An acidophilic and acid-stable beta-mannanase from phialophora sp. p13 with high mannan hydrolysis activity under simulated gastric conditions.
An acidophilic and acid-stable beta-mannanase from phialophora sp. p13 with high mannan hydrolysis activity under simulated gastric conditions.
复制标题
DOI：
10.1021/jf904367r
复制
发表时间：
2010-02
影响因子：
6.1
通讯作者：
Junqi Zhao;P. Shi;Huiying Luo;Peilong Yang;Heng Zhao;Yingguo Bai;Huo-qing Huang;Hui Wang;B. Yao
中科院分区：
文献类型：
--
作者：
Junqi Zhao;P. Shi;Huiying Luo;Peilong Yang;Heng Zhao;Yingguo Bai;Huo-qing Huang;Hui Wang;B. Yao
从瓶霉（Phialophora sp.P13）中克隆了β-甘露聚糖酶基因man 5AP 13，并在毕赤酵母（Pichia pastoris）中表达。成熟酶MAN 5AP 13的推导氨基酸序列与来自Bispora sp. MEY-1的糖苷水解酶家族5 β-甘露聚糖酶具有最高的同一性（53%）。纯化的重组β-甘露聚糖酶是嗜酸的和酸稳定的，在pH 1.5下表现出最大活性，并且在pH 1.5-7.0范围内保持>60%的初始活性。最适温度为60 ℃。刺槐豆胶底物的比活性、K（m）和V（max）分别为851 U/mg、2.5 mg/mL和1667.7 U/min.mg。该酶在模拟胃液条件下具有良好的活性和稳定性，在含胃蛋白酶的模拟胃液中刺槐豆胶还原糖的释放量比不含胃蛋白酶的模拟胃液中高1倍。所有这些特性使MAN 5AP 13成为食品和饲料工业中潜在的添加剂。
A beta-mannanase gene, man5AP13, was cloned from Phialophora sp. P13 and expressed in Pichia pastoris. The deduced amino acid sequence of the mature enzyme, MAN5AP13, had highest identity (53%) with the glycoside hydrolase family 5 beta-mannanase from Bispora sp. MEY-1. The purified recombinant beta-mannanase was acidophilic and acid stable, exhibiting maximal activity at pH 1.5 and retaining >60% of the initial activity over the pH range 1.5-7.0. The optimum temperature was 60 degrees C. The specific activity, K(m) and V(max) for locust bean gum substrate were 851 U/mg, 2.5 mg/mL, and 1667.7 U/min.mg, respectively. The enzyme had excellent activity and stability under simulated gastric conditions, and the released reducing sugar of locust bean gum was significantly enhanced by one-fold in simulated gastric fluid containing pepsin in contrast to that without pepsin. All these properties make MAN5AP13 a potential additive for use in the food and feed industries.