School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China.
Biotechnol Lett. 2013 Sep;35(9):1433-40. doi: 10.1007/s10529-013-1220-8. Epub 2013 May 21.
A putative endo-1,4-β-D-xylanohydrolase gene xyl10 from Aspergillus niger, encoding a 308-residue mature xylanase belonging to glycosyl hydrolase family 10, was constitutively expressed in Pichia pastoris. The recombinant Xyl10 exhibited optimal activity at pH 5.0 and 60 °C with more than 50 % of the maximum activity from 40 to 70 °C. It retained more than 90 % of the original activity after incubation at 60 °C (pH 5.0) for 30 min and more than 74 % after incubation at pH 3.0-13.0 for 2 h (25 °C). The specific activity, K m and V max values for purified Xyl10 were, respectively, 3.2 × 10(3) U mg(-1), 3.6 mg ml(-1) and 5.4 × 10(3) μmol min(-1 )mg(-1) towards beechwood xylan. The enzyme degraded xylan to a series of xylooligosaccharides and xylose. The recombinant enzyme with these properties has the potential for various industrial applications.
黑曲霉的假定内切-1,4-β-D-木聚糖水解酶基因 xyl10 被组成型表达于巴斯德毕赤酵母中，编码一个 308 个残基的成熟木聚糖酶，属于糖苷水解酶家族 10。重组 Xyl10 在 pH 5.0 和 60°C 下表现出最佳活性，在 40 至 70°C 之间具有超过 50%的最大活性。在 60°C（pH 5.0）下孵育 30 分钟后，它保留了超过 90%的原始活性，在 pH 3.0-13.0 下孵育 2 小时（25°C）后保留了超过 74%的原始活性。纯化的 Xyl10 的比活性、K m 和 V max 值分别为 3.2×10(3)U mg(-1)、3.6mg ml(-1)和 5.4×10(3)μmol min(-1)mg(-1)，对桦木木聚糖具有活性。该酶将木聚糖降解为一系列低聚木糖和木糖。具有这些特性的重组酶具有在各种工业应用中的潜力。
