Structural study of the O-linked sugar chains of human leukocyte tyrosine phosphatase CD45
Structural study of the O-linked sugar chains of human leukocyte tyrosine phosphatase CD45
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DOI：
10.1046/j.1432-1327.1998.2510288.x
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发表时间：
1998-01-15
期刊：
影响因子：
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通讯作者：
Gahmberg, CG
中科院分区：
文献类型：
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作者：
Furukawa, K;Funakoshi, Y;Gahmberg, CG
人白细胞表面糖蛋白CD 45的O-连接糖链在（NaBH 4）-H-3存在下通过β-消除释放为氚标记的寡糖。Mono Q柱层析显示，它们包括中性（64%）和酸性（36%）寡糖，后者被节杆菌尿素酶处理转化为中性的。通过连续外切糖苷酶消化和甲基化分析在Bio-Gel P-4柱上分级分离的每种寡糖的结构研究显示，人白细胞CD 45主要含有核心1和核心2寡糖，其中15%在不同的延伸中被聚（N-乙酰乳糖胺）链修饰。CD 45由几种亚型组成，这些亚型是在细胞表面唾液酸残基被高碘酸盐/（NaBH 4）-H-3处理后分离的。通过链霉蛋白酶消化然后用温和的碱性硼氢化物处理获得的氚标记的糖肽/寡糖的混合物的生物凝胶P-6柱色谱法显示，唾液酸化的核心2寡糖的分布在CD 45亚型之间是不同的。
The O-linked sugar chains of the human leukocyte cell surface glycoprotein CD45 were released as tritium-labeled oligosaccharides by beta-elimination in the presence of (NaBH4)-H-3. Mono Q column chromatography revealed that they comprise neutral (64%) and acidic (36%) oligosaccharides, the latter of which were converted to neutral ones by Arthrobacter ureafaciens sialidase treatment. Structural studies of each oligosaccharide fractionated on a Bio-Gel P-4 column by sequential exoglycosidase digestion and by methylation analysis revealed that human leukocyte CD45 contains mainly core 1 and core 2 oligosaccharides, 15% of which are modified with poly (N-acetyllactosamine) chains in different extensions. CD45 consists of several isoforms which were isolated after cell surface sialic acid residues were labeled by periodate/(NaBH4)-H-3 treatment. Bio-Gel P-6 column chromatography of a mixture of the tritium-labeled glycopeptide/oligosaccharides obtained by pronase-digestion followed by mild alkaline borohydride treatment showed that distribution of the sialylated core 2 oligosaccharides is different among CD45 isoforms.