聚乙二醇醛(mPEG-ALD_(20000))对L-门冬酰胺酶化学修饰的初步研究

Primary Study on the Modification of L-ASP with mPEG-ALD_(20000)

研究L-门冬酰胺酶的单甲氧基聚乙二醇醛化学修饰及纯化方法。以SDS-PAGE分析产物的单修饰产率,对反应的摩尔比,反应的pH值和反应时间和温度修饰条件进行优化,初步确定最佳修饰条件为L-ASP与mPEG、ALD反应摩尔比是1∶10,反应pH值为5.0,在4℃下反应32 h。离子交换和分子筛联用对产物进行分离纯化,修饰产物活性残留达36%。修饰产物结构没有明显变化,活性得到很好的保留。

L-asparaginase （L-ASP） modified with succinimidehyde monomethoxy polyethylene glycol （mPEG-ALD） and its purification was studied. The modification rate of mono-PEGylated enzyme by SDS-PAGE was analyzed and the modified conditions, such as molecular ratio, pH value, reaction tem- perature and time were optimized. The optimized reaction conditions were found to be phosphate buffer pHS. 0,moleeuar ratio of mPEG-ALD to L-ASP 10 ： 1, reaction time 32h and reaction temperature 4℃. The PEGylated enzyme was purified by anion-exchange and gel filtration and its activity retained 360%. The modified PEG-L-ASP with noob change in strueture and its activity has been well reserved.