成像毛细管等电聚焦技术分析重组人促红素异质性

目的： 应用成像毛细管等电聚焦分析重组人促红素（rhEPO）的异构体和等电点。 方法： 首先对成像毛细管等电聚焦电泳技术进行了条件优化，并用优化的方法分析了rhEPO候选国家理化标准品和来自不同生产企业的10批rhEPO产品。根据成像毛细管等电聚焦电泳分析结果和体内生物学活性结果进一步分析了rhEPO糖链异构体与体内比活性的相关性。 结果： 优化的成像毛细管等电聚焦电泳技术可获得蛋白特异性图谱，可较好地分析重组人促红素的异构体和等电点。通过统计分析表明，成像毛细管等电聚焦电泳分析rhEPO的第2、3和4峰含量和体内生物学比活性之间存在正相关，第1和第6峰含量和体内比活性之间存在负相关。 结论： 成像毛细管等电聚焦技术能够分析重组人促红素的异构体和等电点，相关性分析显示异构体的组成与体内比活性相关，异质性分析在重组人促红素的质量控制中具有重要意义。

Objective: To develop an imaged capillary isoelectric focusing electrophoresis method for analysis of isomers and isoelectric point of recombinant human erythropoietin. Methods: This study first optimized the imaged capillary isoelectric focusing electrophoresis method, and then ana lyzed the rhEPO reference compound and ten batches of rhEPO products from different manufacturers using the optimized method. Based on the results from capillary isoelectric focusing electrophoresis and in vivo bioassay, we further analyzed the relation between rhEPO sugar chain isomers and bioactivities. Results: The isoelectric points and isomers of recombinant human erythropoietin were successfully analyzed by the developed imaged capillary isoelectric focusing electrophoresis method. Statistical analysis indicated that there was a positive correlation between the second, third and fourth peaks of rhEPO in imaged cIEF and bioactivity, and a negative correlation between the first and sixth peaks of rhEPO and bioactivity. Conclusion: This study demonstrated that the imaged capillary isoelectric focusing electrophoresis method could be used in analysis of isomers and electric point of rhEPO, and there was an association between isomer composition and in vivo specific activity, which suggests that heterogeneity analysis is significant in the quality control of recombinant human erythropoietin.