Structure and Function of Phosphonosphingoglycolipids Containing Pyruvylated Galactose.

1.Fgl-IIa和Fgl-V的结构：我们以前的研究表明，黑线海兔神经组织中的一种特异的单磷酸神经鞘糖脂Fgl-IIb的非还原端含有丙酮化半乳糖，而L岩藻糖是一种分枝糖。抗FGL-IIb抗血清与包括FGL-IIa和FGL-V在内的许多其他磷脂发生免疫反应。用GC-MS、核磁共振和化学方法确定了Fgl-Ⅱa和fgl-V的完整结构如下：3个含丙酮酸的磷脂酰胆碱酯的骨架结构与从海兔属(Aplysia，GalNAcalphal-&gt；3Galbetal-&gt；4Glcbetal-&gt；1Ceramide.)中分离得到的所有其他磷脂酸磷脂具有相同的骨架结构丙酮酸通过3-羟基和4-羟基构型连接到末端半乳糖上。含丙酮酸磷脂糖脂的细胞和亚细胞分布：抗FGL-IIb抗血清仅在海兔组织中染色神经束。未见神经元胞体染色。免疫光镜下，轴索膜未被染色，但轴突周围的小圆形细胞或细胞间质似被染色。进行免疫电子显微镜检查。含丙酮酸磷脂的生物活性研究：其化学结构和组织分布的特殊性暗示了它们在轴突生长或轴突颤动中的神经生物学功能。进行了三条线的实验。脂质或其抗血清对分离的海兔神经元轴突生长、克隆细胞的纤维生长和海兔连合神经断端的轴突生长的影响。在上一次实验中，抗FGL-IIb抗血清显示出较小的效果。

1. Structures of FGL-IIa and FGL-V : Our previous studies revealed that one of the nervous tissuespecific monophosphonoglycosphingolipid FGL-IIb of Aplysia kurodai contains pyruvylated galactose at its non-reducing end and L-fucose as a branched sugar. Anti-FGL-IIb antiserum reacts immunologically with many other phosphonoglycolipids including FGL-IIa and FGL-V. By GC-MS, NMR and chemical methods, the complete structures of FGL-IIa and FGL-V were determined as follows :Thus three pyruvic acid containing phosphonoglycosphingolipids have been shown to have the back bone structure common to all other phosphonoglycosphingolipids isolated from Aplysia, GalNAcalphal->3Galbetal->4Glcbetal->1Ceramide. Pyruvic acid is linked to terminal galactose through 3 and 4 hydroxyl by sconfiguration.2. Cellular and subcellular distribution of pyruvic acid containing phosphonosphingoglycolipids : Antiserum raised against to FGL-IIb in the rabbit stained only nerve bundles in the tissues of Aplysia. No neuronal cell bodies were stained. Immuno-light microscopically, axonal membranes were not stained but small round cells surrounding the axons or intercellular elements seemed to be stained. Immuno-electron microscopic examination has being carried out.3. Studies on biological activities of pyruvate containing phosphonosphingoglycolipids : Their peculiarities in the chemical structures and the tissue distribution imply their neurobiological functions in axonal growth or axonal fasciculation. Three lines of experiment have been carried out. Effects of the lipids or their antisera on axonal growth of isolated Aplysia neuron, on fiber outgrowth from clonal cells and on axonal outgrowth from cut-end of the commissural nerve of Aplysia. Anti FGL-IIb antiserum showed a little effects in the last experiment.