Characterization of a novel hydroxynitrile lyase from Nandina domestica Thunb
Characterization of a novel hydroxynitrile lyase from Nandina domestica Thunb
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DOI：
10.1080/09168451.2018.1490171
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发表时间：
2018-01-01
影响因子：
1.6
通讯作者：
Asano, Yasuhisa
中科院分区：
文献类型：
--
作者：
Isobe, Kimiyasu;Kitagawa, Asuka;Asano, Yasuhisa
南天竹的叶子。在（R）-扁桃腈合成中显示出高的羟基腈裂解酶（HNL）活性。幼叶比活性显著高于成熟叶。我们从幼叶中分离到两个分子量为24.9 kDa（NdHNL-S）和28.0 kDa（NdHNL-L）的HNL。两种NdHNL均由两个相同的亚基组成，不含FAD和碳水化合物。我们纯化了NdHNL-L并揭示了其酶性质。NdHNL-L的氨基酸序列与其它HNLs没有同源性，其合成扁桃腈的比活性高于其它植物HNLs。该酶催化（R）-氰醇的对映选择性合成，在pH 4.0下表现出高活性，并且在pH 3.5-8.0和低于55 ℃的范围内具有高稳定性。因此，NdHNL-L是一种具有新氨基酸序列的新型HNL，具有高效生产（R）-氰醇的潜力。
The leaves of Nandina domestica Thunb. exhibited high hydroxynitrile lyase (HNL) activity in (R)-mandelonitrile synthesis. The specific activity of young leaves was significantly higher than that of mature leaves. We isolated two HNLs with molecular mass of 24.9 kDa (NdHNL-S) and 28.0 kDa (NdHNL-L) from the young leaves. Both NdHNLs were composed of two identical subunits, without FAD and carbohydrates. We purified NdHNL-L and revealed its enzymatic properties. The whole deduced amino acid sequence of NdHNL-L was not homologous to any other HNLs, and the specific activity for mandelonitrile synthesis by NdHNL-L was higher than that by other plant HNLs. The enzyme catalyzed enantioselective synthesis of (R)-cyanohydrins, exhibited high activity at pH 4.0, and high stability in the pH range of 3.5-8.0 and below 55 degrees C. Thus, NdHNL-L is a novel HNL with novel amino acid sequence and has a potential for the efficient production of (R)-cyanohydrins.