Electrophysiology of Epithelial Sodium Channel (ENaC) Embedded in Supported Lipid Bilayer Using a Single Nanopore Chip

Muhammad Shuja Khan, Noura Sayed Dosoky, Ghulam Mustafa, Darayas Patel, Bakhrom Berdiev, John Dalton Williams

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

Nanopore-based technologies are highly adaptable supports for developing label-free sensor chips to characterize lipid bilayers, membrane proteins, and nucleotides. We utilized a single nanopore chip to study the electrophysiology of the epithelial Na+ channel (ENaC) incorporated in supported lipid membrane (SLM). An isolated nanopore was developed inside the silicon cavity followed by fusing large unilamellar vesicles (LUVs) of DPPS (1,2-dipalmitoyl-sn-glycero-3-phosphoserine) and DPPE (1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine) to produce a solvent-free SLM with giga-ohm (Gω) sealed impedance. The presence and thickness of SLM on the nanopore chip were confirmed using atomic force spectroscopy. The functionality of SLM with and without ENaC was verified in terms of electrical impedance and capacitance by sweeping the frequency from 0.01 Hz to 100 kHz using electrochemical impedance spectroscopy. The nanopore chip exhibits long-term stability for the lipid bilayer before (144 h) and after (16 h) incorporation of ENaC. Amiloride, an inhibitor of ENaC, was utilized at different concentrations to test the integrity of fused ENaC in the lipid bilayer supported on a single nanopore chip. The developed model presents excellent electrical properties and improved mechanical stability of SLM, making this technology a reliable platform to study ion channel electrophysiology.

Original languageEnglish (US)
Pages (from-to)13680-13688
Number of pages9
JournalLangmuir
Volume33
Issue number47
DOIs
StatePublished - Nov 28 2017

All Science Journal Classification (ASJC) codes

  • General Materials Science
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

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