Okano M, Suga H, Masuda S, Nagao M, Narita H, Ikura K, Sasaki R
Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Japan.
Biosci Biotechnol Biochem. 1993 Nov;57(11):1882-5. doi: 10.1271/bbb.57.1882.
We isolated erythropoietin (Epo) from anemic-rat serum with 1.3 x 10(6)-fold purification and 38% recovery using immunoaffinity chromatography. The isolated Epo migrated in SDS polyacrylamide gel with a molecular size of 37 kDa. Biological properties of rat Epo were compared with those of human Epo using target cells of primate and murine origins. When murine cells were used as target cells for assaying Epo, rat Epo stimulated proliferation of the cells with a 50% lower potency than did human Epo. The activity of rat Epo on human cells was only 25% of that of human Epo. Studies of Epo binding to the receptor indicated that rat and human Epos were not distinguishable in binding to murine cells; however, rat Epo bound to the receptor on human cells with an affinity much lower than that of human Epo. Rat Epo was digested with N-glycanase. Complete removal of N-linked sugars converted the native Epo to the deglycosylated form with 18 kDa. The in vitro activity of deglycosylated Epo was 2.5-fold higher than that of the native Epo.
我们使用免疫亲和层析从贫血大鼠血清中分离出促红细胞生成素（Epo），纯化倍数为1.3×10⁶倍，回收率为38%。分离出的Epo在SDS聚丙烯酰胺凝胶中迁移，分子大小为37 kDa。使用灵长类和鼠源的靶细胞比较了大鼠Epo与人Epo的生物学特性。当使用鼠细胞作为检测Epo的靶细胞时，大鼠Epo刺激细胞增殖的效力比人Epo低50%。大鼠Epo对人细胞的活性仅为人Epo的25%。Epo与受体结合的研究表明，大鼠Epo和人Epo在与鼠细胞结合方面没有区别；然而，大鼠Epo与人细胞上的受体结合时，亲和力远低于人Epo。大鼠Epo用N-糖苷酶消化。完全去除N-连接糖后，天然Epo转化为18 kDa的去糖基化形式。去糖基化Epo的体外活性比天然Epo高2.5倍。
