Jiang Chengcheng, Secundo Francesco, Mao Xiangzhao
College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China.
Key Laboratory for Biological Processing of Aquatic Products, China National Light Industry, Qingdao, 266237 China.
Mar Life Sci Technol. 2023 Jul 12;5(3):387-399. doi: 10.1007/s42995-023-00181-2. eCollection 2023 Aug.
Carrageenan oligosaccharides are important products that have demonstrated numerous bioactivities useful in the food, medicine, and cosmetics industries. However, the specific structure-function relationships of carrageenan oligosaccharides are not clearly described due to the deficiency of high specific carrageenases. Here, a truncated mutant OUC-FaKC16Q based on the reported -neocarratetrose (N4)-producing -carrageenase OUC-FaKC16A from was constructed and further studied. After truncating the C-terminal Por_Secre_tail (PorS) domain (responsible for substrate binding), the catalytic efficiency and temperature stability decreased to a certain extent. Surprisingly, this truncation also enabled OUC-FaKC16Q to hydrolyze N4 into -neocarrabiose (N2). The offset of Arg residue in OUC-FaKC16Q may explain this change. Moreover, the high catalytic abilities, the main products, and the degradation modes of OUC-FaKC16A and OUC-FaKC16Q toward furcellaran were also demonstrated. Data suggested OUC-FaKC16A and OUC-FaKC16Q could hydrolyze furcellaran to produce mainly the desulfated oligosaccharides DA-G-(DA-G4S) and DA-G-DA-G4S, respectively. As a result, the spectrum of products of -carrageenase OUC-FaKC16A has been fully expanded in this study, indicating its promising potential for application in the biomanufacturing of carrageenan oligosaccharides with specific structures.
The online version contains supplementary material available at 10.1007/s42995-023-00181-2.
卡拉胶寡糖是重要的产品，已证明在食品、医药和化妆品行业具有多种生物活性。然而，由于缺乏高特异性的卡拉胶酶，卡拉胶寡糖的具体结构-功能关系尚未得到清晰描述。在此，基于已报道的来自[具体来源未提及]的产生新卡拉四糖（N4）的κ-卡拉胶酶OUC-FaKC16A构建了截短突变体OUC-FaKC16Q并进行了进一步研究。截短C末端的Por_Secre_tail（PorS）结构域（负责底物结合）后，催化效率和温度稳定性在一定程度上有所下降。令人惊讶的是，这种截短还使OUC-FaKC16Q能够将N4水解为新卡拉二糖（N2）。OUC-FaKC16Q中精氨酸残基的偏移可能解释了这一变化。此外，还展示了OUC-FaKC16A和OUC-FaKC16Q对红藻多糖的高催化能力、主要产物和降解模式。数据表明，OUC-FaKC16A和OUC-FaKC16Q可分别水解红藻多糖，主要产生脱硫酸化寡糖DA-G-(DA-G4S)和DA-G-DA-G4S。因此，本研究中κ-卡拉胶酶OUC-FaKC16A的产物谱得到了充分扩展，表明其在生物制造具有特定结构的卡拉胶寡糖方面具有广阔的应用潜力。
在线版本包含可在10.1007/s42995-023-00181-2获取的补充材料。
