenases cytochrome

Matsunaga, I., T. Sumimoto, M. Ayata, and H. Ogura (2002). Functional modulation of a per-oxygenase cytochrome P450 Novel insight into the mechanisms of peroxygenase and peroxidase enzymes. FEBS Lett. 528, 90-94. 

H steroids, phenobarbital, drugs Benzpyrene, Microsomal oxygenase Cytochrome P450, NADPH-cyt c reductase Cytochrome P448... 

Cytochrome P-450 is frequently the oxygenase which detoxifies xenobiotics, including herbicides. Blocking the metaboHsm of a herbicide increases the activity or delays the inactivation, thus increasing the effectiveness of such herbicides as chlortoluron [15545-48-9] and bentazon [25057-89-0]... 

Scheme 10.6 Byproducts of cytochrome P450 oxygenase catalyzed epoxidation. Top N-alkylation of the porphyrin ring. Bottom group migration to give aldehydes. 

Cytochrome P450 (CYP) Cytochrome P450 isozymes Cytochrome P450 mono-oxygenases Mixed function oxidases... 

Cytochrome P450 (CYP) mono-oxygenases, also called mixed function oxidases, are versatile hemoprotein enzymes that catalyze the cleavage of molecular oxygen to incoiporate one oxygen atom into a substrate molecule and one atom into water [1]. The general stoichiometry of the reaction is as follows (S-H, substrate) ... 

P450 Mono-oxygenase System. Table 1 Overview of the cytochrome P450 superfamily in humans... 

Cytochrome P-450 and other heme-containing oxygenases. J. T. Groves, Adv. Inorg. Biochem., 1979,1,119-145 (109). 

FIG. 21 Schematic diagram of cytochrome P450 mono-oxygenase reaction with substrate RH and product ROH. 

The major mono oxygenases in the endoplasmic reticulum are cytochrome P450s—so named because the enzyme was discovered when it was noted that preparations of microsomes that had been chemically reduced and then exposed to carbon monoxide exhibited a distinct peak at 450 nm. Among reasons that this enzyme is important is the fact that approximately 50% of the drugs humans ingest are metabolized by isoforms of cytochrome P450 these enzymes also act on various carcinogens and pollutants. 

Improving functionality may involve a complex biocatalytic system including more than one biocatalyst, as it is the case in BDM reactions. Additionally to the BDS for instance, another biocatalyst active for BDM [395,406], which consists of a heme oxygenase or a Cytochrome reductase could be used to widen up the functionality. 

Andrae U. Evidence for the involvement of cytochrome P-450-dependent mono-oxygenase(s) in the formation of geno-toxic metabolites from N-hydroxyurea. Biochem Biophys Res Commun 1984 118 409-415. 

Cytochrome P-450. Cytochrome P-450 enzymes consist of a large number of haem-containing mono-oxygenases which catalyze aliphatic and aromatic hydroxylations, epoxidations, as well as other oxidation reactions thus, these enzymes are able to cleave aromatic C-H bonds and also... 

---