Department of Food Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea; Department of Food Technology, An Giang University, An Giang 880000, Viet Nam; Vietnam National University, Ho Chi Minh City 700000, Viet Nam.
Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea; Division of Animal, Horticultural and Food Sciences, Graduate School of Chungbuk National University, Cheongju, 28644, Chungbuk, Republic of Korea.
Carbohydr Polym. 2022 May 15;284:119175. doi: 10.1016/j.carbpol.2022.119175. Epub 2022 Jan 25.
The one-step synthesis of glycogen-type polysaccharides from maltooctaose (G8) was accomplished based on the new findings of the catalytic mechanism of glycogen branching enzymes (GBEs) from Vibrio vulnificus, Deinococcus geothermalis, and Escherichia coli. GBEs from D. geothermalis and E. coli used maltononaose and maltotridecaose as the minimum, respectively, while V. vulnificus GBE (VvGBE) catalyzed the surprisingly small substrate, G8, into polysaccharides. Intriguingly, all three GBEs catalyzed α-1,4-transglycosylation at the early reaction stage of transglycosylation. VvGBE successfully converted the smallest substrate (G8) into two highly branched polysaccharides (HBP), in which the big polysaccharide (1.49 × 10 Da) exhibited structural properties similar to glycogen. Both HBPs had similar side chain distribution with a very short average degree of polymerization compared with mussel glycogen. As a molecular biology reagent, these nucleotide-free HBPs significantly increased the mRNA extraction efficiency of mammalian cells. Our results provide a new approach to the synthesis of novel polysaccharides.
一步法合成糖原型多糖从麦芽八糖（G8）是基于糖原分支酶（GBE）的催化机制的新发现，来自创伤弧菌、地热能球菌和大肠杆菌。来自 D. geothermalis 和 E. coli 的 GBE 分别以麦芽七糖和麦芽三糖作为最小底物，而 V. vulnificus GBE（VvGBE）则将惊人的小底物 G8 催化成多糖。有趣的是，三种 GBE 在转糖基化的早期反应阶段都催化了α-1,4-转糖基化。VvGBE 成功地将最小的底物（G8）转化为两种高度支化的多糖（HBP），其中大多糖（1.49×10 Da）表现出与糖原相似的结构特性。两种 HBP 的侧链分布相似，与贻贝糖原相比，其平均聚合度非常短。作为分子生物学试剂，这些无核苷酸的 HBP 显著提高了哺乳动物细胞的 mRNA 提取效率。我们的结果为新型多糖的合成提供了一种新方法。
