Table 1

Reconstitution of inactivated P450 with fresh reductase to determine if the inactivation was due to inactivation of reductase or the inactivation of P450 1-a

SystemActivity
Time1-bNADPH
min nmol HFC formed/min/nmol P450
P450:reductase (1:1)
 05.7  ± 0.1
 0+4.8  ± 0.2
405.5  ± 0.4
40+0.6  ± 0.2
Inactivated P450:fresh  reductase (1:4)
* 1-c 7.1  ± 0.2
* 1-c +0.5  ± 0.2
  • 1-a Values represent means ± SD from two sets of triplicate determinations.

  • 1-b Time after addition of NADPH.

  • 1-c After reconstitution of inactivated P450 with fresh reductase, as described in Materials and Methods.