TABLE 1

NH₂-terminal amino acid sequence of band d obtained by cleaving CYP3A4 with formic acid

Cleavage of CYP3A4 with formic acid was performed as described in the legend to Fig. 6. The fragments obtained were separated on SDS-PAGE and electroblotted onto PVDF membrane according to the method of Kyhse-Andersen (1984). After staining the proteins on the PVDF membrane with Coomassie Brilliant Blue R-250, band d was removed and washed with MilliQ water (Millipore). Then, the membrane was dried and subjected to N-terminal amino acid sequence analysis by a protein sequencer (Applied Biosystems, Foster City, CA). The amino acid at position 218 is a possible site sensitive to cleavage with formic acid.