Dynamic ligand-induced conformational rearrangements in P-glycoprotein as probed by fluorescence resonance energy transfer spectroscopy.

ABSTRACT: P-glycoprotein (Pgp), a member of the ATP-binding cassette transporter family, functions as an ATP hydrolysis-driven efflux pump to rid the cell of toxic organic compounds, including a variety of drugs used in anticancer chemotherapy. Here, we used fluorescence resonance energy transfer (FRET) spectroscopy to delineate the structural rearrangements the two nucleotide binding domains (NBDs) are undergoing during the catalytic cycle. Pairs of cysteines were introduced into equivalent regions in the N- and C-terminal NBDs for labeling with fluorescent dyes for ensemble and single-molecule FRET spectroscopy. In the ensemble FRET, a decrease of the donor to acceptor (D/A) ratio was observed upon addition of drug and ATP. Vanadate trapping further decreased the D/A ratio, indicating close associ

SUBMITTER: Verhalen B 

PROVIDER: S-EPMC3256922 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature