An ion transport switch based on light-responsive conformation-dependent G-quadruplex transmembrane channels

Area of Science:

• Supramolecular chemistry
• Biophysical chemistry
• Membrane transport

Background:

• G-quadruplexes are stable nucleic acid structures with potential for molecular recognition.
• Azobenzene derivatives can undergo photoisomerization, enabling light-controlled molecular switching.
• Selective ion transport across lipid membranes is crucial for biological processes and synthetic systems.

Purpose of the Study:

• To develop a light-responsive system for controlled ion transport.
• To engineer G-quadruplex channels with azobenzene moieties for light-gating.
• To achieve selective transport of potassium ions (K+) across artificial lipid membranes.

Main Methods:

• Synthesis of azobenzene-incorporated lipophilic G-quadruplex structures.
• Incorporation of these channels into artificial lipid bilayers.
• Investigation of ion transport using electrophysiological techniques.
• Characterization of light-induced conformational changes in the G-quadruplex channels.

Main Results:

• Demonstrated successful incorporation of azobenzene-G-quadruplex channels into lipid membranes.
• Showcased light-induced conformational changes in the channels upon UV-Vis irradiation.
• Achieved light-controlled, selective transport of potassium ions (K+) through the channels.
• Established a correlation between channel conformation and ion permeability.

Conclusions:

• A novel light-responsive ion transport switch based on G-quadruplex channels has been successfully developed.
• The system offers a smart and selective approach for modulating K+ transport across lipid membranes.
• This work opens new avenues for light-gated molecular transport and smart biomaterials.