Active Hydrogen Bond Network (AHBN) and Applications for Improvement of Thermal Stability and pH-Sensitivity of Pullulanase from Bacillus naganoensis.
Active Hydrogen Bond Network (AHBN) and Applications for Improvement of Thermal Stability and pH-Sensitivity of Pullulanase from Bacillus naganoensis.
复制标题
活性氢键网络 (AHBN) 及其在改善长野芽孢杆菌普鲁兰酶热稳定性和 pH 敏感性方面的应用
DOI：
10.1371/journal.pone.0169080
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Huang RB
中科院分区：
文献类型：
--
作者：
Wang QY;Xie NZ;Du QS;Qin Y;Li JX;Meng JZ;Huang RB
一种被称为“活性氢键网络”（AHBN）的方法被提出用于水解酶的位点定向突变。在酶中，AHBN由活性残基、功能残基和保守的水分子组成，它们通过氢键连接在一起，形成一个三维网络。在水解酶的催化水解反应中，AHBN负责质子和水分子的运输，维持酶的活性和动态结构。根据pullulanase BAPulA （2WAN）的模板结构，利用Swiss model Protein-modeling Server基于同源模型结构构建了长野芽孢杆菌pullulanase BNPulA324的AHBN。pululanase BNPulA324在AHBN法选择的突变位点发生突变。成功地提高了普鲁兰酶BNPulA324的热稳定性和ph敏感性。位于AHBN外缘残基的突变可能产生积极的影响。另一方面，AHBN内部残基的突变可能会剥夺酶的生物活性。本研究提出的AHBN方法可为蛋白质合理设计和蛋白质工程提供辅助和替代工具。
A method, so called “active hydrogen bond network” (AHBN), is proposed for site-directed mutations of hydrolytic enzymes. In an enzyme the AHBN consists of the active residues, functional residues, and conservative water molecules, which are connected by hydrogen bonds, forming a three dimensional network. In the catalysis hydrolytic reactions of hydrolytic enzymes AHBN is responsible for the transportation of protons and water molecules, and maintaining the active and dynamic structures of enzymes. The AHBN of pullulanase BNPulA324 from Bacillus naganoensis was constructed based on a homologous model structure using Swiss Model Protein-modeling Server according to the template structure of pullulanase BAPulA (2WAN). The pullulanase BNPulA324 are mutated at the mutation sites selected by means of the AHBN method. Both thermal stability and pH-sensitivity of pullulanase BNPulA324 were successfully improved. The mutations at the residues located at the out edge of AHBN may yield positive effects. On the other hand the mutations at the residues inside the AHBN may deprive the bioactivity of enzymes. The AHBN method, proposed in this study, may provide an assistant and alternate tool for protein rational design and protein engineering.