Literature summary for 1.14.13.8 extracted from

Kim, J.; Lee, H.; Roh, Y.J.; Kim, H.U.; Shin, D.; Kim, S.; Son, J.; Lee, A.; Kim, M.; Park, J.; Hwang, S.Y.; Kim, K.; Lee, Y.K.; Jung, H.S.; Hwang, K.Y.; Lee, B.C.
Structural and kinetic insights into flavin-containing monooxygenase and calponin-homology domains in human MICAL3 (2020), IUCrJ, 7, 90-99 .

Search for more literature for 1.14.13.8

Cloned(Commentary)

Cloned (Comment)	Organism
gene FMO3, recombinant expression of His-tagged wild-type and mutant enzymes in Escherichia coli strain JM109	Homo sapiens

Protein Variants

Protein Variants	Comment	Organism
E158K	naturally occuring polymorphic variant and site-directed mutagenesis, the melting temperature and activation energy of the mutant is nearly unaltered compared to the wild-type enzyme	Homo sapiens
E308G	naturally occuring polymorphic variant and site-directed mutagenesis, the mutant is unable to bind the NADP+ cofactor, it shows a significantly higher energy of unfolding (Ea) compared to wild-type	Homo sapiens
additional information	unfolding process of a phase I drug metabolizing enzyme, human flavin-containing monooxygenase 3 (hFMO3) and its single nucleotide polymorphic variants (SNPs) V257M, E158K and E308G are analyzed by differential scanning calorimetry (DSC) indicating that the thermal denaturation of the enzyme is irreversible. The melting temperature (Tm) for the wild-type enzyme and its polymorphic variants is in a range from 46°C to 50°C. Also the activation energies of unfolding (Ea) show no significant differences among all proteins investigated (290-328 KJ/mol), except for the E308G variant that shows a significantly higher Ea of 412 KJ/mol. The presence of the bound NADP+ cofactor stabilizes all the variants by shifting the main Tm by 4-5°C for all the proteins, exception made for E308G where no changes are observed	Homo sapiens
V257M	naturally occuring polymorphic variant and site-directed mutagenesis, the melting temperature and activation energy of the mutant is nearly unaltered compared to the wild-type enzyme	Homo sapiens

Natural Substrates/ Products (Substrates)

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

Organism	UniProt	Comment	Textmining
Homo sapiens	P31513	-	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant His-tagged wild-type and mutant enzymes from Escherichia coli strain JM109 by nickel affinity chromatography and ultrafiltration	Homo sapiens

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
N,N-dimethylaniline + NADPH + H+ + O2	-	Homo sapiens	N,N-dimethylaniline N-oxide + NADP+ + H2O	-	?

Subunits

Subunits	Comment	Organism
More	heat-induced changes in the secondary structure in the presence and absence of NADP+, overview	Homo sapiens

Synonyms

Synonyms	Comment	Organism
flavin-containing monooxygenase	-	Homo sapiens
flavin-containing monooxygenase 3	-	Homo sapiens
hFMO3	-	Homo sapiens

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
25	-	assay at	Homo sapiens

Temperature Stability [°C]

Temperature Stability Minimum [°C]	Temperature Stability Maximum [°C]	Comment	Organism
46	50	differential scanning calorimetry (DSC) indicates that the thermal denaturation of the enzyme is irreversible in all cases. The melting temperature (Tm) for the wild-type enzyme and its polymorphic variants is in a range from 46°C to 50°C at pH 7.4. Calculation for the activation energy of unfolding is performed using a mathematical model, secondary structures of wild-type and mutant enzymes during heat inactivation, overview	Homo sapiens

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
7.4	-	assay at	Homo sapiens

Cofactor

Cofactor	Comment	Organism	Structure
FAD	-	Homo sapiens
NADPH	hFMO3 is reduced by its physiological electron donor NADPH. During the enzyme catalytic cycle, NADPH is consumed, then the reduced enzyme binds molecular oxygen to form a C4ahydroperoxy intermediate of the flavin responsible for the oxygenation of the substrate with the concomitant release of a water molecule. During these steps NADP+ remains bound in the active site leaving only when the catalytic cycle is completed. Heat-induced changes in the secondary structure in the presence and absence of NADP+, overview	Homo sapiens

General Information

General Information	Comment	Organism
malfunction	the hFMO3 gene contains many naturally occuring single SNPs and these mutations can severely affect the activity of the enzyme resulting in lower or abolished activity	Homo sapiens
additional information	heat-induced changes in the secondary structure in the presence and absence of NADP+, overview	Homo sapiens
physiological function	human flavin-containing monooxygenases (hFMOs) comprise a family of five isoenzymes and are the second most important phase 1 drug-metabolizing enzymes after cytochromes P450. Its isoform 3 (hFMO3) is predominantly expressed in the liver where substrates containing nitrogen-, sulphur- and phosphorous-containing soft nucleophiles are transformed into more polar and excretable metabolites. Wild-type hFMO3 contributes to the metabolism of several important drugs such as ranitidine, cimetidine, tamoxifen, clozapine, benzydamine	Homo sapiens

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Release 2023.1 (January 2023)