Nakamura K, Suzuki M, Taya C, Inagaki F, Yamakawa T, Suzuki A
Department of Membrane Biochemistry, Tokyo Metropolitan Institute of Medical Science.
J Biochem. 1991 Nov;110(5):832-41. doi: 10.1093/oxfordjournals.jbchem.a123667.
The disialogangliosides of WHT/Ht mouse thymomas, which were obtained by subcutaneous transplantation of a thymoma that developed spontaneously in a WHT/Ht mouse, were purified and characterized. From the results of sugar-composition analysis, a permethylation study, enzymatic hydrolysis followed by TLC-immunostaining, negative-ion fast atom bombardment mass spectrometry (FAB/MS), and 1H-NMR spectroscopy, the structure of one of the five purified disialogangliosides was determined to be IV3 alpha(NeuGc alpha 2-8NeuGc)-Gg4Cer. The other 4 disialogangliosides were tentatively characterized on the basis of sialidase treatment followed by TLC-immunostaining with cholera toxin B subunit and anti-Gg4Cer antibody to be IV alpha(NeuAc alpha-NeuGc)-Gg4Cer, IV alpha(NeuGc alpha-NeuAc)-Gg4Cer, IV alpha NeuAc,II3 alpha NeuAc-Gg4Cer, and IV alpha NeuGc,II3 alpha NeuGc-Gg4Cer. In addition, another component exhibiting one spot on TLC was a mixture of IV alpha NeuGc,II3 alpha NeuAc-Gg4Cer and IV alpha NeuAc,II3 alpha NeuGc-Gg4Cer. Then the occurrence of these gangliosides in WHT/Ht mouse thymocytes was examined. As one of two major disialogangliosides, the thymocytes contained IV3 alpha(NeuGc alpha 2-8NeuGc)-Gg4Cer, which was characterized with a mass spectrum and mass chromatograms obtained by micro high-performance liquid chromatography-FAB/MS. The other major disialoganglioside was tentatively characterized to be II3 alpha-(NeuGc alpha-NeuGc)-Gg4Cer by sialidase treatment followed by TLC-immunostaining. A sialidase-susceptible monosialoganglioside, IV3 alpha NeuGc-Gg4Cer [GM1b(NeuGc)], had been reported to be characteristic of mouse immune tissues [Nakamura, K. et al. (1988) J. Biochem, 103, 201-208]. Taken together, the results suggest that the pathway from Gg4Cer to IV3 alpha(NeuGc alpha 2-8NeuGc)-Gg4Cer through GM1b(NeuGc) is quite active in mouse immune tissues.
通过皮下移植在WHT/Ht小鼠中自发形成的胸腺瘤而获得的WHT/Ht小鼠胸腺瘤的二唾液酸神经节苷脂，被进行了纯化和表征。根据糖组成分析、全甲基化研究、酶解后进行薄层层析免疫染色、负离子快原子轰击质谱（FAB/MS）以及1H-核磁共振光谱的结果，确定了五种纯化的二唾液酸神经节苷脂之一的结构为IV3α（NeuGcα2-8NeuGc）-Gg4Cer。另外4种二唾液酸神经节苷脂根据唾液酸酶处理后用霍乱毒素B亚基和抗Gg4Cer抗体进行薄层层析免疫染色进行了初步表征，分别为IVα（NeuAcα-NeuGc）-Gg4Cer、IVα（NeuGcα-NeuAc）-Gg4Cer、IVαNeuAc，II3αNeuAc-Gg4Cer和IVαNeuGc，II3αNeuGc-Gg4Cer。此外，在薄层层析上呈现一个斑点的另一种成分是IVαNeuGc，II3αNeuAc-Gg4Cer和IVαNeuAc，II3αNeuGc-Gg4Cer的混合物。然后检测了这些神经节苷脂在WHT/Ht小鼠胸腺细胞中的存在情况。作为两种主要的二唾液酸神经节苷脂之一，胸腺细胞中含有IV3α（NeuGcα2-8NeuGc）-Gg4Cer，通过微高效液相色谱-FAB/MS获得的质谱和质量色谱图对其进行了表征。另一种主要的二唾液酸神经节苷脂通过唾液酸酶处理后进行薄层层析免疫染色初步表征为II3α-（NeuGcα-NeuGc）-Gg4Cer。据报道，一种对唾液酸酶敏感的单唾液酸神经节苷脂IV3αNeuGc-Gg4Cer [GM1b（NeuGc）]是小鼠免疫组织的特征[中村，K.等人（1988年）《生物化学杂志》，103，201-208]。综合来看，结果表明从Gg4Cer通过GM1b（NeuGc）到IV3α（NeuGcα2-8NeuGc）-Gg4Cer的途径在小鼠免疫组织中相当活跃。
