Literature summary for 5.3.3.1 extracted from

Thomas, J.L.; Duax, W.L.; Addlagatta, A.; Brandt, S.; Fuller, R.R.; Norris, W.
Structure/function relationships responsible for coenzyme specificity and the isomerase activity of human type 1 3 beta-hydroxysteroid dehydrogenase/isomerase (2003), J. Biol. Chem., 278, 35483-35490.

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Cloned(Commentary)

Cloned (Comment)	Organism
mutant enzymes D36A/K37R, D241N, D257L, D258L and D265N are expressed in a baculovirus/Sf9 cell system	Homo sapiens

Protein Variants

Protein Variants	Comment	Organism
D241N	mutant enzyme nearly has full isomerase activity, substantial decrease in 3beta-hydroxysteroid dehydrogenase activity. Mutant enzyme has a basal isomerase activity in the absence of coenzyme that is 10% of the NADH-stimulated turnover number	Homo sapiens
D257L	complete lack of isomerase activity in absence of coenzyme, substantial decrease in 3beta-hydroxysteroid dehydrogenase activity	Homo sapiens
D258L	complete lack of isomerase activity in absence of coenzyme, substantial decrease in 3beta-hydroxysteroid dehydrogenase activity	Homo sapiens
D265N	complete lack of isomerase activity in absence of coenzyme, substantial decrease in 3beta-hydroxysteroid dehydrogenase activity	Homo sapiens
D36A/K37R	mutation shifts the cofactor preference of both 3-beta-hydroxysteroid dehydrogenase and isomerase from NAD(H) to NADP(H)	Homo sapiens

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.0024	-	5-androstene-3,17-dione	27°C, pH 7.4, wild-type enzyme	Homo sapiens
0.0033	-	5-androstene-3,17-dione	27°C, pH 7.4, mutant enzyme D241N	Homo sapiens
0.0044	-	5-androstene-3,17-dione	27°C, pH 7.4, mutant enzyme D265N	Homo sapiens

Organism

Organism	UniProt	Comment	Textmining
Homo sapiens	-	type I 3beta-hydroxysteroid dehydrogenase/isomerase	-

Purification (Commentary)

Purification (Comment)	Organism
mutant enzymes D36A/K37R, D241N, D257L, D258L and D265N are expressed in a baculovirus/Sf9 cell system	Homo sapiens

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
5-Androstene-3,17-dione	-	Homo sapiens	4-Androstene-3,17-dione	-	?
dehydroepiandrosterone	-	Homo sapiens	3beta-hydroxy-4-androsten-17-one	-	?

Synonyms

Synonyms	Comment	Organism
3beta-HSD/isomerase	-	Homo sapiens
type I 3beta-hydroxysteroid dehydrogenase/isomerase	-	Homo sapiens

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
0.295	-	5-androstene-3,17-dione	27°C, pH 7.4, mutant enzyme D265N	Homo sapiens
0.48	-	5-androstene-3,17-dione	27°C, pH 7.4, mutant enzyme D241N	Homo sapiens
0.557	-	5-androstene-3,17-dione	27°C, pH 7.4, wild-type enzyme	Homo sapiens
6.08	-	5-androstene-3,17-dione	27°C, pH 7.4, wild-type enzyme	Homo sapiens

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
7.5	-	wild-type 1 isomerase and mutant enzymes D241N and D265N	Homo sapiens

pH Range

pH Minimum	pH Maximum	Comment	Organism
6.5	8	pH 6.5: about 55% of maximal activity, wild-type enzyme and mutant enzyme D265N, about 65% of maximal activity, mutant enzyme D241N, about 85% of maximal activity mutant enzyme D257L and D258L. pH 8.0: about 50% of maximal activity, wild-type enzyme and mutant enzymes D241N, 95% of maximal activity, mutant enzyme D258L	Homo sapiens

Cofactor

Cofactor	Comment	Organism	Structure
NADH	wild-type 1 isomerase is activated only by NADH with NADPH producing no isomerase activity. D36A/K37R mutation shifts the cofactor preference of both 3-beta-hydroxysteroid dehydrogenase and isomerase from NAD(H) to NADP(H)	Homo sapiens
NADPH	D36A/K37R mutation shifts the cofactor preference of both 3-beta-hydroxysteroid dehydrogenase and isomerase from NAD(H) to NADP(H)	Homo sapiens

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Release 2023.1 (January 2023)