Improving the Catalytic Activity and Thermostability of MAS1 Lipase by Alanine Substitution
Improving the Catalytic Activity and Thermostability of MAS1 Lipase by Alanine Substitution
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通过丙氨酸取代提高 MAS1 脂肪酶的催化活性和热稳定性
DOI：
10.1007/s12033-018-0062-y
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发表时间：
2018
影响因子：
2.6
通讯作者：
Wang YH
中科院分区：
文献类型：
--
作者：
Zhao Ge;Tang Qingyun;Lan Dongming;Wang Yonghua;Wang Jianrong;Lan DM;Wang YH
MAS 1是从链霉菌中分离的脂肪酶。菌株W 007在生物技术中具有潜在应用。MAS 1脂肪酶的结构分析表明，位于底物结合口袋中的8个大侧氨基酸可能参与影响催化性能。进行这些残基的丙氨酸取代以减少催化口袋的空间冲突并探测其功能作用。突变体H108 A、F153 A和V233 A的kcat/Km分别增加到2.3倍、2.1倍和1.4倍。有趣的是，F153 A的半衰期（60 °C）在诱变后已经转移到523分钟，这是MAS 1野生型的五倍增强。突变体H108 A和F153 A对高熔点棕榈硬脂的水解能力较强，在油脂改性中具有潜在的应用价值。本工作为利用蛋白质工程技术获得具有理想催化性能的生物催化剂提供了一个范例。
MAS1 is a lipase isolated fromStreptomycessp. strain W007 with potential application in biotechnology. Structural analysis of MAS1 lipase showed that eight amino acids with bulkier side located in the substrate-binding pocket may be involved in affecting catalytic performance. Alanine substitutions of those residues were conducted to reduce steric clash of catalyzed pocket and probe their functional roles. Thekcat/Kmof mutants H108A, F153A, and V233A increased to 2.3-, 2.1-, and 1.4-fold, respectively. Interestingly, the half-life (60 °C) of F153A had shifted to 523 min after mutagenesis, which was fivefold enhancement toward that of MAS1 wide-type. Furthermore, higher hydrolysis ability of mutants H108A and F153A toward palm stearin of high melting temperature made them potentially applicable in oil/fat modification. Our work provided an example to obtain biocatalysts with desired catalytic behaviors by protein engineering.