Xu Zheng, Li Sha, Feng Xiaohai, Liang Jinfeng, Xu Hong
State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, 210009, People's Republic of China.
Appl Microbiol Biotechnol. 2014 Nov;98(21):8869-78. doi: 10.1007/s00253-014-6073-0. Epub 2014 Oct 4.
L-Arabinose isomerase (AI), a key enzyme in the microbial pentose phosphate pathway, has been regarded as an important biological catalyst in rare sugar production. This enzyme could isomerize L-arabinose into L-ribulose, as well as D-galactose into D-tagatose. Both the two monosaccharides show excellent commercial values in food and pharmaceutical industries. With the identification of novel AI family members, some of them have exhibited remarkable potential in industrial applications. The biological production processes for D-tagatose and L-ribose (or L-ribulose) using AI have been developed and improved in recent years. Meanwhile, protein engineering techniques involving rational design has effectively enhanced the catalytic properties of various AIs. Moreover, the crystal structure of AI has been disclosed, which sheds light on the understanding of AI structure and catalytic mechanism at molecular levels. This article reports recent developments in (i) novel AI screening, (ii) AI-mediated rare sugar production processes, (iii) molecular modification of AI, and (iv) structural biology study of AI. Based on previous reports, an analysis of the future development has also been initiated.
L-阿拉伯糖异构酶（AI）是微生物磷酸戊糖途径中的关键酶，被视为稀有糖生产中的重要生物催化剂。该酶可将L-阿拉伯糖异构化为L-核糖ulose，也可将D-半乳糖异构化为D-塔格糖。这两种单糖在食品和制药行业均具有出色的商业价值。随着新型AI家族成员的鉴定，其中一些在工业应用中展现出了显著潜力。近年来，利用AI生产D-塔格糖和L-核糖（或L-核糖ulose）的生物生产工艺得到了发展和改进。同时，涉及合理设计的蛋白质工程技术有效地提高了各种AI的催化性能。此外，AI的晶体结构已被揭示，这有助于从分子水平理解AI的结构和催化机制。本文报道了（i）新型AI筛选、（ii）AI介导的稀有糖生产工艺、（iii）AI的分子修饰以及（iv）AI的结构生物学研究方面的最新进展。基于先前的报道，还对未来发展进行了分析。
