Figure 9.

Topology of epitope-tagged full-length Pgp. Proteins encoding the C-terminal half (A) or full-length (B) MDR1-Pgp tagged with the P reporter between TM8 and TM9 was expressed in oocytes and subjected to PK digestion as in Figure 2. Polypeptides migrated at 73 kDa (for C-terminal constructs) and 150 kDa (for full-length MDR1-Pgp). The smear of full-length protein was likely due in part to immunoprecipitation artifact. Protease-protected P-reactive fragments generated by protease digestion are indicated by downward arrows.