TABLE 4.

Effects of cytochrome P450 inhibitors on RDX biotransformation activities of rabbit liver cytochrome P450 2B4 and Rhodococcus sp. strain DN22^a

Inhibitor (200 μM)	% Inhibition of activity
	Cytochrome P450 2B4 (100 μg/ml)	Rhodococcus sp. strain DN22 (5 mg [wet wt]/ml)b
Control (no inhibitor)	0	0
Ellipticine	75 ± 4d	76 ± 7
Metyrapone	68 ± 8	60 ± 6
Phenylhydrazine	70 ± 7	77 ± 5
1-Aminobenzotriazole	55 ± 7	43 ± 7
Carbon monoxidec	82 ± 6	48 ± 5

^aThe RDX transformation activity without inhibitor was considered 0% inhibition; the 100% activities for cytochrome P450 2B4 and Rhodococcus sp. strain DN22 were 9.0 nmol min⁻¹ mg of protein⁻¹ and 0.12 nmol min⁻¹ mg of biomass⁻¹, respectively.

^bA washed and centrifuged cell pellet was used as wet biomass.

^cCarbon monoxide was bubbled through the aqueous phase and headspace for 60 s in sealed vials.

^dThe values are means ± standard deviations (n = 3).