TABLE 3.

Kinetic Analysis of Individual Human SULTs Against Tolvaptan^a

SULT	Kmb μM	Vmax pmol.min−1. cell lysate protein mg−1	Vmax/Km μl.min−1.mg−1
1B1	87.0 ± 15.3	10.9 ± 0.6	0.1 ± 0.02
1C3	4.1 ± 0.4	19.0 ± 0.2	4.6 ± 0.4
1E1	149 ± 24.8	3.5 ± 0.3	0.02 ± 0.004
2A1	56.8 ± 5.8	16.3 ± 0.4	0.3 ± 0.03
2B1	73.7 ± 17.0	3.0 ± 0.2	0.04 ± 0.01

^aAll the reactions were performed using cell lysates for individually overexpressed SULT isoenzyme, and incubations were at 37°C for 1 h, as described in Materials and Methods. Kinetic parameters are reported as mean ± SD for 3 individual experiments.

^bK_m, apparent K_m.

^cV_max values are adjusted per mg of the corresponding cell lysate proteins of individual SULT overexpressing cell line.