Specific adhesion and lipid exchange between complementary vesicle and supported or Langmuir film

The interaction between complementary vesicle and a supported or Langmuir monolayer containing either barbituric acid (BAR) or 2,4,6-triaminopyrimidine (TAP) derivatives has been investigated. The quartz crystal microbalance (QCM) technique permits one to detect vesicle adhesion and to quantify the process. The selectivity of the interaction and its dependence on various factors have been investigated: ionic strength. pH, concentration of recognition sites, and state of the supported membrane. Moreover, the Langmuir film balance technique has shown that lipid exchange and possibly hemifusion occur between the complementary vesicle and the Langmuir monolayer at the air water interface. The results point to an electrostatic contribution to the vesicle adhesion, and they also support a picture according to which hydrogen bonding stabilizes the adhesion between complementary vesicles and supported membranes by a local arrangement of the complementary lipids in the contact area.