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›› 2007, Vol. 27 ›› Issue (3): 289-292.doi: 10.7525/j.issn.1673-5102.2007.03.008

• 论文 • 上一篇    下一篇

发菜中超氧化物歧化酶基因的克隆及在大肠杆菌中的表达

汪 滢;陈李萍;陈 晓;章 秀;于 晶;王全喜*   

  1. 上海师范大学生命与环境科学学院,上海 200234
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2007-05-20 发布日期:2007-05-20
  • 通讯作者: 王全喜

Cloning and Expression of Gene which Encode SOD of Nostoc flagelliforme in E. coli

WANG Ying;CHEN Li-Ping;CHEN Xiao;ZHANG Xiu;YU Jing;WANG Quan-Xi*   

  1. College of Life and Environment Sciences,Shanghai Normal University,Shanghai 200234
  • Received:1900-01-01 Revised:1900-01-01 Online:2007-05-20 Published:2007-05-20
  • Contact: WANG Quan-Xi

摘要: 采用基因工程技术从发菜总DNA中克隆了一段的基因序列,该序列与基因库中已公布的编码地木耳(Nostoc commnue)超氧化物歧化酶的氨基酸序列同源性为97%。将该基因插入含T7启动子质粒pET-32中构建表达质粒pET-sod,然后将该表达质粒转入大肠杆菌BL21中进行蛋白表达,表达菌株用1 mmol·L-1 IPTG诱导表达数小时后,产生较多的重组的蛋白,且该蛋白以可溶性蛋白形式存在。SDS-PAGE分析表明,在相对分子量约为22 kd的位置有一条明显蛋白质带。将诱导表达后的蛋白通过亲和层析的方法进行蛋白纯化;NBT光还原法测定表达产物的比活力,每毫克纯化蛋白约为2 550 U。对纯化后的蛋白进行高温胁迫研究,将该纯化蛋白在60℃高温下胁迫90 min后,其活性为原(未经胁迫)蛋白活性的85%。

关键词: 发菜, 超氧化物岐化酶基因克隆, 诱导表达, 酶活测定

Abstract: SOD gene was cloned from Nostoc flagelliforme and the amino acid sequence is 97% identical to that of Nostoc commune published. The gene was inserted into a constructed E.coli expression plasmid pET-sod and the plasmid was transferred into expressing host BL21. Induced by 1 mmol·L-1 IPTG,the recombinant SOD of Nostoc flagelliforme was accumulated to a very high percent and the protein is exist as soluble protein. SDS-PAGE analysis revealed that the molecular weight of expression SOD of Nostoc flagelliforme was approximate 22 kd. Purified by Ni2+-resin column,the specific enzymatic activity was measured using NBT method and the calculated result of this purified enzyme is 2 550 U·mg-1. It was also found that after high temperature stress at 60℃ for 90 min,the specific enzymatic activity still retains 85%.

Key words: Nostoc flagelliforme, gene cloning of SOD, induced expression, activity measurement of SOD