Investigation of F508del CFTR unfolding and a search for stabilizing small molecules.

Publisher: Elsevier Country of Publication: United States NLM ID: 0372430 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1096-0384 (Electronic) Linking ISSN: 00039861 NLM ISO Abbreviation: Arch Biochem Biophys Subsets: MEDLINE

Publication: <2000- > : San Diego, CA : Elsevier
Original Publication: New York, NY : Academic Press

Cystic Fibrosis Transmembrane Conductance Regulator*/chemistry ; Cystic Fibrosis Transmembrane Conductance Regulator*/genetics ; Cystic Fibrosis Transmembrane Conductance Regulator*/metabolism ; Small Molecule Libraries*/pharmacology ; Small Molecule Libraries*/chemistry; Humans ; Kinetics ; Protein Unfolding ; Protein Stability ; Cystic Fibrosis/metabolism ; Cystic Fibrosis/genetics ; Cystic Fibrosis/drug therapy ; Mutation

Mutation of phenylalanine at position 508 in the cystic fibrosis transmembrane conductance regulator (F508del CFTR) yields a protein unstable at physiological temperatures that is rapidly degraded in the cell. This mutation is present in about 90% of cystic fibrosis patients, hence there is great interest in compounds reversing its instability. We have previously reported the expression of the mutated protein at low temperature and its purification in detergent. Here we describe the use of the protein to screen compounds present in a library of Federal Drug Administration (FDA) - approved drugs and also in a small natural product library. The kinetics of unfolding of F508del CFTR at 37 °C were probed by the increase in solvent-exposed cysteine residues accessible to a fluorescent reporter molecule. This occurred in a bi-exponential manner with a major (≈60%) component of half-life around 5 min and a minor component of around 60 min. The faster kinetics match those observed for loss of channel activity of F508del CFTR in cells at 37 °C. Most compounds tested had no effect on the fluorescence increase, but some were identified that significantly slowed the kinetics. The general properties of these compounds, and any likely mechanisms for inducing stability in purified CFTR are discussed. These experimental data may be useful for artificial intelligence - aided design of CFTR-specific drugs and in the identification of stabilizing additives for membrane proteins (in general).
(Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Keywords: CFTR; Cystic fibrosis; Fluorescence; Ion channel; Protein folding; Screening

126880-72-6 (Cystic Fibrosis Transmembrane Conductance Regulator)
0 (Small Molecule Libraries)
0 (CFTR protein, human)

Date Created: 20240614 Date Completed: 20240715 Latest Revision: 20240925

20240926

10.1016/j.abb.2024.110050

38876247