Skip to main content
. Author manuscript; available in PMC: 2007 Sep 24.
Published in final edited form as: Biochemistry. 2005 Feb 22;44(7):2632–2641. doi: 10.1021/bi0477900

Figure 1. Effect of CYP2B4 and CYP1A2 mediated PROD metabolism as a function of monovalent ion concentration.

Figure 1

CYP2B4, CYP1A2 and reductase were reconstituted in binary (one P450 and reductase) and ternary (mixed P450s and reductase) reconstituted systems. The first and second bars in each group represent binary CYP1A2 and CYP2B4 reconstituted activities, respectively. The third bar represents the results from the mixed reconstituted system, and the fourth bar represents the sum of the rates of the binary systems (sum of the first and second bars). PROD activity was measured under subsaturating conditions (0.5:1.0 reductase:P450). Each binary reconstituted system contained 0.05 μM P450 (CYP1A2 or CYP2B4 alone), 0.025 μM reductase (CPR), and 8.0 μM DLPC. The mixed reconstituted system contained 0.05 μM of both CYP1A2 and CYP2B4, and 0.05 μM CPR. Groups represent the mean ± SEM for three determinations. Significant differences in activities between the sum of the two binary systems compared to the mixed reconstituted system are indicated (*, p < 0.05; **, p < 0.01; ***, p < 0.001). (a) Effect of varying sodium phosphate on PROD activity in simple and mixed reconstituted systems. The letter ‘a’ above the bars in this panel represents a significant difference from the CYP1A2 data measured at the highest activity (i.e. 100 mM). The letter ‘b’ above the bars represents a significant difference from the corresponding CYP2B4 data measured at its highest activity (i.e. 50 mM). (b) Effect of varying potassium acetate on PROD activity in simple and mixed reconstituted systems. (c) Effect of varying HEPES on PROD activity in simple and mixed reconstituted systems.