Cloned (Comment) | Organism |
---|---|
recombinant expression of His-tagged wild-type and mutant full-length and truncated enzyme variants in Escherichia coli strain JM109 | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
E158K | naturally occuring polymorphism of FMO3, the E158K variant is mostly expressed in African-American and Europeans, the mutant shows reduced activity compared to the wild-type enzyme | Homo sapiens |
E308G | naturally occuring polymorphism of FMO3, the E308G is widely distributed in Asians and Europeans, the mutant shows reduced activity compared to the wild-type enzyme | Homo sapiens |
additional information | generation of truncated forms of wild-type and mutant enzymes, the 17 amino acid truncation at the C-terminal of FMO3 results in a more soluble protein, the truncated enzymes are better catalysts than the full-length proteins. The truncated enzymes are not only fully active, but also have a higher vmax compared to their full-length counterparts, the latter observation might be the result of their higher solubility. The mutations have no major effect on the interaction of the FAD cofactor with the protein | Homo sapiens |
V257M | naturally occuring polymorphism of FMO3, the V257M polymorphic variant is predominantly present in Asians, the mutant shows reduced activity compared to the wild-type enzyme | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | Michaelis-Menten kinetics, potentiometric titrations of the flavin cofactor of FMO3 and the calculated reduction potentials for full-length wild-type and polymorphic variants of FMO3 and that of the truncated form of the wild-type | Homo sapiens | |
0.00134 | - |
tamoxifen | recombinant His-tagged truncated mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.0016 | - |
tamoxifen | recombinant His-tagged full-length mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.0025 | - |
tamoxifen | recombinant His-tagged full-length mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0029 | - |
tamoxifen | recombinant His-tagged truncated mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0056 | - |
tamoxifen | recombinant His-tagged truncated wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.0064 | - |
tamoxifen | recombinant His-tagged full-length wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.0071 | - |
tamoxifen | recombinant His-tagged truncated mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.0081 | - |
tamoxifen | recombinant His-tagged full-length mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.0101 | - |
sulindac sulfide | recombinant His-tagged full-length mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0103 | - |
sulindac sulfide | recombinant His-tagged truncated mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0103 | - |
sulindac sulfide | recombinant His-tagged truncated mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.0127 | - |
sulindac sulfide | recombinant His-tagged truncated wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.0143 | - |
sulindac sulfide | recombinant His-tagged full-length mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.0151 | - |
sulindac sulfide | recombinant His-tagged full-length mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.0156 | - |
sulindac sulfide | recombinant His-tagged full-length wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.0163 | - |
sulindac sulfide | recombinant His-tagged truncated mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.0345 | - |
Benzydamine | recombinant His-tagged full-length mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0373 | - |
Benzydamine | recombinant His-tagged full-length mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.038 | - |
Benzydamine | recombinant His-tagged truncated mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.0397 | - |
Benzydamine | recombinant His-tagged truncated mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.052 | - |
Benzydamine | recombinant His-tagged full-length wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.053 | - |
Benzydamine | recombinant His-tagged truncated wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.0593 | - |
Benzydamine | recombinant His-tagged full-length mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.0659 | - |
Benzydamine | recombinant His-tagged truncated mutant E158K, pH 7.4, 37°C | Homo sapiens |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
membrane | FMO3 is membrane-bound | Homo sapiens | 16020 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
N,N-dimethylaniline + NADPH + H+ + O2 | Homo sapiens | - |
N,N-dimethylaniline N-oxide + NADP+ + H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | P31513 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged wild-type and mutant full-length and truncated enzyme variants from Escherichia coli strain JM109 by anion exchange and nickel affinity chromatography followed by ultrafiltration | Homo sapiens |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
benzydamine + NADPH + H+ + O2 | high activity | Homo sapiens | benzydamine N-oxide + NADP+ + H2O | - |
? | |
additional information | N- and S-oxygenation activity of truncated wild-type human flavin-containing monooxygenase 3 and its common polymorphic variants, overview. The enzyme binds noncovalently one molecule of FAD and is reduced by NADPH before exerting its catalysis | Homo sapiens | ? | - |
- |
|
N,N-dimethylaniline + NADPH + H+ + O2 | - |
Homo sapiens | N,N-dimethylaniline N-oxide + NADP+ + H2O | - |
? | |
sulindac sulfide + NADPH + H+ + O2 | - |
Homo sapiens | sulindac sulfide S-oxide + NADP+ + H2O | - |
? | |
tamoxifen + NADPH + H+ + O2 | - |
Homo sapiens | tamoxifen N-oxide + NADP+ + H2O | - |
? |
Synonyms | Comment | Organism |
---|---|---|
flavin-containing monooxygenase 3 | - |
Homo sapiens |
FMO3 | - |
Homo sapiens |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Homo sapiens |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.003 | - |
Benzydamine | recombinant His-tagged full-length mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0042 | - |
sulindac sulfide | recombinant His-tagged full-length mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.0062 | - |
tamoxifen | recombinant His-tagged full-length mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0062 | - |
sulindac sulfide | recombinant His-tagged full-length mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0068 | - |
sulindac sulfide | recombinant His-tagged full-length mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.0075 | - |
tamoxifen | recombinant His-tagged full-length mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.008 | - |
Benzydamine | recombinant His-tagged truncated mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0093 | - |
