准噶尔小胸鳖甲抗冻蛋白MPAFP5毕赤酵母表达产物的理化性质  

Characterization of antifreeze protein MPAFP5 from Microdera punctipennis dzhungarica expressed in Pichia pastoris

作　　者：吕国栋[1] 孙洁[1] 马纪[1] 张富春[1] 

机构地区：[1]新疆大学生命科学与技术学院分子生物学重点实验室

出　　处：《昆虫知识》2006年第6期821-826,共6页Entomological Knowledge

基　　金：科技部重大基础研究前期研究专项(2003CCA01000);新疆生物资源基因工程重点实验室开放课题(XJDX0201-200403)

摘　　要：研究准噶尔小胸鳖甲Microdera punctipennis dzhungarica Kasz抗冻蛋白MPAFP5真核表达产物的功能及理化性质。首先用硫酸铵浓度梯度沉淀初步纯化酵母真核表达产物,然后通过细菌低温保护实验检测抗冻蛋白MPAFP5低温保护功能,同时探讨抗冻蛋白MPAFP5在酸碱环境和100℃时的稳定性,并通过等电聚焦凝胶电泳检测其等电点。研究表明MPAFP5真核表达产物在低温下能够提高细菌的存活率,能够耐受高温和一定程度的强酸强碱,其等电点约为5.8左右。准噶尔小胸鳖甲抗冻蛋白MPAFP5真核表达产物与赤翅甲抗冻蛋白(DAFP)的比较表明拟步甲类昆虫抗冻蛋白具有相似的理化性质。In order to test the function and the physical-chemical properties of the eukaryotic products of antifreeze protein gene mpafp5 cloned from Microdera punctipennis dzhungarica Kasz, the isoelectric point of MPAFP5 was determined by MINI-IEF. The eukaryotic products of MPAFP5 with biological activity can improve the survival rate of the bacterial at low temperature; it was detected by bacterial cryoprotective experiment. In addition, the biological activity of MPAFPS, after treated in acid, alkali and boiled at 100℃ respectively, was checked. The results show that MPAFP5 expressed in yeast has biological activity, and its biological activity is stable in pH 1-12, as well as at 100℃. Its isoelectric focusing point is about 5.8. The physical-chemical properties of eukaryotic expressing products of antifreeze protein gene mpafp5 are similar to that of Dendroides canadensis antifreeze protein （DAFP）.

关 键 词：准噶尔小胸鳖甲 抗冻蛋白 理化性质 等电点 

分 类 号：Q966[生物学—昆虫学]