食品科学 ›› 2013, Vol. 34 ›› Issue (5): 161-166.doi: 10.7506/spkx1002-6630-201305034

• 生物工程 • 上一篇    下一篇

新型生物防腐剂——多聚阳离子抗菌肽在毕赤酵母中的表达

李 青,周晓宏*   

  1. 北京理工大学生命学院,北京 100081
  • 收稿日期:2011-11-17 修回日期:2013-01-25 出版日期:2013-03-15 发布日期:2013-04-16
  • 通讯作者: 周晓宏 E-mail:zhouxh@bit.edu.cn
  • 基金资助:
    “十二五”国家科技支撑计划项目“食品添加剂制造关键技术研究”;“十二五”国家科技支撑计划项目“1万吨/年富含蛋白质发酵残渣高值化利用技术及示范”

Expression of a Novel Poly-Cationic Antibacterial Peptide as a Food Preservative in Genetically Engineered Pichia pastoris

LI Qing,ZHOU Xiao-hong*   

  1. School of Life Science, Beijing Institute of Technology, Beijing 100081, China
  • Received:2011-11-17 Revised:2013-01-25 Online:2013-03-15 Published:2013-04-16
  • Contact: Xiao-Hong ZHOU E-mail:zhouxh@bit.edu.cn

摘要: 在毕赤酵母GS115中表达一种新型食品生物防腐剂——多聚阳离子抗菌肽(poly-cationic antibacterialpeptide,PCAP)。根据毕赤酵母密码子的偏爱性,人工合成编码多聚阳离子抗菌肽与多聚阴离子肽融合肽的DNA序列,连接并克隆入酵母表达载体pPIC9,得到重组表达质粒pPIC9-PCAP,并转化至毕赤酵母GS115,筛选阳性克隆子,用体积分数0.5%的甲醇诱导表达,优化表达条件,表达产物用Tricine-SDS-PAGE分析,在分子质量8kD左右处可见目的蛋白表达条带,表明融合肽成功地在毕赤酵母中分泌表达。在pH2.0条件下将表达产物采用胃蛋白酶酶解,分离得到的碱性多聚阳离子肽对食品腐败微生物枯草芽孢杆菌具有明显的抑菌作用。

关键词: 多聚阳离子, 抗菌肽, 毕赤酵母, 防腐剂

Abstract: A novel polycationic antibacterial peptide (PCAP) as a food preservative was expressed in genetically engineered Pichia pastoris. A fusion peptide gene of a polycationic and polyanionic peptide was synthesized according to the codon of Pichia pastoris, and then cloned into the vector pPIC9.The constructed recombinant plasmid pPIC9-PCAP was transformed into Pichia pastoris GS115, and the positive clones were screened on histidine-deficient MD medium and was then expressed under induction by 0.5% methanol in BMMY medium. The expressed fusion peptide was identified as a peptide with molecular weight of 8 kD in Tricine-SDS-PAGE, and then digested with pepsin at pH2.0 The polycationic peptide was separated and proved to have antibacterial activity against food spoilage microorganism Bacillus subtilis.

Key words: polycationic, antibacterial peptide, Pichia pastoris, preservative

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