sulindac sulfide | recombinant His-tagged full-length wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.0098 | - |
tamoxifen | recombinant His-tagged full-length mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.01 | - |
tamoxifen | recombinant His-tagged truncated mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.0113 | - |
tamoxifen | recombinant His-tagged truncated mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.0115 | - |
sulindac sulfide | recombinant His-tagged truncated mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.0142 | - |
tamoxifen | recombinant His-tagged truncated mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.0148 | - |
sulindac sulfide | recombinant His-tagged truncated mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.018 | - |
Benzydamine | recombinant His-tagged full-length mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.0183 | - |
sulindac sulfide | recombinant His-tagged truncated mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.0188 | - |
tamoxifen | recombinant His-tagged full-length wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.027 | - |
sulindac sulfide | recombinant His-tagged truncated wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.0272 | - |
tamoxifen | recombinant His-tagged truncated wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.029 | - |
Benzydamine | recombinant His-tagged truncated mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.051 | - |
Benzydamine | recombinant His-tagged full-length mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.052 | - |
Benzydamine | recombinant His-tagged full-length wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.058 | - |
Benzydamine | recombinant His-tagged truncated mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.075 | - |
Benzydamine | recombinant His-tagged truncated wild-type enzyme, pH 7.4, 37°C | Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.4 | - |
assay at | Homo sapiens |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | - |
Homo sapiens | |
additional information | the enzyme binds noncovalently one molecule of FAD and is reduced by NADPH before exerting its catalysis | Homo sapiens | |
NADPH | - |
Homo sapiens |
General Information | Comment | Organism |
---|---|---|
malfunction | naturally occurring polymorphic enzyme variants demonstrate differences in rates of turnover of its substrates: xenobiotics including drugs as well as dietary compound | Homo sapiens |
additional information | enzyme protein structure homology-modelling using the PDB ID 6SE3 structure as the template | Homo sapiens |
physiological function | human flavin-containing monooxygenase 3 (FMO3) is a highly polymorphic membrane-bound, phase I drug metabolizing enzyme. Human FMO3 catalyzes the monooxygenation of nucleophilic heteroatom containing chemicals (drugs, pesticides, and xenobiotics) through an unusual mechanism of activation of molecular oxygen via a stable FAD intermediate in the absence of the bound substrate. This mechanism accounts for the broad substrate range as well as uncoupling of this enzyme, i.e. the wastage of electrons without oxygenation of the substrate leading to the formation of reactive oxygen species (ROS) such as the superoxide radical and hydrogen peroxide. FMO3 is the primary catalyst of benzydamine N-oxygenation with minimal contribution from cytochrome P450 enzymes and that N-oxygenation is the major pathway of benzydamine biotransformation in various species in vitro. FMO3 catalyzes the formation of tamoxifen N-oxide. Tamoxifen N-oxide represents a detoxification pathway, after the metabolic activation carried out by cytochrome P450 (tamoxifen alpha-hydroxylation) that leads to products capable of DNA adduction, with potentially significant toxicological consequences. Administered orally, sulindac is a prodrug which is reduced by the gut flora to the active sulfide form before absorption. In vivo, the sulfide form is re-oxidized to sulindac, the latter compound is relatively inactive compared to the sulfide form: this oxidation step leading from sulindac sulfide to sulindac is carried out by FMO3 | Homo sapiens |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.044 | - |
Benzydamine | recombinant His-tagged truncated mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.087 | - |
Benzydamine | recombinant His-tagged full-length mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.202 | - |
Benzydamine | recombinant His-tagged truncated mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.278 | - |
sulindac sulfide | recombinant His-tagged full-length mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.304 | - |
Benzydamine | recombinant His-tagged full-length mutant E158K, pH 7.4, 37°C | Homo sapiens | |
0.476 | - |
sulindac sulfide | recombinant His-tagged full-length mutant V257M, pH 7.4, 37°C | Homo sapiens | |
0.596 | - |
sulindac sulfide | recombinant His-tagged full-length wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
0.614 | - |
sulindac sulfide | recombinant His-tagged full-length mutant E308G, pH 7.4, 37°C | Homo sapiens | |
0.706 | - |
sulindac sulfide | recombinant His-tagged truncated mutant E158K, pH 7.4, 37°C | Homo sapiens | |
1 | - |
Benzydamine | recombinant His-tagged full-length wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
1.21 | - |
tamoxifen | recombinant His-tagged full-length mutant V257M, pH 7.4, 37°C | Homo sapiens | |
1.37 | - |
Benzydamine | recombinant His-tagged full-length mutant V257M, pH 7.4, 37°C | Homo sapiens | |
1.415 | - |
Benzydamine | recombinant His-tagged truncated wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
1.437 | - |
sulindac sulfide | recombinant His-tagged truncated mutant E308G, pH 7.4, 37°C | Homo sapiens | |
1.526 | - |
Benzydamine | recombinant His-tagged truncated mutant V257M, pH 7.4, 37°C | Homo sapiens | |
1.777 | - |
sulindac sulfide | recombinant His-tagged truncated mutant V257M, pH 7.4, 37°C | Homo sapiens | |
2 | - |
tamoxifen | recombinant His-tagged truncated mutant V257M, pH 7.4, 37°C | Homo sapiens | |
2.13 | - |
sulindac sulfide | recombinant His-tagged truncated wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
2.48 | - |
tamoxifen | recombinant His-tagged full-length mutant E308G, pH 7.4, 37°C | Homo sapiens | |
2.94 | - |
tamoxifen | recombinant His-tagged full-length wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
3.45 | - |
tamoxifen | recombinant His-tagged truncated mutant E308G, pH 7.4, 37°C | Homo sapiens | |
4.69 | - |
tamoxifen | recombinant His-tagged full-length mutant E158K, pH 7.4, 37°C | Homo sapiens | |
4.86 | - |
tamoxifen | recombinant His-tagged truncated wild-type enzyme, pH 7.4, 37°C | Homo sapiens | |
8.43 | - |
tamoxifen | recombinant His-tagged truncated mutant E158K, pH 7.4, 37°C | Homo sapiens |