N-oxidase

P450 IIIA4 Human nf Pregnenolone, 16a-carbonitrile Ethinylestradiol Nifedipine N-oxidase... 

The flavin-dependent mixed-function oxidases include amine N-oxidases and a variety of S-oxidases. They provide an alternative to cytochrome P450-dependent enzymes in the metabolism of xenobiotics. 

The hepatic enzymes responsible for carrying out a-car-bnn hydroxylation reactions arc the cytochrome P-4S0 mixed-function oxidases. The N-hydroxylation or N-oxida-tion reactions, however, appear to be catalyzed not only by cylochrome P-4S0 but also by a second class of hepatic mixed-function oxidases called timine oxidases (sometimes called N oxidases) These enzymes are NADPH-dependent flavoproteins and do not contain cytochrome P450." They require NADPH and molecular oxygen 10 cany out N-oxidation. 

Fig. 6.16 The calicheamicin biosynthetic pathway. The scheme shows the Cal02-catalyzed hydroxylation (shown by an arrow) of the iodinated orsellinic acid moiety, with R predicted to be an ACP or CoA thioester [230], CalElO is a regio-specific NDP-amino sugar N-oxidase involved in the production of the 4-hydroxyamino-...

Johnson HD, Thorson JS (2(X)8) Characterization of CalElO, the N-oxidase involved in ealieheami-cin hydroxyaminosugar formation. J Am Chem Soc 130 17662-17663... 

The reactivity of the individual O—P insecticides is determined by the magnitude of the electrophilic character of the phosphoms atom, the strength of the bond P—X, and the steric effects of the substituents. The electrophilic nature of the central P atom is determined by the relative positions of the shared electron pairs, between atoms bonded to phosphoms, and is a function of the relative electronegativities of the two atoms in each bond (P, 2.1 O, 3.5 S, 2.5 N, 3.0 and C, 2.5). Therefore, it is clear that in phosphate esters (P=0) the phosphoms is much more electrophilic and these are more reactive than phosphorothioate esters (P=S). The latter generally are so stable as to be relatively unreactive with AChE. They owe their biological activity to m vivo oxidation by a microsomal oxidase, a reaction that takes place in insect gut and fat body tissues and in the mammalian Hver. A typical example is the oxidation of parathion (61) to paraoxon [311-45-5] (110). 

Pargyline hydrochloride (Eutonyl, (V-methyl-n-propargylbenzylamine hydrochloride) [306-07-0] M 195.7, m 154-155 , 155 , pK 6.9. Recrystd from EtOH-Et20 and dried in vacuo. It is very soluble in H2O, in which it is unstable. The free base has b 101-103°/ 1mm. It is a glucuronyl transferase inducer and a monoamine oxidase inhibitor, [von Braun et al. Justus Liebigs Ann Chem 445 205 1928, Yeh and Mitchell Experientia 28 298 1972 Langslrom et al. Science 225 1480 1984.]... 

Youdim MBH, Finberg JPM, Tipton KF (1988) Monoamine oxidases. In Trendelenburg U and Weiner N (eds) Catecholamines. II Handbook of experimental pharmacology. Springer Verlag, Berlin, pp 121-197... 

A number of complexes of copper with 1,1-dithiolenes are known they are interesting, inasmuch as they form (1) polynuclear species, e.g., [Cu4(i-mnt)3]2 . Recently, a copper(III) complex of 1,1-dicarboeth-oxy-2-ethylenedithiolate (DED ) was prepared (375) by oxidation of aqueous solutions of K2[Cu(DED)2] with a 10-15% excess of Cu(II) or H202, and of (BzPh3P)2[Cu(DED)2] with I2. The possibility of this system as a model for the Cu "/Cu. system in n-galactose oxidase has been pointed out. Lewis and Miller (113) also prepared M[Cu(S2C CHN02)2] (M = Cu, or Zn) and Cu[Cu S2C C(CN)2 2], and found that they are effective insecticides. 

Monoamine oxidase (MAO-N) from Aspergillus niger and mutants [25]... 

Upon mutagenesis of the monoamine oxidase from Aspergillus niger (MAO-N) within several rounds of directed evolution [65], variant biocatalysts were identified with largely expanded substrate acceptance, enabling also the deracemization of tertiary amines incorporating straight-chain and cyclic structural motifs [66]. 

The aldehyde oxidoreductase from Desulfovibrio gigas shows 52% sequence identity with xanthine oxidase (199, 212) and is, so far, the single representative of the xanthine oxidase family. The 3D structure of MOP was analyzed at 1.8 A resolution in several states oxidized, reduced, desulfo and sulfo forms, and alcohol-bound (200), which has allowed more precise definition of the metal coordination site and contributed to the understanding of its role in catalysis. The overall structure, composed of a single polypeptide of 907 amino acid residues, is organized into four domains two N-terminus smaller domains, which bind the two types of [2Fe-2S] centers and two much larger domains, which harbor the molybdopterin cofactor, deeply buried in the molecule (Fig. 10). The pterin cofactor is present as a cytosine dinucleotide (MCD) and is 15 A away from the molecular surface,... 

Binda C, Li M, Hubalek E, Restelli N, Edmondson DE, Mattevi A. Insights into the mode of inhibition of human mitochondrial monoamine oxidase B from high-resolution crystal structures. Proc Natl Acad Sci USA 2003 100 9750-5. 

Zakharova, N.S. and Petrova, T.A., Investigation of betalains and betalain oxidase of leaf beet, Appl. Biochem. Microbiol., 33, 539, 1997. 

Doukyu N, R Aono (1998) Purification of extracellular cholesterol oxidase with high activity in the presence of organic solvents from Pseudomonas sp. strain ST-200. Appl Environ Microbiol 64 1929-1932. 

Stephan I, B Tshisuaka, S Fetzer, F Lingens (1996) Quinaldine 4-oxidase from Arthrobacter sp. Ru61a, a versatile procaryotic molybdenum-containing hydroxylase active towards N-containing heterocyclic compounds and aromatic aldehydes. Eur J Biochem 236 155-162. 

Whittaker MM, PJ Kersten, N Nakamura, J Sanders-Loehr, ES Schweizer, JW Whittaker (1996) Glyoxal oxidase from Phanerochaete chrysosporium is a new radical copper oxidase. J Biol Chem 271 681-687. 

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