Pore-Exposed Tyrosine Residues of P-Glycoprotein Are Important Hydrogen-Bonding Partners for Drugs

Author(s)
Yaprak Doenmez Cakil, Narakorn Khunweeraphong, Zahida Parveen, Diethart Schmid, Matthias Artaker, Gerhard F. Ecker, Harald H. Sitte, Oliver Pusch, Thomas Stockner, Peter Chiba
Abstract

The multispecific efflux transporter, P-glycoprotein, plays an important role in drug disposition. Substrate translocation occurs along the interface of its transmembrane domains. The rotational C2 symmetry of ATP-binding cassette transporters implies the existence of two symmetry-related sets of substrateinteracting amino acids. These sets are identical in homodimeric transporters, and remain evolutionary related in full transporters, such as P-glycoprotein, in which substrates bind preferentially, but nonexclusively, to one of two binding sites. We explored the role of pore-exposed tyrosines for hydrogen-bonding interactions with propafenone type ligands in their preferred binding site 2. Tyrosine 953 is shown to form hydrogen bonds not only with propafenone analogs, but also with the preferred site 1 substrate rhodamine123. Furthermore, an accessory role of tyrosine 950 for binding of selected propafenone analogs is demonstrated. The present study demonstrates the importance of domain interface tyrosine residues for interaction of small molecules with P-glycoprotein.

Organisation(s)
External organisation(s)
Medizinische Universität Wien, Abdul Wali Khan University Mardan
Journal
Molecular Pharmacology
Volume
85
Pages
420-428
No. of pages
9
ISSN
0026-895X
DOI
https://doi.org/10.1124/mol.113.088526
Publication date
12-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
301207 Pharmaceutical chemistry
Keywords
ASJC Scopus subject areas
Molecular Medicine, Pharmacology
Portal url
https://ucrisportal.univie.ac.at/en/publications/38c8e276-2466-4e24-abe0-5a68815f37c2