Erythropoietin metabolism and the influence of carbohydrate structure.
Erythropoietin metabolism and the influence of carbohydrate structure.
复制标题
促红细胞生成素代谢和碳水化合物结构的影响。
DOI：
10.1159/000417883
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发表时间：
1989
影响因子：
--
通讯作者：
Fukuda,MN
中科院分区：
文献类型：
--
作者：
Fukuda,M;Sasaki,H;Fukuda,MN
Erythropoietin is a glycoprotein hormone with a molecular weight of 31 kilodaltons, with 40% of its molecular mass accounted for by carbohydrates. These carbohydrates have been known to consist of one O-linked and three N-linked oligosaccharides [1, 2]. Erythropoietin is synthesized in the kidney and circulates in the blood to stimulate red cell proliferation and differentiation in the bone marrow. This hormonal activity is abolished in vivo after sialic acid residues are removed [3, 4]. But, the asialoerythropoietin has full activity when the assay is done in vitro [5]. The apparent loss of activity of the asialoerythropoietin in vivo can be explained by the rapid clearance from the circulation by hepatic cells [5]. When the terminal sialic acid residues are removed from the oligosaccharides, galactose residues become the new terminal sugars. These galactose-terminated glycoproteins may then be recognized by receptors present in hepatocytes and are internalized by endocytosis, followed by digestion with lysosomes [6]. Thus, it is apparent that the erythropoietin should be fully glycosylated, in particular, sialylated well to accomplish the hormone action in vivo.
