纤维二糖磷酸化酶和纤维寡糖磷酸化酶的研究与应用

Research and application of cellobiose phosphorylase and cellodextrin phosphorylase: a review

自然界中一些厌氧的纤维素降解菌能够产生纤维二糖磷酸化酶(Cellobiose Phosphorylase,CBP)和纤维寡糖磷酸化酶(CellodextrinPhosphorylase,CDP)磷酸化裂解纤维二糖和纤维寡糖。CBP和CDP属于糖苷水解酶94家族(Glycoside Hydrolase Family 94,GH94),对β-1,4糖苷键高度专一。目前已广泛研究了不同来源的CBP和CDP的功能性质和催化机理,并通过蛋白质晶体结构分析揭示了二者采用不同聚合度纤维寡糖作为底物的结构基础。因CBP和CDP可催化独特的磷酸化裂解反应和逆向合成反应,已有多篇报道显示CBP和CDP在生产实践上的应用,主要在构建直接利用纤维寡糖的工程酵母菌、构建酶法纤维素转淀粉体系和酶法合成特殊糖类等3个方面。由于对CBP和CDP的持续关注,在此对二者的相关研究进行综述,并提出今后的研究重点。

In nature some anaerobic cellulolytic bacteria can produce cellobiose phosphorylase(CBP) and cellodextrin phosphorylase(CDP) in order to phosphorolyze cellobiose and cellodextrins, respectively. Both CBPs and CDPs belong to glycoside hydrolase family 94(GH94), which have a high specificity for β-1,4-linked glycosidic bonds. At present, the properties and catalytic mechanism of CBPs and CDPs from different strains of bacteria have been extensively studied, and analysis of the protein crystal structures have revealed the structure basis of the two phosphorylases for catalyzing different substrates regarding their degree of polymerization. Because of the unique phosphorolytic reactions and reverse synthetic reactions CBPs and CDPs can catalyze, there have been many reports showing their applications which mainly include three aspects: construction of engineered yeasts that directly use cellodextrins, construction of enzymatic conversion pathway of cellulose to starch, and enzymatic synthesis of special sugars. Due to the rising interest in CBPs and CDPs, here we have reviewed the related studies and provided some perspectives about the future research areas.