Uniformly oriented gramicidin channels embedded in thick monodomain lecithin multilayers.

Area of Science:

• Biophysics
• Materials Science

Background:

• Phosphatidylcholine multilayers are common models for biological membranes.
• Gramicidin forms transmembrane ion channels.

Purpose of the Study:

• To create large, uniformly oriented lipid-gated gramicidin channel arrays.
• To enable detailed spectroscopic and diffraction studies of ion channels.

Main Methods:

• Low-temperature annealing (<60°C) and mechanical stressing of lipid-water multilayers.
• Monitoring alignment using conoscopy and polarized microscopy.
• Dissolving smectic defects during the alignment process.

Main Results:

• Obtained large (80 μm thick x 40 mm² area), monodomain, defect-free multilayers.
• Incorporated ~10^17 uniformly oriented gramicidin channels.
• Confirmed channel incorporation and orientation via circular dichroism (CD) spectroscopy.

Conclusions:

• Successfully aligned gramicidin-containing lipid multilayers.
• The oriented samples are suitable for advanced spectroscopic and diffraction analysis.
• This work facilitates research into ion channel structure and function.