Characterization of a highly thermostable glycoside hydrolase family 10 xylanase from Malbranchea cinnamomea
Characterization of a highly thermostable glycoside hydrolase family 10 xylanase from Malbranchea cinnamomea
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DOI：
10.1016/j.ijbiomac.2014.07.025
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发表时间：
2014-09-01
影响因子：
8.2
通讯作者：
Jiang, Zhengqiang
中科院分区：
文献类型：
--
作者：
Fan, Guangsen;Yang, Shaoqing;Jiang, Zhengqiang
对来自嗜热真菌 Malbranchea cinnamomea 菌株 S168 的耐热木聚糖酶 (McXyn10) 进行了纯化和生化表征。该酶在 SDS-PAGE 上纯化至均质，分子量为 43.5 kDa。纯化酶的最适pH和温度分别为pH 6.5和80℃。该酶表现出广泛的 pH 稳定性（pH 4.0-10.5），在 70 摄氏度以下稳定，热变性半衰期为 76.0 分钟。该酶对各种木聚糖作为底物表现出严格的特异性，但对其他测试的多糖没有表现出活性。 McXyn10水解桦木木聚糖、山毛榉木木聚糖和燕麦木聚糖，主要产生木二糖、木三糖和聚合度(DP)在5以上的低聚木糖，同时由木三糖和木四糖产生木二糖。进一步克隆了木聚糖酶基因。它有一个 1191 bp 的开放阅读框，有两个内含子。该基因的推导氨基酸序列与出芽短梗霉的糖苷水解酶家族 10 木聚糖酶具有最高的同一性 (58%)。 (C) 2014 Elsevier B.V. 保留所有权利。
A thermostable xylanase (McXyn10) from the thermophilic fungus Malbranchea cinnamomea strain S168 was purified and biochemically characterized. The enzyme was purified to homogeneity with a molecular mass of 43.5 kDa on SDS-PAGE. The optimal pH and temperature of the purified enzyme were pH 6.5 and 80 degrees C, respectively. The enzyme showed a broad range of pH stability (pH 4.0-10.5), and was stable up to 70 degrees C with a thermal denaturing half life of 76.0 min. The enzyme exhibited strict specificity for various xylans as substrates, but displayed no activity toward other tested polysaccharides. McXyn10 hydrolyzed birchwood xylan, beechwood xylan and oat-spelt xylan, yielded mainly xylobiose, xylotriose and xylooligosaccharides with degree of polymerization (DP) above 5, while yielded xylobiose from xylotriose and xylotetraose. The xylanase gene was further cloned. It had an open reading frame of 1191 bp with two introns. The deduced amino acid sequence of the gene showed highest identity (58%) with a glycoside hydrolase family 10 xylanase from Aureobasidium pullulans. (C) 2014 Elsevier B.V. All rights reserved.