Supramolecular Transmembrane Ion Channels Formed by Multiblock Amphiphiles

Area of Science:

• Supramolecular Chemistry
• Membrane Biophysics
• Materials Science

Background:

• Transmembrane proteins, including ion channels, are vital for cellular processes and are drug targets.
• Synthetic molecules mimicking ion channel functions hold potential for sensing, manipulation, and industrial applications.

Purpose of the Study:

• To design and develop novel multiblock amphiphiles (MAs) capable of forming self-assembled supramolecular nanopores in lipid bilayers.
• To investigate and control the transmembrane ion transport properties of these MAs in response to external stimuli.

Main Methods:

• Synthesis of multiblock amphiphiles (MAs) with oligo(ethylene glycol) and oligo(phenylene-ethynylene) units.
• Incorporation of MAs into lipid bilayer membranes to form self-assembled nanopores.
• Stimuli-responsive design of MAs incorporating bulky groups, phosphate esters, or fluorine atoms.
• Characterization of MA self-assembly, structure, and ion transport properties.
• All-atom molecular dynamics simulations for mechanism studies.

Main Results:

• MAs self-assemble into functional supramolecular nanopores within lipid bilayers, enabling transmembrane ion transport.
• Ion transport properties were controllably modulated by mechanical force, ligand binding (aromatic amines), and voltage.
• Developed MAs with phosphate ester groups that respond to aromatic amine ligands in living cells.
• Demonstrated voltage-responsive ion transport using MAs with fluorinated hydrophobic units.
• Extended design principles to create a transmembrane anion transporter.

Conclusions:

• Multiblock amphiphiles offer a versatile platform for creating artificial ion channels with tunable transmembrane transport properties.
• Stimuli-responsive MAs provide precise control over ion transport, with significant implications for synthetic biology and medicine.
• The molecular design principles discussed pave the way for advanced biomimetic materials for sensing and therapeutic interventions.