State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China.
State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China.
Carbohydr Polym. 2024 Nov 1;343:122474. doi: 10.1016/j.carbpol.2024.122474. Epub 2024 Jul 9.
Alginate is one of the most important marine colloidal polysaccharides, and its oligosaccharides have been proven to possess diverse biological functions. Alginate lyases could specifically degrade alginate and therefore serve as desirable tools for the research and development of alginate. In this report, a novel catalytic domain, which demonstrated no significant sequence similarity with all previously defined functional domains, was verified to exhibit a random endo-acting lyase activity to alginate. The action pattern analysis revealed that the heterologously expressed protein, named Aly44A, preferred to degrade polyM. Its minimum substrates and the minimum products were identified as unsaturated alginate trisaccharides and disaccharides, respectively. Based on the sequence novelty of Aly44A and its homologs, a new polysaccharide lyase family (PL44) was proposed. The discovery of the novel enzyme and polysaccharide lyase family provided a new entrance for the gene-mining and acquiring of alginate lyases, and would facilitate to the utilization of alginate and its oligosaccharides.
海藻酸盐是最重要的海洋胶体多糖之一，其寡糖已被证明具有多种生物功能。海藻酸盐裂解酶可以特异性地降解海藻酸盐，因此是研究和开发海藻酸盐的理想工具。在本报告中，鉴定出一种新型催化结构域，该结构域与所有先前定义的功能结构域均无明显的序列相似性，表现出随机内切裂解酶活性。作用模式分析表明，异源表达的蛋白，命名为 Aly44A，优先降解聚 M。其最小底物和最小产物分别鉴定为不饱和海藻酸盐三糖和二糖。基于 Aly44A 及其同源物的序列新颖性，提出了一个新的多糖裂解酶家族（PL44）。新型酶和多糖裂解酶家族的发现为基因挖掘和获取海藻酸盐裂解酶提供了一个新的途径，并将有助于海藻酸盐及其寡糖的利用。
