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Updated: Dec 14, 2025
16:16
Genetically-encoded Molecular Probes to Study G Protein-coupled Receptors
Published on: September 13, 2013
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Structural definition of polyspecific compensatory ligand recognition by P-glycoprotein
Christina A Le1, Daniel S Harvey1, Stephen G Aller1
1Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Iucrj
|July 23, 2020
Summary
P-glycoprotein (Pgp) exhibits remarkable drug recognition adaptability. Aromatic amino acids in its drug-binding pocket enable compensatory binding, maintaining function despite mutations and challenging drug design.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- P-glycoprotein (Pgp/ABCB1/MDR1) is a key transporter in multidrug resistance and detoxification.
- Previous studies showed most Pgp mutations retained function, suggesting adaptive drug recognition.
Purpose of the Study:
- To investigate the role of aromatic residues in Pgp's drug-binding pocket (DBP).
- To explore compensatory drug recognition mechanisms in Pgp.
Main Methods:
- Phenylalanine-to-alanine scanning mutagenesis of Pgp.
- Crystallography to determine drug-binding sites.
- ATPase activity assays to assess transporter function.
Main Results:
- Mutations Y303A and Y306A revealed a novel drug-binding site (site 2).
- Mutation F724A showed a drug-binding site shifted significantly from the original site.
- ATPase kinetics were altered, but transporter remained active and inhibited by BDE-100.
Conclusions:
- Aromatic amino acids in the Pgp DBP are crucial for compensatory drug recognition.
- This adaptability underlies polyspecific transport and poses challenges for drug design.
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