Sonnino S, Acquotti D, Cantu L, Chigorno V, Valsecchi M, Casellato R, Masserini M, Corti M, Allevi P, Tettamanti G
Department of Medical Chemistry and Biochemistry, University of Milan Medical School, Italy.
Chem Phys Lipids. 1994 Feb;69(2):95-104. doi: 10.1016/0009-3084(94)90031-0.
GM1 ganglioside containing a hydroxylated fatty acid moiety, GM1(OH), was synthesized starting from lyso-GM1 and D-(+)-2-hydroxystearic acid. The aggregative, geometrical and distribution properties of GM1(OH) were compared with those of stearic acid containing GM1 ganglioside; laser light scattering measurements, differential scanning calorimetry and fluorescence spectroscopy were used. GM1 and GM1(OH) are present in solution as micelles with a hydrodynamic radius of 58.7 and 60.0 A, and molecular mass of 470 and 570 kDa, respectively. The surface area occupied by the monomer of GM1(OH) at the lipid-water interface of the aggregate was calculated to be 117 A2, which is 3 A2 lower than that determined for GM1. Proton NMR analyses of GM1 and GM1(OH) suggest different three-dimensional structures at the ganglioside lipid-water interface. Both GM1(OH) and GM1 inserted into dipalmitoylphosphatidylcholine (DPPC) vesicles undergo segregation phenomena, with the formation of ganglioside-enriched microdomains, but GM1(OH) shows a higher degree of dispersion in the DPPC matrix and exerts a lower rigidifying effect than does GM1.
从溶血神经节苷脂GM1和D-(+)-2-羟基硬脂酸出发，合成了含有羟基化脂肪酸部分的神经节苷脂GM1(OH)。将GM1(OH)的聚集、几何形状和分布特性与含有硬脂酸的神经节苷脂GM1的特性进行了比较；采用了激光散射测量、差示扫描量热法和荧光光谱法。GM1和GM1(OH)在溶液中均以胶束形式存在，其流体力学半径分别为58.7 Å和60.0 Å，分子量分别为470 kDa和570 kDa。GM1(OH)单体在聚集体脂质-水界面处占据的表面积经计算为117 Å2，比GM1的测定值低3 Å2。GM1和GM1(OH)的质子核磁共振分析表明，在神经节苷脂脂质-水界面处存在不同的三维结构。GM1(OH)和GM1插入二棕榈酰磷脂酰胆碱(DPPC)囊泡中均会发生分离现象，形成富含神经节苷脂的微区，但GM1(OH)在DPPC基质中表现出更高的分散度，且比GM1发挥更低程度的刚性化作用。
