Figure 5.

Nitration of drug efflux pumps by DOXO and NO−DOXOs in HT29-dx cells. HT29-dx cells were incubated for 24 h with 5 μM DOXO, 4, or 5. Afterward, cells were lysed, and the whole cellular lysate was immunoprecipitated with an antinitrotyrosine polyclonal antibody. The immunoprecipitated proteins were subjected to Western blotting, using an anti-Pgp or an anti-MRP3 antibody (see the Supporting Information). An aliquot of cells lysate before immunoprecipitation was analyzed for total P-gp and MRP3. The expression of the housekeeping protein GAPDH (glyceraldehydes-3-phosphate dehydrogenase) was measured as a control of equal loading. The experiment is representative of three similar experiments.