食品科学 ›› 2022, Vol. 43 ›› Issue (22): 159-165.doi: 10.7506/spkx1002-6630-20211129-358

• 生物工程 • 上一篇    

基于理性设计提高假交替单胞菌κ-卡拉胶酶热稳定性

龙柳妃,苏羽,陈艳红,姜泽东,倪辉,李清彪,朱艳冰   

  1. (1.集美大学海洋食品与生物工程学院,福建 厦门 361021;2.福建省食品微生物与酶工程重点实验室,厦门市食品生物工程技术研究中心,福建 厦门 361021)
  • 发布日期:2022-12-12
  • 基金资助:
    福建省自然科学基金项目(2020J01679);国家自然科学基金面上项目(41976124); 福建省科技重大专项(2020NZ012015)

Thermostability Improvement of κ-Carrageenase from Pseudoalteromonas sp. by Rational Design

LONG Liufei, SU Yu, CHEN Yanhong, JIANG Zedong, NI Hui, LI Qingbiao, ZHU Yanbing   

  1. (1. College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China;2. Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China)
  • Published:2022-12-12

摘要: 对假交替单胞菌JMUZ2的κ-卡拉胶酶进行理性设计,以获得热稳定性提高的突变酶。用PoPMuSiC在线分析工具对假交替单胞菌κ-卡拉胶酶进行分析,筛选了10 个单点突变体。利用定点突变获得突变酶基因,并对突变酶进行诱导表达、纯化及性质鉴定,筛选出酶比活力不降低且热稳定性提高的突变体K155A。热稳定性分析表明,在50、55 ℃和60 ℃分别处理40 min,突变酶残余酶活力分别是野生型酶的1.8、2.7 倍和4.5 倍。酶的结构及分子动力学模拟分析表明,酶分子疏水相互作用和结构刚性的增强是K155A突变体热稳定性提高的可能原因。通过理性设计获得假交替单胞菌κ-卡拉胶酶热稳定性提高的突变体K155A,对改善酶的性质、扩大κ-卡拉胶酶的应用范围以及κ-卡拉胶酶结构与功能关系研究具有重要意义。

关键词: κ-卡拉胶酶;热稳定性;理性设计

Abstract: This study aimed to improve the thermostability of κ-carrageenase from Pseudoalteromonas sp. JMUZ2 by rational design. A total of 10 single-site mutants were chosen using the PoPMuSiC program to analyze the sequence of the κ-carrageenase gene. A mutant gene was obtained by site-directed mutagenesis. The mutant enzyme was expressed under induced conditions, purified and identified. The mutant K155A could maintain the specific enzyme activity and had improved thermostability. After treatment at 50, 55, and 60 ℃ for 40 min, the thermal stability of the mutant K155A was 1.8, 2.7, and 4.5 times higher than that of the wild-type enzyme (WT), respectively. The structure and molecular dynamic simulation analysis showed that the increase in hydrophobic interactions and structural rigidity may be the cause of the improved thermal stability of K155A. This study is of great significance for improving the properties of κ-carrageenase, expanding its application scope, and studying its structural-functional relationship.

Key words: κ-carrageenase; thermostability; rational design

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