Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun, 130012, China.
School of Chemistry and Life Science, Changchun University of Technology, Changchun, 130012, China.
Sci Rep. 2022 Mar 10;12(1):3978. doi: 10.1038/s41598-022-08036-z.
In the process of yielding biofuels from cellulose degradation, traditional enzymatic hydrolysis, such as β-glucosidase catalyzing cellobiose, can barely resolve the contradiction between cellulose degradation and bioenergy conservation. However, it has been shown that cellobiose phosphorylase provides energetic advantages for cellobiose degradation through a phosphorolytic pathway, which has attracted wide attention. Here, the cellobiose phosphorylase gene from Caldicellulosiruptor bescii (CbCBP) was cloned, expressed, and purified. Analysis of the enzymatic properties and kinetic mechanisms indicated that CbCBP catalyzed reversible phosphorolysis and had good thermal stability and broad substrate selectivity. In addition, the phosphorolytic reaction of cellobiose by CbCBP proceeded via an ordered Bi Bi mechanism, while the synthetic reaction proceeded via a ping pong Bi Bi mechanism. The present study lays the foundation for optimizing the degradation of cellulose and the synthesis of functional oligosaccharides.
在利用纤维素降解生产生物燃料的过程中，传统的酶解方法，如β-葡萄糖苷酶催化纤维二糖，几乎无法解决纤维素降解与生物能保存之间的矛盾。然而，已有研究表明，纤维二糖磷酸化酶通过磷酸解途径为纤维二糖的降解提供了能量优势，这引起了广泛关注。本研究从 Caldicellulosiruptor bescii（CbCBP）中克隆、表达和纯化了纤维二糖磷酸化酶基因。对酶学性质和动力学机制的分析表明，CbCBP 可催化可逆的磷酸解反应，具有良好的热稳定性和广泛的底物选择性。此外，CbCBP 催化的纤维二糖的磷酸解反应遵循有序的双底物结合机制，而合成反应则遵循乒乓双底物结合机制。本研究为优化纤维素的降解和功能性寡糖的合成奠定了基础。
