Supported Lipid Bilayers with Phosphatidylethanolamine as the Major Component

Area of Science:

• Biophysics
• Materials Science
• Membrane Biophysics

Background:

• Phosphatidylethanolamine (PE) incorporation into model membranes is limited by its negative curvature.
• Supported lipid bilayers (SLBs) are crucial model systems for studying membrane properties.

Purpose of the Study:

• To develop guidelines for high-concentration phosphatidylethanolamine (PE) incorporation into supported lipid bilayers (SLBs).
• To investigate the binding of Ni2+ to PE in model membranes.
• To explore the potential of PE-containing SLBs for future applications.

Main Methods:

• Fluorescence-based techniques were used to analyze SLB quality.
• Lipid tail saturation and chain length were systematically varied.
• Ni2+ binding affinity to PE was quantified and compared to phosphatidylcholine.

Main Results:

• Lipids with fewer unsaturations and shorter saturated chains facilitate high-quality SLBs with minimized curvature.
• Up to 70 mol% PE was incorporated at room temperature and 90 mol% at 37 °C.
• Ni2+ binds 1000-fold tighter to PE than to phosphatidylcholine (PC) lipids.

Conclusions:

• Lipid tail design is critical for achieving high PE content in SLBs.
• PE-containing SLBs provide a robust platform for studying transition metal ion binding.
• This model system can be used to explore PE membrane physical properties and interactions with peptides.