Comparison of the abilities of cDNA-expressed P450 to activate aflatoxin B1 to a gene mutagen
| Enzyme | Cell Line | (A) Minimum Effective Concentration | (B) P450 Content | Product of A × B | Reference No. |
|---|---|---|---|---|---|
| ng/ml | pmol/mg microsomes | ||||
| CYP1A1 | h1A1 | 62 | 12 | 740 | 49 |
| CYP1A2 | h1A2/Hyg | 10.5 | 1.4 | 15 | 53 |
| CYP2A6 | 2A3/Hol | 7 | 554-a | 385 | 46 |
| CYP2B6 | h2B6 | 38 | 55 | 2090 | This study |
| CYP3A4 | 3A4/Hol | 88 | 1.7 | 150 | 53 |
The minimum effective concentration was calculated as the aflatoxin concentration where the dose response curve crossed the 99% upper confidence limit for the historical negative control data base (7 × 10−6). All cell lines seem to have similar negative control mutant frequencies.
↵4-a C. Crespi, unpublished data.