Survival of recombinant erythropoietin in the circulation: the role of carbohydrates.
Survival of recombinant erythropoietin in the circulation: the role of carbohydrates.
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DOI：
10.1182/blood.v73.1.84.bloodjournal73184
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发表时间：
1989
期刊：
影响因子：
20.3
通讯作者：
M. Fukuda;Hiroshi Sasaki;L. López;M. Fukuda
中科院分区：
文献类型：
--
作者：
M. Fukuda;Hiroshi Sasaki;L. López;M. Fukuda
在转染的中国仓鼠卵巢细胞中产生的重组人促红细胞生成素的糖基化方式与人尿液中存在的促红细胞生成素的糖基化方式非常相似。为了确定碳水化合物在重组人促红细胞生成素体内稳定性中的作用，将[125 I]标记的重组促红细胞生成素静脉输注到大鼠体内。促红细胞生成素从血液中缓慢清除，半衰期约为2小时。用唾液酸酶处理重组人促红细胞生成素产生的去唾液酸促红细胞生成素在10分钟内从循环中迅速清除。这些数据表明，肝细胞的半乳糖结合蛋白参与了脱唾液酸红细胞生成素的清除。促红细胞生成素还含有具有少量N-乙酰乳糖胺重复的N-聚糖，其可以通过番茄凝集素亲和层析富集。凝集素结合的部分被清除到一个更大的程度比未分级的促红细胞生成素，而不结合凝集素的成分被发现是稳定的循环。从红细胞制备的真实N-乙酰乳糖胺重复序列（聚乳糖胺聚糖）也同样快速地从循环中清除至肝脏，并且这种清除与去唾液酸-α 1-酸性糖蛋白一致。这些结果表明：（a）重组促红细胞生成素的唾液酸是这种糖蛋白激素稳定循环所必需的;（B）具有三个以上乳糖胺重复单元的糖蛋白可以被肝细胞的半乳糖结合蛋白清除。
Recombinant human erythropoietin produced in transfected Chinese hamster ovary cells is glycosylated much the same way as the erythropoietin present in human urine. To determine the role of carbohydrates in the stability of recombinant human erythropoietin in vivo, [125I]-labeled recombinant erythropoietin was intravenously infused into rats. The erythropoietin was slowly cleared from the blood with a half-life of approximately two hours. Asialoerythropoietin, which was produced by treatment of recombinant human erythropoietin with sialidase, was found to be cleared rapidly from circulation within ten minutes. These data suggest that the galactose binding protein of hepatic cells is involved in the clearance of asialoerythropoietin. Erythropoietin also contains N-glycans with a few N-acetyllactosamine repeats, which can be enriched by tomato lectin affinity chromatography. The lectin-bound fraction was cleared to a larger extent than was the unfractionated erythropoietin, while the component that did not bind the lectin was found to be stable in the circulation. Authentic N-acetyllactosamine repeats (polylactosaminoglycans) prepared from erythrocytes were similarly rapidly cleared from the circulation to the liver, and this clearance was inhibitable with asialo-alpha 1-acid glycoprotein. These results suggest that (a) the sialic acid of the recombinant erythropoietin is necessary for this glycoprotein hormone to circulate stably and (b) glycoproteins with more than three lactosaminyl repeat units may be cleared by the galactose binding protein of hepatocytes.