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 | 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 Maximum [Da] | Comment | Organism |
---|---|---|---|
33000 | - |
native PAGE | Shewanella sp. IFN4 |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Shewanella sp. IFN4 | - |
- |
- |
Purification (Comment) | Organism |
---|---|
39.3fold by ammonium sulfate fractionation and anion exchange chromatography | Shewanella sp. IFN4 |
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 | 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 | Comment | Organism |
---|---|---|
azoreductase | - |
Shewanella sp. IFN4 |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
45 | - |
- |
Shewanella sp. IFN4 |
Temperature Minimum [°C] | Temperature Maximum [°C] | Comment | Organism |
---|---|---|---|
4 | 70 | activity range, profile overview, inactive at 80°C | Shewanella sp. IFN4 |
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 Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
- |
Shewanella sp. IFN4 |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
5 | 9.5 | activity range, profile overview | Shewanella sp. IFN4 |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NADPH | - |
Shewanella sp. IFN4 |
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 |