Multidrug resistance (MDR) in cancer and other diseases is frequently associated with transmembrane efflux proteins, one of which is P-glycoprotein (P-gp). Over-expression of P-gp in cancer cells increases the efflux of therapeutic drugs rendering them ineffective. In order to re-sensitize multidrug resistant cancers to chemotherapy, we have found potential inhibitors of P-gp by in silico screening methods, and several of these inhibitors were shown to successfully overcome MDR in the drug resistant DU145TXR prostate cancer cell line. The best of the identified hit compounds were further investigated with regard to the mechanism of inhibition using ATPase activity assays and electron spin resonance spectroscopy (ESR). Using a spin-labeled ATP analog and ESR spectroscopy, we assessed the effects of the identified inhibitors on ATP binding to P-gp. In the ATPase activity assays, it was found that the environment of P-gp is extremely important for drug discovery efforts using purified membrane proteins.

Degree Date

Spring 5-15-2021

Document Type


Degree Name



Biological Sciences


Pia Vogel

Subject Area

Biochemistry, Biophysics, Life Sciences



Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

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