Fig. 11.

MS spectrum from the fragmentation of DLTDCLLVEMEK of the PIC-adducted peptide with a mass increment of 147 Da. CYP2E1 was reconstituted with reductase and PEITC in the presence and absence of NADPH. The samples were digested with trypsin and analyzed by LC-MS/MS and SEQUEST software as described in Materials and Methods. The figure shows the profile for the doubly charged ion with m/z 778.7 for the modified peptide ²⁶⁴DLTDCLLVEMEK²⁷⁵ with a mass increment of 147 amu and modification at the cysteine residue. The inset shows the b ion and y ions of the adducted peptide.