Hitzemann R J
Chem Phys Lipids. 1987 Jan-Feb;43(1):25-38. doi: 10.1016/0009-3084(87)90014-4.
The effect(s) of bovine brain ganglioside-GM1 on the order of phosphatidylcholine-cholesterol membranes were studied using steady-state fluorescence polarization (FPZ) techniques with 1,6-diphenyl-1,3,5-hexatriene (DPH) as the membrane probe. In the absence of cholesterol, GM1 (30 mol%) increases both membrane order and the phase transition temperature of dipalmitoylphosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC) membranes. However, in the presence of cholesterol (0.3 or 0.5, cholesterol/phospholipid molar ratio), GM1 significantly decreases steady-state anisotropy (rs) at temperatures above the Tm for the particular phospholipid. This effect may, in part relate to a dilution of membrane cholesterol and is shared by bovine brain sphingomyelin (SM). GM1 (30 mol%) increases the order of 1-palmityl-2-oleyl-PC (POPC) membranes. However, in the presence of cholesterol (0.3 molar ratio) GM1 neither increases or decreases order. Thus, in cholesterol containing artificial membranes, the effect of GM1 depends on the phosphatidylcholine (PC) fatty acid composition and may not be evident from the effect of GM1 on pure PC membranes.
使用以1,6-二苯基-1,3,5-己三烯（DPH）作为膜探针的稳态荧光偏振（FPZ）技术，研究了牛脑神经节苷脂-GM1对磷脂酰胆碱-胆固醇膜有序性的影响。在不存在胆固醇的情况下，GM1（30摩尔%）可增加二棕榈酰磷脂酰胆碱（DPPC）和二肉豆蔻酰磷脂酰胆碱（DMPC）膜的膜有序性和相变温度。然而，在存在胆固醇（胆固醇/磷脂摩尔比为0.3或0.5）的情况下，GM1在特定磷脂的Tm以上温度下显著降低稳态各向异性（rs）。这种效应可能部分与膜胆固醇的稀释有关，并且牛脑鞘磷脂（SM）也有此效应。GM1（30摩尔%）可增加1-棕榈酰-2-油酰-PC（POPC）膜的有序性。然而，在存在胆固醇（摩尔比为0.3）的情况下，GM1既不增加也不降低有序性。因此，在含胆固醇的人工膜中，GM1的效应取决于磷脂酰胆碱（PC）的脂肪酸组成，并且从GM1对纯PC膜的效应中可能不明显。
