STRUCTURAL & CELL BIOLOGY IN CARDIOVASCULAR DISEASE

刺激小鼠腹腔巨噬细胞的神经节苷脂， 分为单唾液酸和多唾液酸派别， 聚唾液酸部分的实体的特征通过质量 光谱法 样品制备为全甲基化衍生物 评估更多的结构细节并提高灵敏度 NIS研究前用唾液酸酶治疗表明， 大多数聚唾液酸组分具有唾液酸酶抗性GMla型 具有少量的去唾液酸GM 1的碱。 详细结构分析 高碘酸盐氧化和质谱分析表明， 不存在任何串联的二唾液酸基部分。 主要的神经节苷脂在 由GDla实体组成的聚唾液酸组分，其包含 IV3-NeuAc、113 NeuAc-GgOse4Cer、IV3-NeuGc、113 NeuAc-GgOse4Cer、 IV3 NeuAc，] II3 NeuGc-GgOse4Cer和IV3-NeuGc，H3 NeuGc-GgOse4Cer。 的 次要组分包括GDIa实体，IV 3 NeuAc， 1116 NeuAcGgOse 4Cer、IV 3 NeuGc、1116 NeuGcGgOse 4Cer和 GDla（NeuAc，NeuGc），其中位置异构体不能是 测定 与先前的分析一致， 所有聚唾液酸神经节苷脂仅含有C18鞘氨醇， 和C24脂肪酸部分。 这些结果表明， 沿着“A”神经节苷脂途径（例如，GM3->GM2->Gma->Gdla） 和所提出的去唾液酸神经节侧或“OC”途径， 去唾液酸GM->GM[lb]-+GDl（x. p敏感神经节苷脂似乎是 小鼠免疫细胞的特征。

Gangliosides from stimulated murine peritoneal macrophages were separated into monosialo and polysialo factions and the structural character of entities of the polysialo fraction were examined by mass spectrometry. The samples were prepared as permethylated derivatives to evaluate greater structural detaiI and improve sensitivity. Treatment with sialidase prior to NIS studies indicated that the majority of the polysialo fraction had a sialidase-resistant GMla type base with a minor amount of asialoGM1. Detailed structural analyses by periodate oxidation and mass spectrometry indicated a complete absence of any tandem disialo moieties. The major gangliosides in the polysialo fraction consisted of GDla entities comprising IV3-NeuAc,113NeuAc-GgOse4Cer, IV3-NeuGc,113NeuAc-GgOse4Cer, IV3NeuAc,]II3NeuGc-GgOse4Cer, and IV3-NeuGc,H3NeuGc-GgOse4Cer. The minor components consisted of GDIa entities, IV3NeuAc, 1116NeuAcGgOse4Cer, IV3NeuGc, 1116NeuGcGgOse4Cer, and GDla(NeuAc,NeuGc) where the positional isomer(s) could not be determined. Consistent with previous analyses, ceramide portions of all polysialo gangliosides contained solely C18 sphingosine with C16 and C24 fatty acid moieties. These results suggest biosynthesis to proceed along the "a" ganglioside pathway (e.g., GM3-->GM2->Gma->Gdla) and the proposed asialoganglio side or "oc" pathway, asialoGM->GM[lb-+GDl(x. The p sensitive gangliosides appears to be characteristic of murine immune cells.