木聚糖酶TgXyn2的酶学特性研究

Enzymatic Characterization of Xylanase TgXyn2

摘要: 目的：本研究旨在发掘和研究一种新的低温酸性内切- 1,4 -β-木聚糖酶TgXyn2并研究其酶学特性，为其在食品等轻工业生产中的实际应用提供理论依据。方法：利用pCold-TF表达质粒在大肠杆菌中异源表达，纯化后检测其酶学特性，并通过同源建模分析其三维结构。结果：该酶的最适温度为35 ℃，最适pH为5.0，K_m为1.287 μmol L⁻¹，V_max为2.083 μmol min⁻¹ mg⁻¹；同源建模结果表明，TgXyn2由2个反向平行的β-折叠和1个α-螺旋构成，是典型的糖苷水解酶GH11家族木聚糖酶。结论：本文研究的TgXyn2具有良好的酶学特性，在食品等行业具有较好的应用潜力。

Abstract: Objectives: This study aimed to discover a acidic xylanase TgXyn2 with high enzymatic activities at low temperatures, which might have potential application in food industry. Method: TgXyn2 was heterologously expressed in E.coli with the expression vector pCold-TF. Results: The optimum reaction condition of TgXyn2 was 35 ℃ and pH5.0, respectively. Its K_m was 1.287 μmol L⁻¹ and V_max was 2.083 μmol min⁻¹ mg⁻¹. Homology modeling showed that TgXyn2 had two antiparallel β-sheets and an α-helix, which was typical for the GH11 family. Conclusions: TgXyn2 had good enzymatic activities, which has potential application in food industry.