scholarly journals Defining the Drug-binding Site in the Human Multidrug Resistance P-glycoprotein Using a Methanethiosulfonate Analog of Verapamil, MTS-verapamil

2001 ◽  
Vol 276 (18) ◽  
pp. 14972-14979 ◽  
Author(s):  
Tip W. Loo ◽  
David M. Clarke
Keyword(s):  
Multidrug Resistance ◽  
Binding Site ◽  
Drug Binding ◽  
Drug Binding Site ◽  
P Glycoprotein

scholarly journals Modulation of drug-stimulated ATPase activity of human MDR1/P-glycoprotein by cholesterol

2006 ◽  
Vol 401 (2) ◽  
pp. 597-605 ◽  
Author(s):  
Yasuhisa Kimura ◽  
Noriyuki Kioka ◽  
Hiroaki Kato ◽  
Michinori Matsuo ◽  
Kazumitsu Ueda
Keyword(s):  
Atpase Activity ◽  
Molecular Mass ◽  
Binding Site ◽  
Drug Binding ◽  
Soluble Form ◽  
Strongly Correlated ◽  
Drug Binding Site ◽  
Hydrophobic Compounds ◽  
P Glycoprotein ◽  
Human Mdr1

MDR1 (multidrug resistance 1)/P-glycoprotein is an ATP-driven transporter which excretes a wide variety of structurally unrelated hydrophobic compounds from cells. It is suggested that drugs bind to MDR1 directly from the lipid bilayer and that cholesterol in the bilayer also interacts with MDR1. However, the effects of cholesterol on drug–MDR1 interactions are still unclear. To examine these effects, human MDR1 was expressed in insect cells and purified. The purified MDR1 protein was reconstituted in proteoliposomes containing various concentrations of cholesterol and enzymatic parameters of drug-stimulated ATPase were compared. Cholesterol directly binds to purified MDR1 in a detergent soluble form and the effects of cholesterol on drug-stimulated ATPase activity differ from one drug to another. The effects of cholesterol on Km values of drug-stimulated ATPase activity were strongly correlated with the molecular mass of that drug. Cholesterol increases the binding affinity of small drugs (molecular mass <500 Da), but does not affect that of drugs with a molecular mass of between 800 and 900 Da, and suppresses that of valinomycin (molecular mass >1000 Da). Vmax values for rhodamine B and paclitaxel are also increased by cholesterol, suggesting that cholesterol affects turnover as well as drug binding. Paclitaxel-stimulated ATPase activity of MDR1 is enhanced in the presence of stigmasterol, sitosterol and campesterol, as well as cholesterol, but not ergosterol. These results suggest that the drug-binding site of MDR1 may best fit drugs with a molecular mass of between 800 and 900 Da, and that cholesterol may support the recognition of smaller drugs by adjusting the drug-binding site and play an important role in the function of MDR1.

scholarly journals Evidence for the Interaction of A3 Adenosine Receptor Agonists at the Drug-Binding Site(s) of Human P-glycoprotein (ABCB1)

2019 ◽  
Vol 96 (2) ◽  
pp. 180-192 ◽  
Author(s):  
Biebele Abel ◽  
Dilip K. Tosh ◽  
Stewart R. Durell ◽  
Megumi Murakami ◽  
Shahrooz Vahedi ◽  
...  
Keyword(s):  
Binding Site ◽  
Adenosine Receptor ◽  
Drug Binding ◽  
Adenosine Receptor Agonists ◽  
Receptor Agonists ◽  
Drug Binding Site ◽  
P Glycoprotein ◽  
A3 Adenosine Receptor

Functional analysis of P-glycoprotein mutants identifies predicted transmembrane domain 11 as a putative drug binding site

Biochemistry ◽  
1993 ◽  
Vol 32 (16) ◽  
pp. 4185-4194 ◽  
Author(s):  
Shama Kajiji ◽  
France Talbot ◽  
Kart Grizzuti ◽  
Valerie Van Dyke-Phillips ◽  
Michael Agresti ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Binding Site ◽  
Transmembrane Domain ◽  
Drug Binding ◽  
Drug Binding Site ◽  
P Glycoprotein

scholarly journals Major Photoaffinity Drug Binding Sites in Multidrug Resistance Protein 1 (MRP1) Are within Transmembrane Domains 10–11 and 16–17

2001 ◽  
Vol 276 (15) ◽  
pp. 12324-12330 ◽  
Author(s):  
Roni Daoud ◽  
Michel Julien ◽  
Philippe Gros ◽  
Elias Georges
Keyword(s):  
Multidrug Resistance ◽  
Binding Site ◽  
Drug Binding ◽  
Amino Acid Residues ◽  
Multidrug Resistance Protein 1 ◽  
Drug Binding Site ◽  
Molecular Masses ◽  
Membrane Spanning ◽  
Linker Domain ◽  
Membrane Spanning Domains

MRP1 is an ABC (or ATP binding cassette) membrane transport protein shown to confer resistance to structurally dissimilar drugs. Studies of MRP1 topology suggested the presence of a hydrophobic N-domain with five potential membrane-spanning domains linked to an MDR1-like core (MSD1-NBD1-L1-MSD2-NBD2) by an intracellular linker domain (L0). MRP1-mediated multidrug resistance is thought to be due to enhanced drug efflux. However, little is known about MRP1-drug interaction and its drug binding site(s). We previously developed several photoreactive probes to study MRP1-drug interactions. In this report, we have used eight MRP1-HA variants that were modified to have hemagglutinin A (HA) epitopes inserted at different sites in MRP1 sequence. Exhaustive in-gel digestion of all IAARh123 photoaffinity-labeled MRP1-HA variants revealed the same profile of photolabeled peptides as seen for wild type MRP1. Photolabeling of the different MRP1-HA variants followed by digestion with increasing concentrations of trypsin orStaphylococcus aureusV8 protease (1:800 to 1:5 w/w) and immunoprecipitation with anti-HA mAb identified two small photolabeled peptides (∼6–7 kDa) from MRP1-HA(574) and MRP1-HA(1222). Based on the location of the HA epitopes in the latter variants together with molecular masses of the two peptides, the photolabeled amino acid residues were localized to MRP1 sequences encoding transmembranes 10 and 11 of MSD1 (Ser542-Arg593) and transmembranes 16 and 17 of MSD2 (Cys1205-Glu1253). Interestingly, the same sequences in MRP1 were also photolabeled with a structurally different photoreactive drug, IACI, confirming the significance of transmembranes 10, 11, 16 and 17 in MRP1 drug binding. Taken together, the results in this study provide the first delineation of the drug binding site(s) of MRP1. Furthermore, our findings suggest the presence of common drug binding site(s) for structurally dissimilar drugs.

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