pTYB11载体的应用及其重组子破菌条件的研究

IMPACTTM—CN蛋白质纯化系统的pTYB11载体的应用,有利于快速分离靶蛋白。因靶蛋白位于胞内,需采取有效破碎手段获取。采用超声波破碎,试验找出重组大肠杆菌的最佳破碎条件为:超声时间占空比为3:7,输出功率40W,破碎0.5h。western-blotting检验可以得到抗原性正常的靶蛋白。

非融合型重组人白细胞介素-18的纯化及鉴定

目的 获得高纯度的重组人白细胞介素 18(rhIL 18)。方法 采用溶菌酶加超声破菌的方法抽提包涵体 ,以8mol/L尿素溶解包涵体 ,变性条件下以阴离子柱层析进行首步纯化 ,复性后再进行凝胶过滤层析。对纯化的样品进行了SDS PAGE、HPLC、N端氨基酸序列、免疫印迹及生物学活性分析。结果 rhIL 18在大肠杆菌中以不溶性包涵体形式存在 ,所提取的包涵体中重组蛋白纯度可达到 80 %以上 ,包涵体经二步柱层析纯化后 ,HPLC分析纯度达 98%以上 ,SDS PAGE测定其分子质量约 19× 10 3 ,N端 15个氨基酸序列与预期一致 ,生物学活性分析证实纯化的rhIL 18具有诱导人外周血单个核细胞 (PBMC)产生IFN γ的能力。结论 所建立的纯化rhIL 18的方法简便有效 ,为开展rhIL 18的结构活性关系研究及其大规模纯化打下了良好的基础。

Influence of Ultrasonic on Broken Effect of Foodborne Polluting Strains

[ Objective] The aim was to study on influence of ultrasonic on broken effect of foodborne polluting strains. [Method ] Escherichia coli, Staphylococcus aureus, and Aspergillus niger in different concentrations were tested in different ultrasonic powers and times for the broken effects.[ Result ] Eschedchia coil and Staphylococcus aureus were more sensitive to ultrasonication and the broken rates were as high as 96%. Aspergillus niger, however, was not so sensitive and the broken rate was only about 40%. The optimum parameters, including ultrasonic power, ultrasonic time and OD, of Escherichia coli were 600 W, 14 rain and 0.997, of Staphylococcus aureus were 600 W, 15 min and 1.440, and of Aspergillus ni- ger were 700 W, 20 min and 0.893, respectively. [ Conclusion] The research provided references for application of ultrasonic technology in food sterilization.