α-Galactosidase purified from Bifidobacterium longum JCM 7052 grown on gum arabic
α-Galactosidase purified from Bifidobacterium longum JCM 7052 grown on gum arabic
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从阿拉伯树胶上生长的长双歧杆菌 JCM 7052 中纯化的 α-半乳糖苷酶
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
I. Yamamoto
中科院分区：
文献类型：
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作者：
Naoko Saishin;I. Yamamoto
其中长双歧杆菌JCM 7052在阿拉伯胶培养基中生长良好，并具有较高的α-半乳糖苷酶和β-半乳糖苷酶活性。α-半乳糖苷酶从B纯化66倍。longum JCM 7052通过硫酸铵分级分离在阿拉伯树胶上生长，并在Sepharose 4 B、Q-Sepharose、Butyl-S Sepharose和羟基磷灰石上层析。该酶的表观分子量为79 kDa的十二烷基硫酸钠（SDS）-聚丙烯酰胺凝胶电泳（PAGE）和150 kDa的聚丙烯酰胺凝胶电泳无SDS，表明二聚体的酶的性质。该酶在pH8.0和40-45°C下具有最佳活性。α-半乳糖苷的水解表现出正常的饱和动力学：4-硝基苯基-α-D-吡喃半乳糖苷、棉子糖和水苏糖的Km值分别为0.15、88.3和126 mM。三羟甲基氨基甲烷对α-半乳糖苷酶活性有竞争性抑制作用，Ki值为32 mM，对硝基苯基-α-D-吡喃半乳糖苷也有转半乳糖基化活性，可转化为半乳糖和蜜二糖。
Among some strains, Bifidobacterium longum JCM 7052 grew well anaerobically in a medium with gum arabic, and showed high activities of αand β-galactosidases. α-Galactosidase was purified 66-fold from B. longum JCM 7052 grown on gum arabic by ammonium sulfate fractionation, and chromatographies on Sepharose 4B, Q-Sepharose, Butyl-S Sepharose, and hydroxyapatite. The enzyme had an apparent molecular mass of 79 kDa by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) and 150 kDa by PAGE without SDS, suggesting the dimeric nature of the enzyme. This α-galactosidase showed optimal activity at pH 8.0 and at 40–45°C. Hydrolysis of α-galactosides showed normal saturation kinetics: Km values for 4-nitrophenyl-α-D-galactopyranoside, raffinose, and stachyose were 0.15, 88.3, and 126 mM, respectively. The activity of α-galactosidase was inhibited competitively by tris (hydroxymethyl) aminomethane: its Ki was 32 mM. Transgalactosylation activity was also observed from 4-nitrophenyl-α-D-galactopyranoside to galactose and melibiose.
影响因子：
4.8
作者：
Fujita, K;Oura, F;Yamamoto, K
通讯作者：
Yamamoto, K