生物技术通报 ›› 2018, Vol. 34 ›› Issue (10): 135-142.doi: 10.13560/j.cnki.biotech.bull.1985.2018-0241

• 研究报告 • 上一篇    下一篇

三疣梭子蟹C型溶菌酶在毕赤酵母中的表达及其抑菌活性

王强厚, 陶妍, 崔旭, 颜倩倩, 张亚莉   

  1. 上海海洋大学食品学院 上海水产品加工及贮藏工程技术研究中心,上海 201306
  • 收稿日期:2018-03-19 出版日期:2018-10-26 发布日期:2018-11-07
  • 作者简介:王强厚,男,硕士研究生,研究方向:甲壳动物抗菌肽的基因工程制备;E-mail:297272796@qq.com
  • 基金资助:

    上海市科委工程中心能力提升项目(16DZ2280300)

Expression of Swimming Crab C-type Lysozyme in Pichia pastoris and Its Bacteriostatic Activity

WANG Qiang-hou, TAO Yan, CUI Xu, YAN Qian-qian, ZHANG Ya-li   

  1. Shanghai Engineering Research Center of Aquatic-Processing & Preservation,College of Food Science and Technology,Shanghai Ocean University,Shanghai 201306
  • Received:2018-03-19 Published:2018-10-26 Online:2018-11-07

摘要:

C型溶菌酶是存在于各种生物组织中的重要的先天性免疫蛋白,是开发天然抑菌剂的良好候选者。以甲壳类动物三疣梭子蟹(Portunus trituberculatus)C型溶菌酶成熟肽为研究对象,首先通过RT-PCR克隆其编码基因“ptlyC”;以pPICZαA为表达载体,构建重组表达载体pPICZαA-ptlyC,电转至毕赤酵母(Pichia pastoris)X-33后,通过高浓度的博来霉素筛选到高拷贝酵母转化子;在28℃、250 r/min和pH6.0的条件下,经1%的甲醇诱导表达72 h,得到含重组ptlyC的培养液上清;经固化金属离子亲和层析(IMAC)纯化,得到分子量约为25.3 kD的纯化产物。通过菌落计数法证明含重组ptlyC的培养液上清具有抑制革兰氏阳性的枯草芽孢杆菌(Bacillus subtilis)的活性;通过琼脂糖凝胶扩散法证明纯化的重组ptlyC具有抑制革兰氏阴性的铜绿假单胞菌(Pseudomonas aeruginosa)、副溶血性弧菌(Vibrio parahaemolyticus)和沙门氏菌(Salmonella lignieres)的活性。

关键词: 三疣梭子蟹, C型溶菌酶, 毕赤酵母, 重组DNA表达, 抑菌活性

Abstract:

C-type lysozyme is an innate immune protein existing in different tissues of all organisms,thus it is a favorable candidate for developing natural bacteriostatic agent. In this study,mature peptide of C-type lysozyme from crustacean swimming crab(Portunus trituberculatus)was the object of recombinant DNA expression. Firstly,cDNA fragment encoding the C-type lysozyme mature peptide was cloned by RT-PCR,and was named as “ptlyC”. The ptlyC was ligated to pPICZαA vector to construct recombinant expression vector pPICZαA-ptlyC;then the pPICZαA-ptlyC was transformed into competent Pichia pastoris X-33 cells. Yeast transformants containing multi-copy gene insertion were screened by high concentration of zeocin. Recombinant ptlyC was induced with 1.0%(V/V)methanol at 28℃,250 r/min and pH6.0 for 72 h. The culture medium supernatant containing recombinant ptlyC was subjected to immobilized metal affinity chromatography(IMAC)for purification,and the molecular mass of the purified ptlyC was about 25.3 kD. Micro liquid-bacterial colony notation demonstrated that the culture medium supernatant containing recombinant ptlyC had a bacteriostatic effect on gram-positive Bacillus subtilis. Further,agar well diffusion assays confirmed that the purified recombinant ptlyC inhibited gram-negative Pseudomonas aeruginosa,Vibrio parahaemolyticus and Salmonella lignieres.

Key words: Protunus trituberculatus, C-type lysozyme, Pichia pastoris, recombinant DNA expression, bacteriostatic activity