Skip to main content
. 2008 Oct 22;75(1):92–100. doi: 10.1124/mol.108.050492

Fig. 5.

Fig. 5.

The ability of Q2 and quinine to compete for the drug binding sites of P-gp was investigated using an 125I-IAAP photo-affinity labeling assay. A, High Five crude membranes (25 μg) containing 125I-IAAP and increasing concentrations of quinine were photo-cross-linked for 20 min on ice, subjected to separation by SDS-PAGE, and binding was visualized by autoradiography. Incorporation of IAAP into P-gp remained unchanged with various concentrations of quinine. B, crude membranes (25 μg) containing 125I-IAAP and increasing concentrations of Q2 were photo-cross-linked for 20 min on ice, subjected to separation by SDS-PAGE, and binding was visualized by autoradiography. Incorporation of 125I-IAAP into P-gp was inhibited by Q2 in a concentration-dependent manner. C, autoradiographs were analyzed by ImageJ. GF120918 (10 μM) was used as a positive control (A,B).