酵母系统表达TPO与E.coli表达TPO N端结构域生物半衰期比较

为了探讨血小板生成素（ＴＰＯ）糖基化与其生物半衰期的关系，首先纯化了巴氏毕赤酵母系统分泌表达的人ＴＰＯ成熟肽和大肠杆菌表达的人ＴＰＯＮ端结构域蛋白．纯化产物经Ｗｅｓｔｅｒｎｂｌｏｔ鉴定和活性分析后，两种蛋白以相同浓度或相同活性单位给Ｗｉｓｔｅｒ大鼠尾静脉注射，利用酶联免疫分析（ＥＬＩＳＡ）和ＴＦ１细胞测定不同时间点实验动物血浆中ＴＰＯ浓度或生物学活性，求出两种ＴＰＯ的生物半衰期（ｔ１／２）值．结果显示，以相同浓度和相同活性单位给药，ＴＰＯ成熟肽的ｔ１／２均比其Ｎ端结构域的长，前者分别是后者的１．６５倍和１．２７倍．

The Comparison between Biological Half life of TPO Mature Peptide Expressed in Piochia pastoris and TPO N terminal Domain Expressed in E.coli

In order to investigate the relation of thrombopoietin (TPO) glycosylation and biological half life,human thrombopoietin mature peptide expressed by Piochia pastoris and TPO N terminal domain protein expressed by E.coli were purified.After Western blot analysis and activity assay,two kinds of proteins were injected into Wister rats with 50 μg/rat or 5×10 5 U/rat by tail vein injection respectively.TPO level in plasma and biological activity were detected at different time points by means of ELISA and TF1 cell line proliferation.Biological half life ( t 1/2 ) of two kinds of TPO were calculated.The results indicated that the half body clearance of TPO mature peptide was longer than that of TPO N terminal domain protein with the same activity unit and same concentration.The former were 1 65 times and 1 27 times as long as the latter respectively.