Hydrolytic activity of α-galactosidases against deoxy derivatives of p-nitrophenyl α-D-galactopyranoside
Hydrolytic activity of α-galactosidases against deoxy derivatives of p-nitrophenyl α-D-galactopyranoside
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DOI：
10.1016/s0008-6215(99)00281-5
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发表时间：
2000-02-11
影响因子：
3.1
通讯作者：
Oku, T
中科院分区：
文献类型：
--
作者：
Hakamata, W;Nishio, T;Oku, T
合成了4种可能的对硝基苯基（PNP）α-D-吡喃半乳糖苷单脱氧衍生物，并研究了绿色咖啡豆、葡萄被孢霉和黑曲霉α-半乳糖苷酶对它们的水解活性。利用绿色咖啡豆和M.而对3-和4-脱氧化合物几乎不起作用。另一方面，A.黑尼日尔α-半乳糖苷酶仅水解这些脱氧底物中的2-脱氧化合物，并且活性非常高。这些结果表明，两个羟基（OH-3和-4）的存在是必不可少的化合物作为底物的酶的绿色咖啡豆和M。而三个羟基（OH-3、OH-4和OH-6）是A. vinacea活性所必需的。尼日尔酶通过动力学研究，获得了酶水解PNP α-D-吡喃半乳糖苷及其脱氧衍生物的动力学参数（Km和Vmax）。(C)2000爱思唯尔科技有限公司版权所有。
The four possible monodeoxy derivatives of p-nitrophenyl (PNP) alpha-D-galactopyranoside were synthesized, and hydrolytic activities of the alpha-galactosidase of green coffee bean, Mortierella vinacea and Aspergillus niger against them were elucidated. The 2- and 6-deoxy substrates were hydrolyzed by the enzymes from green coffee bean and M. vinacea, while they scarcely acted on the 3- and 4-deoxy compounds. On the other hand, A. niger alpha-galactosidase hydrolyzed only the 2-deoxy compound in these deoxy substrates, and the activity was very high. These results indicate that the presence of two hydroxyl groups (OH-3 and -4) is essential for the compounds to act as substrates for the enzymes of green coffee bean and M. vinacea, while the three hydroxyl groups (OH-3, -4, and -6) are necessary for the activity of the A. niger enzyme. The kinetic parameters (K-m and V-max) of the enzymes for the hydrolysis of PNP alpha-D-galactopyranoside and its deoxy derivatives were obtained from kinetic studies. (C) 2000 Elsevier Science Ltd. All rights reserved.