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。 To study the chemical modification and purification of L-asparaginase monomethoxy polyethylene glycol. The yield of single modification of the product was analyzed by SDS-PAGE. The molar ratio of the reaction, the pH value of the reaction and the reaction time and temperature were optimized. The optimal modification conditions were L-ASP and mPEG. The molar ratio of ALD was 1:10, reaction pH 5.0, reaction at 4 ℃ for 32 h. The products were separated and purified by ion exchange and molecular sieve. The residues of modified products reached 36%. The structure of the modified product did not change significantly, and the activity was well preserved.