Elucidation of a Unique Pattern and the Role of Carbohydrate Binding Module of an Alginate Lyase
Elucidation of a Unique Pattern and the Role of Carbohydrate Binding Module of an Alginate Lyase
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阐明藻酸盐裂解酶的独特模式和碳水化合物结合模块的作用
DOI：
10.3390/md18010032
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发表时间：
2020-01-01
期刊：
影响因子：
5.4
通讯作者：
Ming, Dengming
中科院分区：
文献类型：
--
作者：
Hu, Fu;Zhu, Benwei;Ming, Dengming
不同聚合度的海藻酸低聚糖具有不同的生理活性。因此，近年来，利用酶来制备食品和工业用藻酸低聚糖的研究越来越受到重视。此前，我们鉴定并鉴定了一种新的双功能海藻酸裂解酶Aly7A，它可以从三种不同的底物类型中特异地释放三糖，具有独特的降解模式。在这里，我们通过模块截断和分子对接的方法研究了其降解模式。结果表明，Aly7A对不同的底物采取了独特的作用方式，底物链滑入催化结构域的结合口袋，定位下一个三糖进行切割。Aly7A糖结合模块(CBM)结构域的缺失导致降解产物分布复杂，不利于三糖的形成，表明CBM可能在三糖释放过程中起到“控制者”的作用。这项研究进一步证明了煤层气是产品分布的调节器，并为明确定义的藻酸盐低聚糖与相关的煤层气的生成提供了新的见解。
Alginate oligosaccharides with different degrees of polymerization (DPs) possess diverse physiological activities. Therefore, in recent years, increasing attention has been drawn to the use of enzymes for the preparation of alginate oligosaccharides for food and industrial applications. Previously, we identified and characterized a novel bifunctional alginate lyase Aly7A, which can specifically release trisaccharide from three different substrate types with a unique degradation pattern. Herein, we investigated its degradation pattern by modular truncation and molecular docking. The results suggested that Aly7A adopted a unique action mode towards different substrates with the substrate chain sliding into the binding pocket of the catalytic domain to position the next trisaccharide for cleavage. Deletion of the Aly7A carbohydrate binding module (CBM) domain resulted in a complex distribution of degradation products and no preference for trisaccharide formation, indicating that the CBM may act as a “controller” during the trisaccharide release process. This study further testifies CBM as a regulator of product distribution and provides new insights into well-defined generation of alginate oligosaccharides with associated CBMs.