Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Beijing 100048, China; School of Food and Chemical Engineering, Beijing Technology and Business University, No.33, Fucheng Road, Beijing 100048, China.
Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Beijing 100048, China; Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University (BTBU), Beijing 100048, China.
Int J Biol Macromol. 2018 Feb;107(Pt B):1447-1455. doi: 10.1016/j.ijbiomac.2017.10.013. Epub 2017 Oct 10.
A GH10 xylanase Srxyn10 from Streptomyce rochei L10904, and its truncated derivative, Srxyn10M, were investigated. Both displayed great salt-tolerant ability, retaining more than 95% and 91% activity after incubation at 37°C for 1h in 3.0M and 5.0M NaCl, respectively. They exhibited a special hydrolytic property of forming xylobiose as the major product and produced fewer xylose compounds when combined with a reported xylanase while digesting corncob xylans. The mutant, Srxyn10M, was constructed from Srxyn10 by deleting the C-terminal carbohydrate-binding module. It possessed a 3.26-fold higher specific activity on beechwood xylan than Srxyn10. Moreover, Srxyn10M showed greater substrate affinity and catalytic efficiency than Srxyn10 when beechwood xylan, birchwood xylan, and oat-spelt xylan were used as substrates. The thermostability was also greatly improved. Therefore, the application potential was markedly enhanced by the improvement of these properties.
从罗氏链霉菌 L10904 中分离得到 GH10 木聚糖酶 Srxyn10 及其截断衍生物 Srxyn10M，并对其进行了研究。两种酶均具有很强的耐盐能力，在 37°C 下分别在 3.0M 和 5.0M NaCl 中孵育 1h 后，仍保持超过 95%和 91%的活性。与报道的木聚糖酶结合消化玉米芯木聚糖时，它们表现出一种特殊的水解特性，即形成木二糖作为主要产物，产生较少的木糖化合物。突变体 Srxyn10M 是通过删除 Srxyn10 的 C 端碳水化合物结合模块构建的。与 Srxyn10 相比，它在桦木木聚糖上的比活性提高了 3.26 倍。此外，当以桦木木聚糖、桦木木聚糖和燕麦黑麦草木聚糖为底物时，Srxyn10M 比 Srxyn10 具有更高的底物亲和力和催化效率。热稳定性也得到了极大的提高。因此，这些性质的改善显著提高了其应用潜力。
