Intensive extrusion and occlusion of water in ganglioside micelles with thermal reversibility.
By using a shell-modeling analysis for small-angle scattering data of ganglioside micellar dispersion, we recently reported that the elevation of temperature induces a significant shrinkage of the hydrophilic region of the ganglioside micelle, suggesting that the oligosaccharide chains with sialic acid residues of ganglioside molecules change the conformation, sensitively responding to a change in temperature (Hirai et al., 1996. Biophys. J. 70:1761-1768; J. Phys. Chem. 100:11675-11680). We have carried out further analyses of the temperature dependence of the structural parameters reported previously, and we have found clear evidence of reversible extrusion and occlusion of a large amount of water in the hydrophilic region of the ganglioside micelle in the physiological temperature range of 6-60 degrees C. The present results suggest a remarkable function of ganglioside molecules: they change the hydrophilicity of the cell surface locally as a response to variations in temperature. This phenomenon might be involved in various surface events, such as cell-cell interaction and cell surface-protein interaction.
Hirai
M
M
Department of Physics, Gunma University, Maebashi, Japan. hirai@sun.aramaki.gunma-u.ac.jp
Takizawa
T
T
D000818:Animals; D001923:Brain Chemistry; D002236:Carbohydrate Conformation; D002417:Cattle; D005677:G(M1) Ganglioside / Q000737:chemistry; D005732:Gangliosides / Q000737:chemistry*; D007700:Kinetics; D008823:Micelles; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D009844:Oligosaccharides / Q000737:chemistry; D013816:Thermodynamics; D014867:Water
D005732:Gangliosides; D008823:Micelles; D009844:Oligosaccharides; D014867:Water; C021298:ganglioside, GD1a; D005677:G(M1) Ganglioside