鼠疫菌纤溶酶原激活因子的分离纯化

目的 建立从人工培养的鼠疫菌中分离和纯化纤溶酶原激活因子(Plasminogen activator,Pla)的方法.方法 分别用超声破碎、尿素提取与硫酸铵盐析相结合的方法(简称超声法、尿素法)提取Pla,并分别用离子交换、凝胶过滤两步层析相结合的高效液相色谱和制备电泳纯化Pla,对提取、纯化的Pla进行纤溶酶原激活剂活性检测.结果 鼠疫菌超声破碎上清50%～60%饱和硫酸铵沉淀和尿素浸渍菌粉上清0～10%饱和硫酸铵沉淀,均获得了3条蛋白带相对分子质量(Mr)约31×103、35×103、37×103].纤溶酶原激活剂活性检测两种方法获得蛋白的溶圈直径分别为6.5、7.2 mm.用高效液相色谱纯化的Pla主要由Mr约31×103、35×1033、37×103的3条蛋白带组成,纤溶酶原激活剂活性检测溶圈直径为5.0 mm.制备电泳纯化的Pla主要由Mr约31×103、35×103、37×103的3条蛋白带组成.条带所在位置还有其他一些低浓度蛋白存在,纤溶酶原激活剂活性检测无溶圈出现.结论 超声法和尿素法可以提取到Pla,后者经高效液相色谱和制备电泳可以达到基本纯化.

Isolation and purification of plasminogen activator of Yersinia pestis

Objective To find methods to isolate and purify plasminogen activator (Pla) from artificial culture of Yersinia pestis. Methods Ultrasonication and urea extracting combined by ammonium sulfate salting-out were tried to extract Pla. High performance liquid chromatography(HPLC) was used to purify Pla. The first step was ion exchange and the second was gel filtration, Preparative electrophoresis was used to purify Pla, too. The enzyme activity of the isolated or purificated Pla was detected. Results Both 50% - 60% saturated ammonium sulfate deposition of supernatant of plague bacilli ultrasonication and 0 - 10% saturated ammonium sulfate deposition of supernatant of plague bacilli powder soaked by urea had three bands(Mr about 31×103, 35×103 and 37×103) and lysis rings were 6.5 and 7.2 mm in diameter respectively when the enzyme activity was detected. Pla purified by HPLC was mainly composed of three bands(Mr about 31×103, 35×103 and 37×103), occupying more than 80% of total protein weight and lysis ring was 5.0 mm in diameter. Pla purified by preparative electrophoresis mainly consisted of three bands(Mr about 31×103, 35×103 and 37×103) with other proteins of low concentration nearby, no lysis ring was detected. Conclusions Pla is collected by the methods of ultrasonication and urea extracting. Priliminary purification of Pla can be achieved by HPLC and preparative electrophoresis.