食品科学

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高山被孢霉Δ5去饱和酶基因的克隆及异源表达研究

刘建民1,2,栗茂腾1,*   

  1. 1.华中科技大学生命科学与技术学院,湖北 武汉 430074;2.河南理工大学资源环境学院,河南 焦作 454000
  • 出版日期:2013-08-15 发布日期:2013-09-03
  • 通讯作者: 栗茂腾
  • 基金资助:

    教育部新世纪优秀人才支持计划项目(NCET110172);国家自然科学基金青年科学基金项目(41202113);
    河南理工大学博士基金项目(B2011-035)

Cloning and Heterologous Expression of Δ5 Desaturase Gene from Mortiella alpina

LIU Jian-min1,2,LI Mao-teng1,*   

  1. 1. College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China;
    2. Institute of Resources and Environment, Henan Polytechnic University, Jiaozuo 454000, China
  • Online:2013-08-15 Published:2013-09-03
  • Contact: LI Mao-teng

摘要:

通过RT-RCR的方法从高山被孢霉W15菌株中扩增到完整的Δ5去饱和酶基因,其全长为1341bp,编码446个氨基酸。对推导的氨基酸序列进行分析表明,其N末端存在细胞色素b5结构域,在序列中还存在3个保守的组氨酸富集区。将该基因连接到表达载体pPIC3.5K上,转化毕赤酵母细胞,利用G418筛选高拷贝数的转化子。以双高γ-亚麻酸为底物,在甲醇诱导的条件下,Δ5去饱和酶可催化底物脱氢生成花生四烯酸,其含量占总脂肪酸含量的2.85%。说明克隆的Δ5去饱和酶基因能在毕赤酵母中进行功能性的表达。

关键词: 高山被孢霉, &Delta, 5去饱和酶基因, 毕赤酵母, 花生四烯酸

Abstract:

Arachidonic acid, an essential fatty acid for humans, plays important physiological functions in the intelligence
development and vision development of infants. In this study, a complete Δ5 desaturase gene was cloned from Mortierella
alpina W15 by RT-PCR amplification. The gene with 1341 bp in length encoded 446 amino acids. The deduced amino acid
sequence demonstrated the cytochrome b5 domain in the N terminal and three conserved histidine boxes in the sequence.
Then the gene was inserted into the expression vector pPIC3.5K and transformed into Pichia pastoris GS115. Transformants
containing multi-copy Δ5 desaturase genes were screened by Geneticin (G418). When dihomo-γ-linolenic acid was provided
as the exogenous substrate to the culture induced by methanol, the dehydrogenation of the substrate was catalyzed by Δ5
desaturase to produce arachidonic acid reaching 2.85% in the total fatty acids. This result indicated that the cloned gene
encoded functional Δ5 desaturase in P. pastoris GS115.

Key words: Mortierella alpina;&Delta, 5 desaturase gene;Pichia pastoris GS115;arachidonic acid

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