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Literature summary for 1.7.1.6 extracted from

  • Imran, M.; Negm, F.; Hussain, S.; Ashraf, M.; Ashraf, M.; Ahmad, Z.; Arshad, M.; Crowley, D.
    Characterization and purification of membrane-bound azoreductase from azo dye degrading Shewanella sp. strain IFN4 (2016), CSAWAC, 44, 1523-1530 .
No PubMed abstract available

Activating Compound

Activating Compound Comment Organism Structure
anthraquinone-2,6-disulfonic acid activates about 2.5fold Shewanella sp. IFN4
anthraquinone-2-sulfonic acid activates about 3fold Shewanella sp. IFN4
additional information the enzyme is stimulated on the addition of flavin or quinone compounds. Supplementation of the azoreductase assay with redox active substances (riboflavin, anthraquinone-2,6-disulfonic acid, and anthraquinone-2-sulfonic acid) increases the specific activity of membrane-bound azoreductase as the shuttling of electrons to azo substrate is promoted Shewanella sp. IFN4
riboflavin activates about 2fold Shewanella sp. IFN4

Localization

Localization Comment Organism GeneOntology No. Textmining
additional information the azoreductase of the Shewanella sp. strain IFN4 reduces the azo dyes extracellularly while being attached with the plasma membrane Shewanella sp. IFN4
-
-
plasma membrane membrane-bound azoreductase Shewanella sp. IFN4 5886
-

Molecular Weight [Da]

Molecular Weight [Da] Molecular Weight Maximum [Da] Comment Organism
33000
-
native PAGE Shewanella sp. IFN4

Organism

Organism UniProt Comment Textmining
Shewanella sp. IFN4
-
-
-

Purification (Commentary)

Purification (Comment) Organism
39.3fold by ammonium sulfate fractionation and anion exchange chromatography Shewanella sp. IFN4

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
3.55
-
pH 8.0, 45°C, crude enzyme, substrate reactive black 5 Shewanella sp. IFN4
139.63
-
pH 8.0, 45°C, purified enzyme, substrate reactive black 5 Shewanella sp. IFN4

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
acid red 88 + NADPH + H+
-
Shewanella sp. IFN4 ? + NADP+
-
?
acid yellow 19 + NADPH + H+ low activity Shewanella sp. IFN4 ? + NADP+
-
?
direct red 81 + NADPH + H+
-
Shewanella sp. IFN4 ? + NADP+
-
?
disperse orange 3 + NADPH + H+
-
Shewanella sp. IFN4 ? + NADP+
-
?
additional information wide substrate specificity of the enzyme. No activity with reactive blue 4 Shewanella sp. IFN4 ?
-
?
reactive black 5 + NADPH + H+ best substrate Shewanella sp. IFN4 ? + NADP+
-
?

Synonyms

Synonyms Comment Organism
azoreductase
-
Shewanella sp. IFN4

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
45
-
-
Shewanella sp. IFN4

Temperature Range [°C]

Temperature Minimum [°C] Temperature Maximum [°C] Comment Organism
4 70 activity range, profile overview, inactive at 80°C Shewanella sp. IFN4

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
4 50 partially purified enzyme, pH 8.0, 30 min, stable at Shewanella sp. IFN4
55
-
partially purified enzyme, pH 8.0, 30 min, 50% of maximal activity remaining Shewanella sp. IFN4
70
-
partially purified enzyme, pH 8.0, 30 min, inactivation Shewanella sp. IFN4

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
8
-
-
Shewanella sp. IFN4

pH Range

pH Minimum pH Maximum Comment Organism
5 9.5 activity range, profile overview Shewanella sp. IFN4

Cofactor

Cofactor Comment Organism Structure
NADPH
-
Shewanella sp. IFN4

General Information

General Information Comment Organism
additional information the azoreductase of the Shewanella sp. strain IFN4 reduces the azo dyes extracellularly while being attached with the plasma membrane. Electrons generated by cellular metabolism must be transported outside the cell in order to reduce substrate. Electrons are transferred from the menaquinone pool in the cytoplasmic membrane to the bacterial cell surface through a series of proteins. Shewanella sp. secretes redox-active flavin compounds able to transfer electrons between the cell surface and substrate in a cyclic fashion, a process termed electron shuttling. In the absence of redox-active flavin compounds transfer of electrons to the substrate is a slow process. Therefore, supplementation of the azoreductase assay with redox active substances (riboflavin, anthraquinone-2,6-disulfonic acid, and anthraquinone-2-sulfonic acid) increases the specific activity of membrane-bound azoreductase as the shuttling of electrons to azo substrate is promoted Shewanella sp. IFN4
physiological function the enzyme is identified as a primary functional membrane-bound azoreductase used by members of the genus Shewanella to degrade azo dyes. Complete degradation of azo dyes by bacteria occurs in two sequential steps. In the first step, reductive cleavage of the azo bond takes place under anaerobic conditions, generating colorless aromatic amines, which are further degraded by aerobic processes. The reduction step is carried out mainly by azoreductase enzymes, which then cleave the azo bond by transferring electrons from reducing equivalents (NADH or NADPH) generated from the metabolism of organic compounds to the dye molecule Shewanella sp. IFN4