Structural characterization of the disialogangliosides of murine peritoneal macrophages.
Structural characterization of the disialogangliosides of murine peritoneal macrophages.
复制标题
小鼠腹膜巨噬细胞二唾液酸神经节苷脂的结构特征。
DOI：
10.1093/glycob/7.8.1215
复制
发表时间：
1997
期刊：
影响因子：
4.3
通讯作者：
Reinhold,VN
中科院分区：
文献类型：
--
作者：
Yohe,HC;Ye,S;Reinhold,BB;Reinhold,VN
唾液酸鞘糖脂（神经节苷脂）越来越多地被认为是膜信号事件的调节剂。当鼠腹膜巨噬细胞在体内受到唾液酸酶敏感性单唾液酸神经节苷脂GMlb(cisGMl)作为主要成分的刺激时，巨噬细胞神经节苷脂模式的复杂性急剧增加。来自受刺激的鼠腹膜巨噬细胞的神经节苷脂被分离成单唾液酸和多唾液酸级分，并且通过酶促、化学和质谱方法对多唾液酸级分进行结构表征。聚唾液酸级分的所有可检测组分均被确定为二唾液酸神经节苷脂。用产气荚膜梭菌唾液酸酶处理多唾液酸部分主要产生唾液酸酶抗性单唾液酸神经节苷脂GMIa和少量asiaJoGMI。高碘酸盐氧化和质谱分析表明缺乏串联二唾液酸部分，这表明不存在 GD1b 或 GD1c (GDI) 实体。组合数据显示主要二唾液酸神经节苷脂由 GDla 实体组成，包括 IV3-NeuAc、II3NeuAc-GgOse4Cer、IV3-NeuGc、II3NeuAc-GgOse4Cer、IV3NeuAc、II3NeuGc-GgOse4Cer 和 IV3-NeuGc、II3NeuGc-GgOse4Cer。次要成分由 GD1α 实体、IV3NeuAc、III6NeuAcGgOse4Cer、IV3NeuGc、III6NeuGcGgOse4Cer 以及 GD1α 的位置异构体（NeuAc，NeuGc）组成。通过碰撞分析和串联质谱法鉴定了这些异构体成分。与之前的分析一致，所有聚唾液酸（二唾液酸）神经节苷脂的神经酰胺部分仅包含具有 C16 和 C24 脂肪酸部分的 C18 鞘氨醇。这些结果与巨噬细胞单唾液酸神经节苷脂的先前表征相结合，表明正常鼠巨噬细胞神经节苷脂生物合成沿着“a”神经节苷脂途径进行，例如GM3→GM2→GMla→GDlα，以及所提出的去唾液酸根-神经节苷脂或“α”途径，asialoGMl→GMlb→GDlα。完全唾液酸酶敏感的神经节苷脂的存在似乎是功能性小鼠腹膜巨噬细胞的特征，而它们在遗传受损的细胞中减少。
Sialoglycosphingolipids (gangliosides) have been increasingly implicated as regulators of membrane signaling events. Macrophage ganglioside patterns dramatically increase in complexity when murine peritoneal macrophages are stimulatedin vivowith the appearance of the sialidase-sensitive monosialoganglioside GMlb (cisGMl) as a major component Gangliosides from stimulated murine peritoneal macrophages were separated into monosialo and polysialo fractions and the polysialo fraction structurally characterized by enzymatic, chemical, and mass spectra methods. All detectable components of the polysialo fraction were determined to be disialogangliosides. Treatment of the polysialo fraction withClostridium perfringenssiali-dase produced mostly the sialidase-resistant monosialoganglioside, GMIa, and a minor amount of asiaJoGMI. Perio-date oxidation and mass spectrometry analyses demonstrated the lack of tandem disialo moieties which indicated the absence of GD1b or GD1c (GDI) entities. The combined data showed the major disialogangliosides consisted of GDla entities comprising IV3-NeuAc,II3NeuAc-GgOse4Cer, IV3-NeuGc,II3NeuAc-GgOse4Cer, IV3NeuAc,II3NeuGc-GgOse4Cer, and IV3-NeuGc,II3NeuGc-GgOse4Cer. Minor components consisted of GDlα entities, IV3NeuAc, III6NeuAcGgOse4Cer, IV3NeuGc, III6NeuGcGgOse4Cer, and also positional iso-mer(s) of GDlα(NeuAc, NeuGc). These isomeric components were identified by collision analysis and tandem mass spectrometry. Consistent with previous analyses, the cer-amide portion of all polysialo (disialo) gangliosides contained solely C18 sphingosine with C16 and C24 fatty acid moieties. These results, combined with the previous characterization of macrophage monosialogangliosides, indicate normal murine macrophage ganglioside biosynthesis proceeds along the “a” ganglioside pathway, e.g., GM3→GM2→GMla→GDlα, and the proposed asialogan-glioside or “α” pathway, asialoGMl→GMlb→GDlα. The presence of totally sialidase-sensitive gangliosides appears to be characteristic of functional murine peritoneal macrophages while they are reduced in genetically impaired cells.