Expression and characterization of recombinant GH11 xylanase from thermotolerant Streptomyces sp. SWU10
Expression and characterization of recombinant GH11 xylanase from thermotolerant Streptomyces sp. SWU10
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耐热链霉菌重组 GH11 木聚糖酶的表达和表征。
DOI：
10.1007/s12010-013-0508-4
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
T.
中科院分区：
文献类型：
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作者：
Sukhumsirichart;W. Deesukon;W. Kawakami;T. Matsumoto;S. Seesom;W. Sakamoto;T.
木聚糖是植物细胞壁的主要半纤维素成分，可被木聚糖分解酶水解。由耐热链霉菌产生的三种形式的内切-β-1,4-木聚糖酶（XynSW1、XynSW2A 和 XynSW2B）。 SWU10已被报道。在本研究中，我们描述了该细菌中第四种木聚糖酶（称为 XynSW3）的表达和特征。含有 726 bp 的基因被克隆并在大肠杆菌中表达。使用 Ni 亲和柱层析将重组酶 (rXynSW3) 从无细胞提取物中纯化至均质。 rXynSW3 的表观分子质量为 48 kDa。氨基酸序列分析表明它属于糖苷水解酶家族11的木聚糖酶。酶活性的最适pH和温度分别为5.5-6.5和50°C。该酶在高达 40 °C 的温度和较宽的 pH 范围内 (pH 0.6–10.3) 保持稳定。没有阿拉伯糖侧链的木聚糖是该酶最优选的底物。以桦木木聚糖为底物，rXynSW3在水解初期产生多种寡糖，并且其水平随着时间的推移而增加，表明该酶是一种内作用酶。主要产品是木二糖、丙糖和四糖。 rXynSW3 可应用于食品、纺织、生物燃料行业以及废物处理等多个行业。
Xylans are major hemicellulose components of plant cell wall which can be hydrolyzed by xylanolytic enzymes. Three forms of endo-β-1,4-xylanases (XynSW1, XynSW2A, and XynSW2B) produced by thermotolerantStreptomycessp. SWU10 have been reported. In the present study, we described the expression and characterization of the fourth xylanase enzyme from this bacteria, termed XynSW3. The gene containing 726 bp was cloned and expressed inEscherichia coli. The recombinant enzyme (rXynSW3) was purified from cell-free extract to homogeneity using Ni-affinity column chromatography. The apparent molecular mass of rXynSW3 was 48 kDa. Amino acid sequence analysis revealed that it belonged to a xylanase of glycoside hydrolase family 11. The optimum pH and temperature for enzyme activity were 5.5–6.5 and 50 °C, respectively. The enzyme was stable up to 40 °C and in wide pH ranges (pH 0.6–10.3). Xylan without arabinosyl side chain is the most preferable substrate for the enzyme. By using birch wood xylan as substrate, rXynSW3 produced several oligosaccharides in the initial stage of hydrolysis, and their levels increased with time, demonstrating that the enzyme is an endo-acting enzyme. The major products were xylobiose, triose, and tetraose. The rXynSW3 can be applied in several industries such as food, textile, and biofuel industries, and waste treatment.