Reversibility of catalytic changes in rSULT1A1 after oxidative modification of the enzyme
Pretreatment of rSULT1A1a | |||||
|---|---|---|---|---|---|
| 5 mM DTT | 1 mM GSSG | DTT after GSSGb | |||
| 2-Naphthol, 250 μM | 38.3 ± 4.7 | 50.2 ± 2.1c | 37.4 ± 1.5 | ||
| 4′-OH PCB 6, 100 μM | 0 | 37.3 ± 4.0 | 0 | ||
↵ a 5 mM DTT and/or 1 mM GSSG was incubated with the enzyme at 25°C for 1 h before use in an assay for sulfotransferase activity. Data are the means and S.D. of three determinations.
↵ b One aliquot of GSSG-treated enzyme was further treated with DTT at 25°C for 1 h.
↵ c This value is statistically different from that for the group treated with 5 mM DTT alone (p < 0.05 by t test).