title: Kinetics of transfer of gangliosides from their micelles to dipalmitoylphosphatidylcholine vesicles.
abstract: Two aspects of the kinetics of transfer of ganglioside from micelles to dipalmitoylphosphatidylcholine vesicles have been examined: (i) The first aspect is the rate of transfer of ganglioside from micelles at very low ganglioside/phospholipid ratios. Under these conditions the rate of incorporation into vesicles is independent of the vesicle concentration, indicating that transfer occurs by diffusion of ganglioside molecules through the aqueous phase and not by collision of micelles and vesicles. The initial transfer of monosialoganglioside is slower (t 1/2 = 2 h) than that of trisialoganglioside (t 1/2 = 0.5 h). The rate of transfer decreases during the transfer process. This decrease in rate depends on the character of the micelles and not on the ganglioside content of acceptor vesicles. The initial rate of transfer decreases sharply with decreasing temperature. (ii) The second aspect is the rate of transfer of ganglioside from micelles to phospholipid vesicles at high ganglioside/phospholipid ratios. In the presence of excess ganglioside, the level of incorporation into vesicles saturates when the ganglioside content of the vesicles reaches 12-15 mol %. This saturation level is not markedly dependent on the number of sialic acid residues in the ganglioside.
mesh_terms: D003102:Colloids; D005732:Gangliosides / Q000378:metabolism*; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism*; D008823:Micelles; D011663:Pulmonary Surfactants; D013696:Temperature
chemical_list: D003102:Colloids; D005732:Gangliosides; D008051:Lipid Bilayers; D008823:Micelles; D011663:Pulmonary Surfactants