Identification of binding sites for ivacaftor on the cystic fibrosis transmembrane conductance regulator

Onofrio Laselva; Zafar Qureshi; Zhi-Wei Zeng; Evgeniy V. Petrotchenko; Mohabir Ramjeesingh; C. Michael Hamilton; Ling-Jun Huan; Christoph H. Borchers; Régis Pomès; Robert Young; Christine E. Bear

iScience (Jun 2021)

Identification of binding sites for ivacaftor on the cystic fibrosis transmembrane conductance regulator

Onofrio Laselva,
Zafar Qureshi,
Zhi-Wei Zeng,
Evgeniy V. Petrotchenko,
Mohabir Ramjeesingh,
C. Michael Hamilton,
Ling-Jun Huan,
Christoph H. Borchers,
Régis Pomès,
Robert Young,
Christine E. Bear

Affiliations

Onofrio Laselva: Programme in Molecular Medicine, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy
Zafar Qureshi: Department of Chemistry, Simon Fraser University, Burnaby, Canada
Zhi-Wei Zeng: Programme in Molecular Medicine, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, Canada
Evgeniy V. Petrotchenko: Segal Cancer Proteomics Center, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Canada; Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
Mohabir Ramjeesingh: Programme in Molecular Medicine, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
C. Michael Hamilton: Department of Chemistry, Simon Fraser University, Burnaby, Canada
Ling-Jun Huan: Programme in Molecular Medicine, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
Christoph H. Borchers: Segal Cancer Proteomics Center, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Canada; Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia; Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada
Régis Pomès: Programme in Molecular Medicine, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, Canada
Robert Young: Department of Chemistry, Simon Fraser University, Burnaby, Canada
Christine E. Bear: Programme in Molecular Medicine, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Physiology, University of Toronto, Toronto, Canada; Department of Biochemistry, University of Toronto, Toronto, Canada; Corresponding author

Journal volume & issue: Vol. 24, no. 6
p. 102542

Abstract

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Summary: Ivacaftor (VX-770) was the first cystic fibrosis transmembrane conductance regulator (CFTR) modulatory drug approved for the treatment of patients with cystic fibrosis. Electron cryomicroscopy (cryo-EM) studies of detergent-solubilized CFTR indicated that VX-770 bound to a site at the interface between solvent and a hinge region in the CFTR protein conferred by transmembrane (tm) helices: tm4, tm5, and tm8. We re-evaluated VX-770 binding to CFTR in biological membranes using photoactivatable VX-770 probes. One such probe covalently labeled CFTR at two sites as determined following trypsin digestion and analysis by tandem-mass spectrometry. One labeled peptide resides in the cytosolic loop 4 of CFTR and the other is located in tm8, proximal to the site identified by cryo-EM. Complementary data from functional and molecular dynamic simulation studies support a model, where VX-770 mediates potentiation via multiple sites in the CFTR protein.

Published in iScience

ISSN: 2589-0042 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Science
Website: http://www.cell.com/iscience/home

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