Scanning tunneling microscopy of the phosphatidylcholine bilayers

Abstract

The bare surface of the egg-PC bilayers after being dried at room temperature was observed by the STM and images with angstrom resolution were obtained. Results indicate that the lipid heads form islands of an average of 210 Å in diameter and 40 Å in separation on the bilayers and that each island contains about 170 lipid heads of 7.5 Å in diameter. The size of the lipid heads is correspondent with that calculated from the standard bond distances and the bond angles. The ordered distribution of the lipid heads in some areas may correspond to the ordered arrangement of the lipid heads on the egg-PC bilayers before being dried. The STM results also show that there exists the ripple phase in the egg-PC bilayers below its phase transition temperature.