Nitro-reductase

Adamson RH, Dixon RL, Francis EL, Rail DP (1965) Comparative biochemistry of drug metabolism by azo and nitro reductase. Proc Natl Acad Sci USA 54 1386-1391... 

The environmentally benign digestion process (EBDP) uses nitro-reductase enzymes commonly found in spinach, buttermilk, fungi, bacteria, or porcine heart to reduce explosive compounds... 

The excretion of amines is unusual in animals. Amines are highly toxic and one method employed by vertebrates to detoxify them is via monoamine oxidase, an enzyme which has been detected in H. diminuta (569). Amines can arise from the decarboxylation of the appropriate amino acid, e.g. glycine and alanine can give rise to methylamine and ethylamine, respectively. Another possible source of amines may be the reduction of azo or nitro compounds (39) and azo- and nitro-reductase activity has been reported from M. expansa (180, 181). Furthermore, the physiologically active amines octopamine, dopamine, adrenalin and serotonin (5-hydroxytryptamine) have been demonstrated in cestodes (283, 296, 435, 681, 682, 758, 859), where they probably function predominantly as neurotransmitters (see Chapter 2). 

Douch, P. G. C. (1976a). Azo- and nitro-reductases of the cestode Moniezia expansa. Substrate specificity, reaction products and the effects of flavins and other compounds. Xenobiotica, 6 339-404. 

Biorcduction of nitro compounds is carried out by NADPH-dependent microsomal and soluble nitro reductases present in the liver. A multicomponent hepatic microsomal reductase system requiring NADPH appears to be responsible for azo reduction. " " In addition, bacterial reductases present in the intestine can reduce nitro and azo compounds, especially those that are absorbed poorly or excreted mainly in the bile. - ... 

Lipoxygenase Malate dehydrogenase Metallo-endopeptidase N-Methyl transferase Monoamine oxidase Mixed-function oxidase (cytochrome P450 dependent) NADH2 diaphorase NADPH2 diaphorase Neutral endopeptidase 24.11 Nitro oxide synthase Nitro reductase 5 -Nucleotidase Peroxidase... 

Kamrn J J, Gillette JR. 1963. Mechanism of stimulation of mammalian nitro reductase by flavins. Life... 

Saz AK, Slie RB. 1954. The inhibition of organic nitro reductase by aureomycin in cell-free extracts. 

II. Cofactor requirements for the nitro reductase enzyme complex. Arch Biochem Biophys 51 5-16. 

Nitro-radical anions have proved to be especially accessible to ESR study [180-183], The large nitrogen hyperfine splitting in the radical anion often leads to partly or completely resolved hyperfine structure (Fig. 12) that can be analyzed directly or by computer simulation. In the case of the nitro compound furylfuramide (AF-2), the cis-trans isomerization catalyzed by nitro reductases appears to proceed via the radical anion ESR spectra of both cis and trans radical anions have been resolved during reduction of the cis parent compound. 

The ej. can perform yet other reactions such as dechlorination of chlorinated aliphatic hydrocarbons. This can be either oxidative, in which case the products are ketones, or reductive, as with carbon tetrachloride which produces the highly toxic free radical CH2 (Salmon, Jones and Mackrodt, 1981). Moreover, the ej. carry at least two reducing enzymes a nitro-reductase and an azo-reductase, both of which produce primary amines. 

Dixon DR, Jones IM, Harrison FL (1985) Cytogenetic evidence of inducible processes linked with metabolism of a xenobiotic chemical in adult and larval Mytilus edulis. Sci Total Environ 46 1-8 Douch PGC (1976) Azo- and nitro-reductase activities and cytochromes of Ascaris lumbricoides var. suum and Moniezia expansa. Xenobiotica 6 531-536... 

Beta-glucuronidase Aryl acylamidase Monoamine oxidase Diamine oxidase Azobenzene reductase Nitro reductase... 

Aromatic nitro and azo compounds are reduced by hepatic enzymes of mammals, birds, reptiles, fish, and bacteria. Azo-reductase and nitro-reductase are similar in that they have low affinities for their substrates in addition, they are both flavoproteins having FAD as their prosthetic group. Fouxs et al. [57]... 

A. K. Saz and R. B. She, The inhibition of organic nitro reductase by aureomycin in cell-free extracts. II. Cofactor requirements for the nitro reductase enzyme complex. Arch. Biochem. Biophys. 51, 5-16 (1954). 

K. Durchschein, M. Hall, K. Faber, Unusual reactions mediated by FMN-dependent ene- and nitro-reductases, Green Chem. 7 (2013) 1764-1772. 

The rates at which one-electron reduction of nitro compounds proceeds can be correlated linearly to their one-electron midpoint redox potentials as described by Clark et al. (13), for example. Bryant and DeLuca (10) reported on the purification from Enterobacter cloacae of a nitro reductase that was oxygen-insensitive and there-... 

Bryant, C., and M. DeLuca. 1991. Purification and characterization of an oxygen-insensitive NAD(P)H nitro reductase from Enterobacter cloacae. J. Biol. Chem. 266 4119-4125. 

Saz, A. K. and R. B. Slie. 1954. Reversal of aureomycin inhibition of bacterial cell-free nitro reductase by manganese. J. Biol. Chem. 210 407-412. 

Moreover, at least two reducing enzymes are present a nitro-reductase (—NOg - NHg), for which chloramphenicol is a substrate, and an azoreductase. 

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