Authors
Biswa P Mishra, Ben Cristofori-Armstrong, Elena Budusan, Mimi Golder, Neville J Butcher, Junyu Liu, Theo Crawford, Yanni K-Y Chin, Anneka Pereira Schmidt, Xinying Jia, Taylor B Smallwood, Richard J Clark, Jan P Wurm, Lachlan D Rash, Mehdi Mobli
Published in
Angewandte Chemie (International ed. in English). Volume 65. Issue 19. Pages e23977. May 04, 2026. Epub Mar 25, 2026.
Abstract
Proton-gated acid-sensing ion channels (ASICs) are emerging therapeutic targets for ischemia-related conditions such as stroke and myocardial infarction. Although structural data exist for ASIC1a, key aspects of ligand recognition and modulation remain unresolved. Using multidimensional solution-state NMR spectroscopy, we show that the principal ligand-binding region of ASICs, the thumb domain, forms an independently folded unit that at neutral pH adopts a native-like conformation resembling the resting state of the channel. By integrating high-resolution biophysical analyses of ligand binding to the isolated thumb domain with electrophysiological measurements on full-length ASIC1a, we distinguished molecular interactions that determine binding affinity from those governing functional efficacy. This approach revealed that dynorphin A acts as a competitive antagonist of ASIC1a. Furthermore, NMR-based pKa determination of individual acidic residues demonstrated generally elevated values across the isolated thumb domain, supporting the presence of an extended acid-sensing network rather than a single dominant pH sensor. These findings establish the isolated thumb domain as a powerful model for dissecting ASIC ligand interactions and pH sensitivity in solution, providing mechanistic insights and enabling structure-based drug discovery of therapeutic modulators for ASICs and related ion channels.
PMID:
41879033
Bibliographic data and abstract were imported from PubMed on 17 Sep 2026.
Read full publication at:
Please sign in
to see all details.
Advertisement
Stats
- Recommendations n/a n/a positive of 0 vote(s)
- Views 7
- Comments 0