ESI LC-MS/MS analysis of CYP2E1 incubated with ad without reductase in the presence of PIC or PEITC
Incubations and separations were as described under Materials and Methods.
| Reaction system | Treatment | Observed Mass | Modifying Mass Unitd |
|---|---|---|---|
| P450 alone (control) | Methanol | 54838a | —– |
| P450 alone | 25 µM PEITC | 54838a | —– |
| P450 alone | 10 µM PIC | 54837a, 54982a | 145 |
| P450+reductase (control) methanol | 54843a | —– | |
| P450+reductase | 25 µM PEITC | 54842 ± 1b | —– |
| P450+reductase | 25µM PEITC+NADPH | 54843 ± 1c, 55018 ± 6c | 175 ± 6 |
ESI, electrospray ionization; LC-MS/MS, liquid chromatography-tandem mass spectrometry; PEITC, phenethyl isothiocyanate.
↵a Data represent the mean of two injections in which the difference between the protein masses for the two injections was within three mass units.
↵b,cData represent the mean and standard deviations from three and four injections, respectively.
↵d Difference in the protein mass between nonadducted and adducted peaks observed in each deconvoluted spectra.