Structural titration of receptor ion channel GLIC gating by HS-AFM Academic Article uri icon

Overview

MeSH Major

  • Image Processing, Computer-Assisted
  • Microscopy, Atomic Force

abstract

  • © 2018 National Academy of Sciences.All Rights Reserved. Gloeobacter violaceus ligand-gated ion channel (GLIC), a protongated, cation-selective channel, is a prokaryotic homolog of the pentameric Cys-loop receptor ligand-gated ion channel family. Despite large changes in ion conductance, small conformational changes were detected in X-ray structures of detergent-solubilized GLIC at pH 4 (active/desensitized state) and pH 7 (closed state). Here, we used high-speed atomic force microscopy (HS-AFM) combined with a buffer exchange system to performstructural titration experiments to visualize GLIC gating at the single-molecule level under native conditions. Reference-free 2D classification revealed channels in multiple conformational states during pH gating. We find changes of protein-protein interactions so far elusive and conformational dynamics much larger than previously assumed. Asymmetric pentamers populate early stages of activation, which provides evidence for an intermediate preactivated state.

publication date

  • October 9, 2018

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC6187180

Digital Object Identifier (DOI)

  • 10.1073/pnas.1805621115

PubMed ID

  • 30181288

Additional Document Info

start page

  • 10333

end page

  • 10338

volume

  • 115

number

  • 41