木糖异构酶序列结构特点、耐热机理及分子改造研究进展

Progress in the sequence and structure properties, thermostability mechanism and molecular modification of xylose isomerase: a review

摘要:

近年来，随着发展低碳经济的迫切需要，可再生资源利用研究方兴未艾，其中，构建充分利用木质纤维素水解产物木糖生产乙醇的重组菌成为研究热点。木糖异构酶由于不需要辅酶，成为构建利用木糖重组酵母的首选途径。文中对近年来木糖异构酶的研究进展进行了综述。首先介绍了木糖异构酶的基本性质、序列、结构和功能特性，然后对其耐热机理进行了总结归纳；重点阐述了基于序列及结构进行的酶分子改造研究，包括底物特异性改造、热稳定性改造等；同时，结合作者的研究经历，对如何提高嗜热木糖异构酶在常温下的活性进行了探讨。最后，对木糖异构酶的研究进展进行了总结和展望，对基于结构改善木糖异构酶催化活性及构建新型高效利用木糖生产乙醇的重组菌具有重要的指导意义。

Abstract:

With the development of low-carbon economy and renewable resource, fermentation of the pentose sugar xylose to produce ethanol becomes a very hot topic. The recombinant Saccharomyces cerevisiae can be constructed by expressing heterologous xylose isomerase (XI). Because Thermus thermophilus XI (TthXI) does not need cofactor, it has been developed for establishing the utilization pathway of xylose in S. cerevisiae. In this article, we reviewed the progress on xylose isomerase. We first introduced the primary properties, sequence and structure characters of xylose isomerase, and discussed its thermostability. The molecular modification of xylose isomerase, including of substrate specificity and thermostability were discussed in detail. Meanwhile, combined with our own research, we also discussed how to improve the xylose isomerase activity at room temperature. Finally, we suggested perspectives of xylose isomerase.