Literature summary for 1.14.14.17 extracted from

Abe, I.; Abe, T.; Lou, W.; Masuoka, T.; Noguchi, H.
Site-directed mutagenesis of conserved aromatic residues in rat squalene epoxidase (2007), Biochem. Biophys. Res. Commun., 352, 259-263.

Search for more literature for 1.14.14.17

Cloned(Commentary)

Cloned (Comment)	Organism
DNA and amino acid sequence determination and analysis, expression of His-tagged wild-type and mutant enzymes in Escherichia coli strain BL21(DE3)	Rattus norvegicus

Protein Variants

Protein Variants	Comment	Organism
F203A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
F223A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme, the F223A mutant no longer accepts (3S)2,3-oxidosqualene as a substrate	Rattus norvegicus
F228A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
F287A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
F305A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
F375A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
F476A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
F491A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
F522A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
F523A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
Y194A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
Y209A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
Y334A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
Y473A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme, the mutant converts (3S)2,3-oxidosqualene to (3S,22S)2,3-22,23-dioxidosqualene twice more efficiently than wild-type enzyme	Rattus norvegicus
Y493A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus
Y528A	site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme	Rattus norvegicus

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.00425	-	(3S)-squalene-2,3-epoxide	pH 7.4, 37°C, recombinant His-tagged wild-type enzyme	Rattus norvegicus
0.00987	-	squalene	pH 7.4, 37°C, recombinant His-tagged wild-type enzyme	Rattus norvegicus

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
squalene + AH2 + O2	Rattus norvegicus	rate-limiting step in chloesterol biosynthesis	(3S)-squalene-2,3-epoxide + A + H2O	-	?

Organism

Organism	UniProt	Comment	Textmining
Rattus norvegicus	-	-	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant His-tagged wild-type and mutant enzymes from Escherichia coli strain BL21(DE3) by nickel affinity chromatography	Rattus norvegicus

Reaction

Reaction	Comment	Organism	Reaction ID
squalene + [reduced NADPH-hemoprotein reductase] + O2 = (3S)-2,3-epoxy-2,3-dihydrosqualene + [oxidized NADPH-hemoprotein reductase] + H2O	aromatic amino acid residues located at the substrate-binding domain of the active-site, e.g. Ph223 and Tyr473, control the stereochemical course of the enzyme reaction, mechanism of regio- and stereo-specific epoxidation of squalene to (3S)2,3-oxidosqualene, overview	Rattus norvegicus	a

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
(3S)-squalene-2,3-epoxide + AH2 + O2	the wild-type enzyme also catalyzes conversion of (3S)2,3-oxidosqualene to (3S,22S)-2,3-22,23-dioxidosqualene	Rattus norvegicus	(3S,22S)-2,3-22,23-dioxidosqualene + A + H2O	-	?
squalene + AH2 + O2	rate-limiting step in chloesterol biosynthesis	Rattus norvegicus	(3S)-squalene-2,3-epoxide + A + H2O	-	?
squalene + AH2 + O2	aromatic amino acid residues located at the substrate-binding domain of the active-site, e.g. Ph223 and Tyr473, control the stereochemical course of the enzyme reaction, mechanism of regio- and stereo-specific epoxidation of squalene to (3S)2,3-oxidosqualene, overview	Rattus norvegicus	(3S)-squalene-2,3-epoxide + A + H2O	-	?

Synonyms

Synonyms	Comment	Organism
squalene epoxidase	-	Rattus norvegicus

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
37	-	assay at	Rattus norvegicus

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
0.0075	-	(3S)-squalene-2,3-epoxide	pH 7.4, 37°C, recombinant His-tagged wild-type enzyme	Rattus norvegicus
0.076	-	squalene	pH 7.4, 37°C, recombinant His-tagged wild-type enzyme	Rattus norvegicus

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
7.4	-	assay at	Rattus norvegicus

Cofactor

Cofactor	Comment	Organism	Structure
FAD	sequence determination of the FAD-binding site with the dinucleotide-binding GXGXXG motif, and DG and GD motif	Rattus norvegicus

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Release 2023.1 (January 2023)