The stability improvement of dextransucrase by artificial extension modification of the V domain of the enzyme

• Published in: Enzyme and microbial technology 2021-11, Vol.151, p.109919-109919, Article 109919
• Main Authors: Zhang, Yu-xin, Yang, Jing-wen, Wu, Yuan-yuan, Hu, Xue-qin, Zhang, Hong-bin
• Format: Article
• Language: English
• Subjects: C-terminus; dextran; Dextransucrase; domain modification; stability
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2021.109919

•The variant D-F was identified from a series of dextransucrase variants and showed significantly stability.•Appropriate domain extension might be a possible reason for stability.•Changing the final amount of enzyme activity of D-F can adjust the molecular weight of the product range.•It has a great research value to the stability of dextransucrase. Improving enzyme stability is very important for enzyme applications. Structural modification is a reliable and effective method to improve the characteristics of protein. By artificially extending the C-terminus, 6 domain modification variants of different sizes were constructed, and a new enzyme species with high stability was obtained. Experimental results affirmed that high stability can be achieved by decreasing the degree of domain freedom. The optimum temperatures of domain modification variants were improved by 10 °C compared with the original enzyme. Specifically, compared with the original enzyme, the half-life of the variant dexYG-fdx (D-F) was increased to 280% under 35 °C and 200% under 45 °C, and the pH tolerance range was wider. Further structural simulations and molecular docking studies provided a reasonable explanation (The increased domain reduced the degree of freedom of the enzyme terminal to some extent) for this variant to increase stability and produce dextran. This study can provide valuable information for increasing the characteristics of recombinant dextransucrase.