Proteoliposome fusion to artificial lipid bilayer promoted by domains of polyunsaturated phosphatidylethanolamine

Abstract

There is growing concern regarding the fusion efficiency of proteoliposomes (PLs) as it is vital for the reconstitution of membrane proteins into artificial lipid bilayers. Recently, we discovered the formation of microdomains which act as a specific fusion site for PLs in a ternary lipid bilayer consisting of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and cholesterol (Chol). Based on our discovery of the microdomains, we propose that an increment of the microdomain area by manipulating the composition of lipid bilayers would ultimately lead to an improvement of PL fusion efficiency. In this study, we investigated the effects of didocosahexaenoyl-PE (22:6-PE), which has polyunsaturated fatty acids, on the fusion efficiency of PLs into a supported lipid bilayer comprising of PC, PE and Chol. We found that 22:6-PE increased the area fraction of microdomains and promoted the PL fusion efficiency compared with egg-derived PE.