Carlsson S R, Sasaki H, Fukuda M
J Biol Chem. 1986 Sep 25;261(27):12787-95.
Structures of O-linked oligosaccharides of leukosialin isolated from K562 erythroid, HL-60 promyelocytic, and HSB-2 T-lymphoid cell lines were examined. Leukosialin was isolated by specific immunoprecipitation from cells which were metabolically labeled with [3H]glucosamine, and glycopeptides were isolated after Pronase digestion. O-Linked oligosaccharides were released by alkaline borohydride treatment, and the structures of purified oligosaccharides were elucidated by specific exoglycosidase digestion, Smith degradation, and methylation anaylsis. Oligosaccharides from K562 cells were found to be GalNAcOH, Gal beta 1----3GalNAcOH, NeuNAc alpha 2----6GalNAcOH, NeuNAc alpha 2----3Gal beta 1----3GalNAcOH, Gal beta 1----3(NeuNAc alpha 2----6)GalNAcOH, and NeuNAc alpha 2----3Gal beta 1----3(NeuNAc alpha 2----6)GalNAcOH. On the other hand, oligosaccharides from HL-60 and HSB-2 cells were found to be NeuNAc alpha 2----3Gal beta 1----3GalNAcOH, NeuNAc alpha 2----3Gal beta 1----4GlcNAc beta 1----6(Gal beta 1----3)GalNAcOH, Gal beta 1----4GlcNAc beta 1----6(NeuNAc alpha 2----3)Gal beta 1----3)GalNAcOH, and NeuNAc alpha 2----3Gal beta 1----4GlcNAc beta 1----6(NeuNAc alpha 2----3Gal beta 1----3)GalNAcOH. These results clearly indicate that leukosialin can be differently glycosylated with O-linked chains, and each erythroid or myeloid (and T-lymphoid) cell line expresses a characteristic set of O-linked oligosaccharides which differ in core structures as well as in sialylation.
对从K562红系细胞、HL - 60早幼粒细胞和HSB - 2 T淋巴细胞系中分离出的白细胞唾液酸蛋白的O - 连接寡糖结构进行了研究。通过特异性免疫沉淀从用[³H]葡糖胺进行代谢标记的细胞中分离白细胞唾液酸蛋白，经链霉蛋白酶消化后分离糖肽。通过碱性硼氢化钠处理释放O - 连接寡糖，并通过特异性外切糖苷酶消化、史密斯降解和甲基化分析阐明纯化寡糖的结构。发现来自K562细胞的寡糖为GalNAcOH、Galβ1→3GalNAcOH、NeuNAcα2→6GalNAcOH、NeuNAcα2→3Galβ1→3GalNAcOH、Galβ1→3(NeuNAcα2→6)GalNAcOH和NeuNAcα2→3Galβ1→3(NeuNAcα2→6)GalNAcOH。另一方面，发现来自HL - 60和HSB - 2细胞的寡糖为NeuNAcα2→3Galβ1→3GalNAcOH、NeuNAcα2→3Galβ1→4GlcNAcβ1→6(Galβ1→3)GalNAcOH、Galβ1→4GlcNAcβ1→6(NeuNAcα2→3)Galβ1→3)GalNAcOH和NeuNAcα2→3Galβ1→4GlcNAcβ1→6(NeuNAcα2→3Galβ1→3)GalNAcOH。这些结果清楚地表明，白细胞唾液酸蛋白可以被不同的O - 连接链糖基化，并且每个红系或髓系（以及T淋巴细胞系）细胞系都表达一组特征性的O - 连接寡糖，它们在核心结构以及唾液酸化方面存在差异。
