STRUCTURE OF THE O-GLYCANS IN GLYCAM-1, AN ENDOTHELIAL-DERIVED LIGAND FOR L-SELECTIN
STRUCTURE OF THE O-GLYCANS IN GLYCAM-1, AN ENDOTHELIAL-DERIVED LIGAND FOR L-SELECTIN
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DOI：
10.1074/jbc.270.20.12035
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发表时间：
1995-05-19
影响因子：
4.8
通讯作者：
ROSEN, SD
中科院分区：
文献类型：
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作者：
HEMMERICH, S;LEFFLER, H;ROSEN, SD
L-选择素，白细胞选择素，介导循环白细胞与内皮的碳水化合物依赖性附着，在迁移到组织中之前，其在炎性白细胞运输和淋巴细胞归巢到淋巴结中起作用。从先前的工作来看，L-选择素与内皮相关糖蛋白配体GlyCAM-1和CD 34的结合需要寡糖唾液酸化、硫酸化和可能的岩藻糖基化，我们最近确定了GlyCAM-1中的一个主要封端基团为6'硫酸化唾液酸刘易斯x，这是一种可能满足所有这些要求的新结构。在本研究中，我们使用代谢放射性标记、植物凝集素结合和糖苷酶二聚体结合高pH阴离子交换色谱来确定GlyCAM-1的β-消除链的完整结构。GlyCAM-1中的大多数0-聚糖含有T-抗原，即Gal β 1->GalNAc，其被掺入核心-α结构中，即Gal β 1->3[GlcNAc β 1->6]GalNAc或具有额外GlcNAc残基的更大核心结构。基于核心-2，两种0-聚糖的结构被确定为：[图表]讨论了这些结构和更复杂的O-聚糖与L-选择素结合的含义，
L-selectin, the leukocyte selectin, mediates the carbohydrate dependent attachment of circulating leukocytes to endothelium, preceding emigration into tissues, It functions in inflammatory leukocyte trafficking and in lymphocyte homing to lymph nodes, From previous work, the binding of L-selectin to endothelial-associated glycoprotein ligands, GlyCAM-1 and CD34, requires oligosaccharide sialylation, sulfation, and probably fucosylation, We have recently identified a major capping group in GlyCAM-1 as 6' sulfated sialyl Lewis x, a novel structure which potentially satisfies all of these requirements, In the present study, we define the complete structure of beta-eliminated chains of GlyCAM-1 using metabolic radiolabeling, plant lectin binding, and glycosidase digestions in conjunction with high pH anion-exchange chromatography. The majority of the O-glycans in GlyCAM-1 contain the T-antigen, i.e. Gal beta 1-->GalNAc, which is incorporated into the core-a structure, i.e. Gal beta 1-->3[GlcNAc beta 1-->6]GalNAc or larger core structures with additional GlcNAc residues, The structures of two O-glycans, based on core-2, were determined to be:[GRAPHICS]The implications of these structures and more complex O-glycans for binding by L-selectin are discussed,