Functional Characterization of Carbohydrate-Binding Modules in a New Alginate Lyase, TsAly7B, from Thalassomonas sp. LD5

Marine Drugs

Zhigang Liu¹  Luyao Tang¹  Zhelun Zhang¹  Wengong Yu¹  Mengmeng Bao¹  Feng Han¹ 

[1] Key Laboratory of Marine Drugs (Ministry of Education), Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China;

关键词: alginate lyase;    carbohydrate-binding module;    enzymatic characterization;    thermostability;    enzymatic activity;    product distribution;    polysaccharide lyase;    brown algae;   

DOI  :  10.3390/md18010025

来源: DOAJ

【 摘 要 】

Alginate lyases degrade alginate into oligosaccharides, of which the biological activities have vital roles in various fields. Some alginate lyases contain one or more carbohydrate-binding modules (CBMs), which assist the function of the catalytic modules. However, the precise function of CBMs in alginate lyases has yet to be fully elucidated. We have identified a new multi-domain alginate lyase, TsAly7B, in the marine bacterium Thalassomonas sp. LD5. This novel lyase contains an N-terminal CBM9, an internal CBM32, and a C-terminal polysaccharide lyase family 7 (PL7) catalytic module. To investigate the specific function of each of these CBMs, we expressed and characterized the full-length TsAly7B and three truncated mutants: TM1 (CBM32-PL7), TM2 (CBM9-PL7), and TM3 (PL7 catalytic module). CBM9 and CBM32 could enhance the degradation of alginate. Notably, the specific activity of TM2 was 7.6-fold higher than that of TM3. CBM32 enhanced the resistance of the catalytic module to high temperatures. In addition, a combination of CBM9 and CBM32 showed enhanced thermostability when incubated at 80 °C for 1 h. This is the first report that finds CBM9 can significantly improve the ability of enzyme degradation. Our findings provide new insight into the interrelationships of tandem CBMs and alginate lyases and other polysaccharide-degrading enzymes, which may inspire CBM fusion strategies.

【 授权许可】

Unknown