TIME AND TEMPERATURE-DEPENDENT AGGREGATION BEHAVIOR OF THE GANGLIOSIDE GM1 IN AQUEOUS-SOLUTION

Gangliosides are marked amphiphiles with several ramified sugar rings and a ceramide moiety. Therefore they form micelles in aqueous solutio n. This aggregation behavior is studied with static and dynamic light scattering and small angle X-ray scattering. The shape and the size of the GM1 micelles in dependence of time and temperature are investigat ed. Some data have been published recently where two stable states for the micelles are found. This bistability is said to be achieved by te mperature rise from room temperature up to 55 degrees C. The authors d id not find such an internal structural change of the micelle in the e xperiments. Instead the authors found some large aggregates of the gan glioside in parallel to the micelle caused by the low solubility of th is system at room temperature. These aggregates are dissolved quickly with increasing temperature or slowly with time at room temperature. S o the variation of the scattering intensity is explainable by dissolvi ng the large particles, meanwhile the structure of the GM1 micelles is the same all the time. (C) 1998 Elsevier Science Ireland Ltd. All rig hts reserved.