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，黑田黑藻的神经组织特异性单磷酸糖鞘脂FGL-IIb在其非还原端含有N-乙酰半乳糖，L-岩藻糖作为支链糖。抗FGL-Ⅱ b抗血清可与FGL-Ⅱ a和FGL-Ⅴ等多种膦酰糖脂发生免疫反应。通过GC-MS、NMR和化学方法，确定了FGL-Ⅱ a和FGL-Ⅴ的完整结构如下：因此，三种含甜菜酸的膦酰糖鞘脂具有与从Astrasia分离的所有其它膦酰糖鞘脂相同的骨架结构，GalNAcalphal->3Galbetal->4Glcbetal->1Ceramide。丙酮酸通过3、4位羟基与半乳糖末端发生构象连接.含膦酰鞘糖脂的甘草酸的细胞和亚细胞分布：在家兔中产生的抗FGL-IIb的抗血清仅染色了失神经症组织中的神经束。无神经元细胞体染色。免疫光镜下，轴突膜未被染色，但轴突周围的小圆细胞或细胞间成分似乎被染色。进行了免疫电镜检查.丙酮酸类膦酰鞘糖脂的生物学活性研究：其化学结构和组织分布的特殊性暗示了其在轴突生长或轴突成束中的神经生物学功能。进行了三条试验线。脂质或其抗血清对分离的失神经元轴突生长、克隆细胞纤维生长和失神经连合断端轴突生长的影响。抗FGL-Ⅱ b抗血清在最后一次实验中效果不明显。

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.