Effects of different carbohydrate-binding modules on the enzymatic properties of pullulanase
Effects of different carbohydrate-binding modules on the enzymatic properties of pullulanase
复制标题
不同碳水化合物结合模块对普鲁兰酶酶学性质的影响
DOI：
10.1016/j.ijbiomac.2019.07.054
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发表时间：
2019-09-15
影响因子：
8.2
通讯作者：
Song, Hui
中科院分区：
文献类型：
--
作者：
Zeng, Yan;Xu, Jianyong;Song, Hui
普鲁兰酶的一些特定性质通常与其特定的N-末端CBM有很大关系。本文主要研究了耐热普鲁兰酶PulA中新的碳水化合物结合模块CBM 68的性质。为了揭示其与酸性普鲁兰酶PulB的共同模块CBM 41/CBM 41-X45不同的性质，构建了12个重组普鲁兰酶，并将其命名为Pul-1，与Pul-12相似。通过对它们的热稳定性、pH曲线和动力学参数的比较分析，得出了一些规律。与CBM 41相比，位于分子N端的CBM 68使普鲁兰酶具有更高的热稳定性、底物亲和力和催化效率。而CBM 41在提高普鲁兰酶的酸稳定性方面优于CBM 68。X45可以帮助普鲁兰酶正确折叠，并对普鲁兰酶的催化结构域有影响。PulA或PulB的催化结构域对普鲁兰酶的最适pH和催化效率有重要影响。此外，通过优化CBM 41-X45与PulA催化结构域的组合，使Pul-7的催化效率最高（1284.68 mL/mg.s），是PulA（737.78 mL/mg.s）的1.74倍。本研究揭示的CBM 68、CBM 41和CBM 41-X45的特性为合理设计普鲁兰酶提供了依据。(C)2019爱思唯尔B. V.保留所有权利。
Some specific properties of pullulanases usually have a great deal to do with their specific N-terminal CBMs. This paper focusses on characters of the novel carbohydrate-binding module CBM68 from a thermostable pullulanase PulA. As to reveal its different properties with the common module CBM41/CBM41-X45 (from an acid pullulanase PulB), twelve recombinant pullulanases were constructed and named as Pul-1 similar to Pul-12 respectively. Through comparative analysis of their thermostabilities, pH profiles, and kinetic parameters, some rules have been concluded. Compared with CBM41, CBM68 on the N-terminal of molecules could make pullulanases more thermostable, have higher substrate affinity, and have higher catalytic efficiency. While CBM41 had the advantage on improving the acidic stability of pullulanase comparing with CBM68. X45 could help pullulanases fold properly and has impact to the catalytic domains of pullulanase. The catalytic domain of PulA or PulB played important roles in the optimum pH and catalytic efficiency of pullulanases. Moreover, the optimal combination of CBM41-X45 and the catalytic domain of PulA made Pul-7 have the highest catalytic efficiency (1284.68 mL/mg.s) which was 1.74 times higher than that (737.78 mL/mg.s) of PulA. The characteristics of CBM68, CBM41 and CBM41-X45 revealed in this study would serve as a basis for rational design of pullulanases. (C) 2019 Elsevier B.V. All rights reserved.