食品科学 ›› 2011, Vol. 32 ›› Issue (11): 232-238.doi: 10.7506/spkx1002-6630-201111048

• 生物工程 • 上一篇    下一篇

脂肪酶的基因克隆、序列分析、高效表达及其催化特性

张卫国,王小宁,林 影   

  1. 1.韶关学院英东食品科学与工程学院 2.华东理工大学生物工程学院 3.华南理工大学生物科学与工程学院
  • 出版日期:2011-06-15 发布日期:2011-05-13

Cloning and Expression of Lipase Gene in S. cerevisiae and Its Characterization

ZHANG Wei-guo1,2,WANG Xiao-ning3,LIN Ying3,*   

  1. 1. Yingdong College of Food Science and Engineering, Shaoguan University, Shaoguan 512000, China; 2. School of Bioengineering, East China University of Science and Technology, Shanghai 200237, China; 3. School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510641, China
  • Online:2011-06-15 Published:2011-05-13

摘要: 分别以R. miehei 3.4960基因组和总RNA为模板,通过PCR和RT-PCR扩增得到脂肪酶全长基因和脂肪酶cDNA碱基序列,两碱基序列测序结果比对表明:脂肪酶DNA碱基序列由5个内含子和6个外显子组成,5个内含子大小分别为75、58、64、73、59bp,位于DNA序列(以起始密码子ATG的碱基A为1)的600~674位、929~986位、1076~1139位、1227~1299位、1382~1440位碱基处。脂肪酶RML mRNA碱基序列与已公布的R. miehei脂肪酶基因mRNA(EMBL Nucleotide Sequence Database Accession No. A02536)碱基序列有5个碱基的差异,其编码的氨基酸序列有1个发生了改变。利用酿酒酵母表达质粒pICAS1,实现了脂肪酶RML基因在酿酒酵母中的高效分泌表达,并对重组脂肪酶RML进行了相关酶学性质分析。酶学性质研究表明:重组酶的最适反应温度为45℃,最适pH值为8.6;该酶偏爱中链长的酯(C8~C12),对12个碳的酯具有最佳活性,对C16长链酯也有较高的活性,对短链酯的活性较弱;金属离子Cu2+、Fe2+对酶活性有显著抑制作用,Ca2+和Mg2+对酶活有部激活作用。

关键词: 脂肪酶, 基因克隆, 高效表达

Abstract: Two lipase nucleotide sequences were cloned from DNA and total RNA of R. miehei 3.4960 by PCR and RT-PCR, respectively. The sequencing results showed that the nucleotide sequence from the DNA of R. miehei 3.4960 was composed of five introns and six extrons. The lengths of five introns were 75, 58, 64, 73 bp and 59 bp, which were located at the 600-674, 929-986, 1076-1139, 1227-1299 and 1382-1440 sites of nucleotide sequence, respectively. There were five-site mutations between the nucleotide sequence from total RNA of R. miehei 3.4960 and mRNA (EMBL Accession No. A02536) from R. miehei, which could result in one amino acid substitution. The RML gene was successfully expressed in S. cerevisiae MT8-1. The characteristics of RML showed that its optimal temperature and pH were 45 ℃ and 8.6, respectively. RML activity was inhibited by Cu2+ and Fe2+, and activated by Ca2+ and Mg2+. The RML activity was higher for substrates with long chains, especially a substrate with a chain length of C12, but it was very low for substrates with short chains.

Key words: lipase, gene cloning, expression, catalytic characterization

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