Thermostable alpha-galactosidase from Bacillus stearothermophilus NUB3621: cloning, sequencing and characterization.
Thermostable alpha-galactosidase from Bacillus stearothermophilus NUB3621: cloning, sequencing and characterization.
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DOI：
10.1111/j.1574-6968.1999.tb13655.x
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发表时间：
1999-07
影响因子：
2.1
通讯作者：
Ó. Fridjónsson;H. Watzlawick;A. Gehweiler;R. Mattes
中科院分区：
文献类型：
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作者：
Ó. Fridjónsson;H. Watzlawick;A. Gehweiler;R. Mattes
从嗜热脂肪芽孢杆菌（Bacillus stearothermophilus）NUB 3621中克隆了α-半乳糖苷酶基因，并进行了序列测定、原核表达和纯化。命名为AgaN的芽孢杆菌酶在糖基水解酶的分类中与家族36的α-半乳糖苷酶相似。估计该酶是一个四聚体，亚基分子量为80.3 kDa。纯化的AgaN是热稳定的，并且在75 ° C具有最佳活性温度，在70 ° C具有19小时的失活半衰期。AgaN对低聚底物如蜜二糖和棉子糖显示出高亲和力，并且能够在60%蔗糖存在下高效水解棉子糖。
An alpha-galactosidase gene from the thermophilic bacterium Bacillus stearothermophilus NUB3621 was cloned, sequenced, expressed in Escherichia coli and the recombinant protein was purified. The Bacillus enzyme, designated AgaN, is similar to alpha-galactosidases of family 36 in the classification of glycosyl hydrolases. The enzyme was estimated to be a tetramer with a molecular mass of subunits 80.3 kDa. The purified AgaN is thermostable and has a temperature optimum of activity at 75 degrees C and a half-life of inactivation of 19 h at 70 degrees C. AgaN displays high affinity for oligomeric substrates such as melibiose and raffinose and is able to hydrolyze raffinose in the presence of 60% sucrose with high efficiency.