重组人尿激酶原冻干产品的稳定性

目的：探讨重组人尿激酶原（rhPro-UK）冻干产品的稳定性。方法：采用S-2444发色底物法测定贮存在4℃和-20℃的rhPro-UK冻干产品的活性、单链比例随时间的变化规律；用SDS-PAGE及RP-HPLC肽图分析贮存在-20℃的rhPro-UK冻干产品的结构与组成的变化。结果：4℃保存3年后的rhPro-UK冻干产品的总活性和单链比例基本没有变化，但随着贮存时间的延长，有部分产品降解，如贮存78个月的样品，总活性可降低13％～15％；-20℃保存78个月后，rhPro-UK冻干产品的总活性和单链比例未见明显变化。SDS-PAGE及RP-HPLC肽图图谱显示，-20℃贮存78个月后的rhPro-UK冻干产品的组成和结构没有变化。结论：rhPro-UK冻干产品在4℃的贮存寿命可达3年；长期贮存于-20℃的rhPro-UK冻干产品，其总活性、单链比例及结构组成非常稳定。

Stability of Lyopbilized Recombinant Human Prourokinase

Objective： To study the stability of lyophilized recombinant human prourokinase（rhPro-UK）. Methods： The lyophilized rhPro-UK products stored at 4℃ and -20℃ were analyzed by S-2444 chromogenic assay to measure the total activity and the inactive single-chain zymogen form （scu-PA） ratio of the rhPro-UK. SDS-PAGE and RP-HPLC peptide mapping methods were used to determine the alterations of rhPro-UK composition and structure when stored at -20℃. Results： There was no influence in the activity and scu-PA ratio of lyophilized rhPro-UK stored at 4℃ during 3 years, but 13%-15% of its activity was lost when last for 78 months. Almost no alteration of the activity and scu-PA ratio was detected when the lyophilized products were kept at -20℃ for 78 months. At the same time, the results of SDS-PAGE and RP-HPLC peptide mapping showed that there was no change in composition and structure after the rhPro-UK stored at -20℃ for 78 months. Conclusion： The shelf life of lyophilized rhPro-UK products kept at 4℃ could reach 3 years, and the lyophilized rhPro-UK was very stable when stored at -20℃.