. Author manuscript; available in PMC: 2020 Oct 1.

Published in final edited form as: Mol Cell Endocrinol. 2019 Aug 7;496:110535. doi: 10.1016/j.mce.2019.110535

Table 3.

Kinetic constants of the human SULT2B1b allozymes in catalyzing the sulfation of pregnenolone

Enzyme	Pregnenolone				PAPS

	K_m (μM)	V_max (nmol/min/mg)	K_cat (s⁻¹) ×10⁻³	K_cat/K_m (s⁻¹ M⁻¹)	K_m (μM)
SULT2B1b-wt	8 ± 1	12 ± 0.7	8 ± 0.5	1005 ± 64	1.3 ± 0.2
SULT2B 1b-Pro69Ala	5 ± 1	1 ± 0.0^***	1 ± 0.0^***	206 ± 26^***	3.7 ± 0.5^**
SULT2B1b-Gly72Val	N.D.	N.D.	N.D.	N.D.	N.D.
SULT2B 1b-Thr73Met	13 ± 2^**	3 ± 0.2^***	2 ± 0.1^***	156 ± 16^***	1.0 ± 0.1
SULT2B1b-Arg147His	N.D.	N.D.	N.D.	N.D.	N.D.
SULT2B 1b-Asp 191Asn	6 ± 1	8 ± 0.5^***	6 ± 0.3^***	1013 ± 100	0.7 ± 0.0
SULT2B 1b-Arg230His	7 ± 1	10 ± 0.5^***	7 ± 0.3^**	1010 ± 102	1.3 ± 0.1
SULT2B 1b-Ser244Thr	5 ± 1	5 ± 0.7^***	3 ± 0.5^***	603 ± 21^***	0.6 ± 0.1
SULT2B 1b-Arg274Gln	22 ± 2^***	1 ± 0.1^***	1 ± 0.1^***	45 ± 4^***	23.6 ± 2^***
SULT2B1b-Gly276Val	N.D.	N.D.	N.D.	N.D.	N.D.
SULT2B 1b-Pro345Leu	8 ± 1	10 ± 0.6^***	7 ± 0.5^**	877 ± 27	1.4 ± 0.1

Data shown represent mean ± SD derived from 3 independent experiments.

Statistical significance from SULT2B1b-wt (*p-value<0.05, **p-value<0.001, ***p-value<0.0001) using one-way ANOVA followed by Dunnett’s post hoc analysis.

N.D. no detectable activity.