Membrane properties of binary and ternary systems of ganglioside GM1/dipalmitoylphosphatidylcholine/dioleoylphosphatidylcholine

• Published in: Colloids and surfaces, B, Biointerfaces B, Biointerfaces, 2004-04, Vol.34 (3), p.147-153
• Main Authors: Ohta, Yumiko, Yokoyama, Shoko, Sakai, Hideki, Abe, Masahiko
• Format: Article
• Language: English
• Subjects: 1,2-Dipalmitoylphosphatidylcholine - chemistry; G(M1) Ganglioside - chemistry; Microscopy, Atomic Force; Phosphatidylcholines - chemistry; Pressure; Surface Properties; Temperature
• ISSN: 0927-7765
• DOI: 10.1016/j.colsurfb.2003.11.005

The membrane properties of the ganglioside GM1 (GM1)/dioleoylphosphatidylcholine (DOPC) binary system and GM1/dipalmitoylphosphatidylcholine (DPPC)/DOPC ternary system were investigated using surface pressure measurements and atomic force microscopy (AFM), and the effect of surface pressure on the properties of the membranes was examined. Mixed GM1/DPPC/DOPC monolayers were deposited on mica using the Langmuir-Blodgett technique for AFM. GM1 and DOPC were immiscible and phase-separated. The AFM image of the GM1/DOPC (1:1) monolayer showed island-like GM1 domains embedded in the DOPC matrix. There was no morphological change on varying surface pressure. The surface pressure-area isotherm of the GM1/DPPC/DOPC (2:9:9) monolayer showed a two-step collapse as in the DPPC/DOPC (1:1) monolayer. The AFM image for the GM1/DPPC/DOPC monolayer showed DPPC and GM1 domains in the DOPC matrix, and the DPPC-rich phase containing GM1 showed a percolation pattern the same as the GM1/DPPC (1:9) monolayer. The percolation pattern in the GM1/DPPC/DOPC monolayer changed as the surface pressure was varied. The surface pressure-responsive change in morphology of GM1 was affected by the surrounding environment, suggesting that the GM1 localized in each organ has a specific role.