Effect of cytochrome b5 and NADPH P-450 reductase on CPA and IFA 4-hydroxylase activities of Supersomes
| Lot# | CYPs | b5/P-450 | P-450-reductase 1-a | 4OH-CPA 1-b | 4OH-IFA 1-b |
|---|---|---|---|---|---|
| molar ratio | pmol/min/pmol P-450 | pmol/min/pmol P-450 | |||
| Panel A | |||||
| 5 | 3A4 | 0.4 | 0.5 ± 0.03 | 1.1 ± 0.12 | |
| E411-150 | 3A4 | 3.2 | 1.3 ± 0.03 | 2.1 ± 0.06 | |
| E421-150 | 3A4 + b5 | 1.5 | 3.2 | 1.4 ± 0.13 | 2.1 ± 0.03 |
| 3 | 3A4 + b5 | 1.8 | 11.3 | 2.8 ± 0.5 | 4.8 ± 0.7 |
| 10 | 3A4 + b5 | 3.6 | 15.0 | 3.0 ± 0.06 | 5.5 ± 0.7 |
| Panel B | |||||
| 7 | 2A6 | 1.2 | 1.1 ± 0.1 | 0.8 ± 0.05 | |
| 1 | 2A6 + b5 | 2.5 | 1.2 | 1.3 ± 0.1 | 0.8 ± 0.06 |
| 3 | 2B6 | 22.0 | 9.7 ± 1.7 | 0.4 ± 0.3 | |
| 1 | 2B6 + b5 | 2.2 | 29.9 | 13.1 ± 1.0 | 0.6 ± 0.13 |
| 4 | 2C8 | 0.6 | <0.2 | <0.2 | |
| 1 | 2C8 + b5 | 1.6 | 1.4 | 0.4 ± 0.01 | 0.3 ± 0.1 |
| 2 | 2C91-1501 | 0.7 | 0.5 ± 0.06 | <0.2 | |
| 1 | 2C91-1501 + b5 | 1.8 | 1.7 | 2.6 ± 0.64 | 0.6 ± 0.3 |
| 3 | 2C19 | 0.7 | 0.8 ± 0.2 | <0.2 | |
| 1 | 2C19 + b5 | 1.5 | 2.4 | 4.5 ± 0.63 | 1.4 ± 0.13 |
| 6 | 3A5 | 0.7 | 0.5 ± 0.1 | 0.3 ± 0.2 | |
| E431-150 | 3A5 + b5 | 1.5 | 1.5 | 1.6 ± 0.06 | 1.1 ± 0.07 |
| E461-150 | 3A7 | 4.7 | 0.9 ± 0.01 | 0.4 ± 0.04 | |
| 1 | 3A7 + b5 | 0.9 | 5.7 | 0.6 ± 0.06 | 0.5 ± 0.04 |
↵1-a nmoles of cytochrome c reduced/min/pmol P-450.
↵1-b 4-OH activity was determined at 2.0 mM substrate (CPA or IFA), expressed as mean ± S.E.M. of triplicate determinations.
↵1-150 Formulated Supersome: Two insect cells, one containing coexpressed P-450 and P-450 reductase and another containing human cytochrome b5, are mixed together to give the indicated b5/P-450 ratio.