College of Basic Medicine, Qingdao University, Qingdao, China; Molecular Cancer Biology Laboratory, Cellular Heterogeneity Research Center, Department of Biosystem, Sookmyung Women's University, Seoul, South Korea.
College of Basic Medicine, Qingdao University, Qingdao, China.
Food Chem. 2021 Mar 1;339:128027. doi: 10.1016/j.foodchem.2020.128027. Epub 2020 Sep 8.
κ-Carrageenase cleaves the β-(1-4) linkages of κ-carrageenan into κ-carrageenan oligosaccharides (κ-COS), which exhibit various biological activities. In this study, a glycoside hydrolase (GH) family 16 κ-carrageenase gene, cgkA, was cloned from the marine bacterium Vibrio sp. SY01 and secretory expressed in a food-grade host, Yarrowia lipolytica. The specific activity of the purified CgkA was 12.5 U/mg. Determination of biochemical properties showed that CgkA was a thermo-tolerant enzyme, and 59.9% of the initial enzyme activity was recovered by immediately placing the sample at 20 °C for 30 min after enzymatic inactivation by boiling for 5 min. The recombinant CgkA was an endo-type enzyme, the main enzymatic product was κ-carradiaose (accounting for 87.6% of total products), and κ-carratetraose was the minimum substrate. Additionally, in vitro and in vivo analyses indicated that enzymatic κ-carradiaose possesses anti-oxidant activity. These features make CgkA as a promising candidate for biotechnological applications in the production of anti-oxidant κ-COS.
κ-卡拉胶酶将κ-卡拉胶的β-(1-4)键断裂成κ-卡拉胶低聚糖（κ-COS），其具有多种生物活性。本研究从海洋细菌 Vibrio sp. SY01 中克隆了一种糖苷水解酶（GH）家族 16 κ-卡拉胶酶基因 cgkA，并在食品级宿主解脂耶氏酵母中进行了分泌表达。纯化的 CgkA 的比活为 12.5 U/mg。生化性质测定表明，CgkA 是一种耐热酶，在酶失活后立即煮沸 5 分钟，然后在 20°C 下放置 30 分钟，可回收 59.9%的初始酶活性。重组 CgkA 是一种内切酶，主要的酶解产物是 κ-卡拉二糖（占总产物的 87.6%），κ-卡拉四糖是最小的底物。此外，体外和体内分析表明，酶解 κ-卡拉二糖具有抗氧化活性。这些特性使 CgkA 成为生产抗氧化 κ-COS 的生物技术应用中有前途的候选者。
