Using Phospholipase A2 to Create Air-Stable Supported Lipid Bilayers

Supported lipid bilayer platform has a potential to be applied as anti-biofouling surface and biosensor interface because of the high bio-compatability and the ability to keep biomolecule's orientation for specific ligand-receptor interaction. However, conventional supported lipid bilayers may delaminate as they are exposed to air-water interface, causing the difficulty in their long-term storage and real-life application. Therefore, developing methods to maintain the integrity and fluidity of lipid bilayers after dried and rehydrated can significantly broaden the application. In this work, we observed that a type of pheripheral enzyme, phosholipase A₂ (PLA₂), can induce the formation of a branch-liked gel domain in the supported lipid bilayers. The branch-liked gel domains give aid to the preservation of lipid bilayers when it is exposed to air-water interface., The diffusivity of the rehydrated lipid bilayers measured by the fluorescence recovery after photobleaching technique was found to be comparable to the one before dried, indicating that the fluidity of the lipid bilayer is nearly unchanged. Our work suggests that the gel domain induced by PLA₂ may play an important role in the retention of supported lipid bilayers, which leads to a new methodology of air-stable lipid bilayers formation.