2026/03/09 by Ivan Maslov, Valentin Borshchevskiy, Iván Pérez +5 · 1 voice
Biochemistry, Genetics and Molecular Biology · #Receptor Mechanisms and Signaling #Advanced Fluorescence Microscopy Techniques #Cellular transport and secretion
paper · pdf · doi:10.1038/s42004-026-01941-8
openalex publication_date 2026/03/09 · openalex created_date 2026/03/10 · openalex updated_date 2026/07/29
Abstract The functional complexity of G protein-coupled receptors (GPCRs) arises from their structural dynamics, spanning timescales from nanoseconds to minutes. Single-molecule Förster Resonance Energy Transfer (smFRET) enables direct observation of these dynamics in individual receptors, either freely diffusing in solution, using confocal microscopy, or immobilized on surfaces, using Total Internal Reflection Fluorescence (TIRF) camera-based microscopy. However, these modalities are limited to distinct timescales – faster than milliseconds or slower than hundreds of milliseconds, respectively. To overcome these limitations, we employed smFRET with Anti-Brownian Electrokinetic (ABEL) trapping to extend the observation time of untethered human A 2A adenosine receptors (A 2A AR) reconstituted in lipid nanodiscs from milliseconds to seconds. We characterized conformational heterogeneity in apo and ligand-bound A 2A AR and updated previous estimates of dwell times for long-lived receptor states from milliseconds to hundreds of milliseconds. Our results highlight the power of ABEL-FRET to probe GPCRs dynamics and offer valuable insights into GPCR conformational landscapes.