Enzyme | Control Rate | Rate + Chlorpromazinea | Percentage Increaseb |
---|---|---|---|
nmol/min/mg FMO3 protein | nmol/min/mg FMO3 protein | ||
FMO3 MBP | 5.8 ± 0.2 | 7.2 ± 0.4 | 24.1*** |
Ala360-FMO3 MBP | 6.2 ± 0.1 | 6.7 ± 1.0 | 8.1 |
His360-FMO3 MBP | 7.2 ± 0.2 | 7.3 ± 0.6 | 1.2 |
Gln360-FMO3 MBP | 6.1 ± 0.2 | 6.9 ± 0.4 | 13.2 |
Pro360-FMO3 MBP | 4.6 ± 0.3 | 4.9 ± 0.5 | 5.8 |
↵ a MMI was present at 2 mM and chlorpromazine was present at 1 mM.
↵ b The rate of MMI S-oxygenation in the presence of chlorpromazine was compared with the control rate obtained in the absence of chlorpromazine. Two-way ANOVA was run to determine the effect of FMO3 isoform and modulator on enzyme activity and the interaction of these factors. A Bonferroni post hoc test was performed. *** p < 0.001 vs. value for FMO3 enzyme variant in the absence of chlorpromazine.