Title: Characteristics of Liposomes Made by Phosphatidylethanolamine
Abstract: Liposomes are vesicles made of lipid bilayer and used in study as a model of biological membranes. Phosphatidylethanolamine (PE) is a major phospholipid of most prokaryotes. PE is a phospholipid that is the second most present after phosphatidylcholine (PC) in the living world. In this study, the liposomes were prepared by gentle hydration method with varying the ratio of the lipids to clarify whether PE affects the form of the liposomes. As a result, the liposomes containing much PE were observed more and smaller than the liposomes not containing much PE. Furthermore, the liposomes reproducing the lipid composition of the cell membranes of E. coli were observed more and smaller than the liposomes reproducing the lipid composition of the cell membranes of human red blood cells. Therefore, it was suggested that PE decreased the size of vesicles and ancestors of prokaryotes might have been able to evolve in eukaryotes by discarding PE and acquiring PC.