ABA 8′-hydroxylase acitivity of the recombinant CYP707A3 microsomes
| Assay conditions | ABA 8′-Hydroxylase Activity PA + 8′-OH-ABAb | Relative Activity |
|---|---|---|
| ng | % | |
| Completea | 197 ± 15 | 100 |
| - NADPH | n.d.c | - |
| - NADPH + 100 μM NADH | n.d. | - |
| + AR1 (NADPH-P450 reductase) | 338 ± 6 | 172 |
| +100 μM cytochrome c | n.d. | - |
| - (+)-ABA + 100 μM (-)-ABA | n.d. | - |
↵a The complete reaction mixture contained 50 mm potassium phosphate (pH 7.25), 50 μg/mL recombinant CYP707A3 microsomes, 100 μm NADPH, and 100 μm (+)-ABA.
↵b Reactions were initiated by addition of NADPH and carried out in the reaction mixture at 30°C for 10 min. The amounts of the reaction products (PA and 8′-OH-ABA) were estimated as the relative response to standard PA. Values are mean ± sd of three separate determinations.
↵c Not detected. The detection limit for the total amounts of PA and 8′-OH-ABA in the reaction mixtures was 50 ng.