Heterologous expression and characterization of an Arabidopsis β-l-arabinopyranosidase and α-d-galactosidases acting on β-l-arabinopyranosyl residues.
Heterologous expression and characterization of an Arabidopsis β-l-arabinopyranosidase and α-d-galactosidases acting on β-l-arabinopyranosyl residues.
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DOI：
10.1093/jxb/erx279
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发表时间：
2017-07-20
影响因子：
6.9
通讯作者：
Kotake T
中科院分区：
文献类型：
--
作者：
Imaizumi C;Tomatsu H;Kitazawa K;Yoshimi Y;Shibano S;Kikuchi K;Yamaguchi M;Kaneko S;Tsumuraya Y;Kotake T
通过对毕赤酵母中表达的突变体和重组酶的分析，发现拟南芥β-l-arabinopyranosidase和α-d-半乳糖苷酶参与了β-l- arabinopyranosyyl残基的水解。主要的植物糖l-阿拉伯糖（l-Ara）有两种不同的环状形式，l-阿拉伯糖ofuranose （l-Araf）和l-阿拉伯糖吡喃糖（l-Arap）。虽然l-Ara主要以α-l-Araf残基的形式出现在果胶α-1,3:1,5-阿拉伯聚糖、阿拉伯木聚糖和阿拉伯半乳糖蛋白（AGPs）等细胞壁组分中，但也有少量的l-Ara残基出现在AGPs的β-l-Arap残基中。尽管已知AGPs可快速代谢，但作用于β-l-Arap残基的酶仍有待鉴定。在本研究中，我们确定了四种酶，我们称之为β-l-ARAPASE （APSE）和α-半乳糖sidase 1 (AGAL1)， AGAL2和AGAL3，这些酶可能负责在拟南芥中水解β-l-Arap残基。拟南芥apse-1突变体显示β-l-阿拉伯吡喃葡萄糖苷酶活性显著降低，而apse-1 agal3-1双突变体表现出更低的活性。apase -1和双突变体细胞壁中β-l-Arap残基含量均高于野生型植株。在酵母毕赤酵母中表达的重组磷酸腺苷可水解阿拉伯树胶和落叶松半乳聚糖中的β-l-Arap残基并释放l-Ara。重组AGAL3除了具有较强的α-半乳糖苷酶活性外，还表现出较弱的β-l-阿拉伯葡萄糖苷酶活性。在拟南芥中，AGPs的β-l-Arap残基主要被APSE水解，部分被AGALs水解。
Through the analysis of mutants and recombinant enzymes expressed in Pichia yeast, an Arabidopsis β-l-arabinopyranosidase and α-d-galactosidases are shown to be responsible for the hydrolysis of β-l-arabinopyranosyl residues. The major plant sugar l-arabinose (l-Ara) has two different ring forms, l-arabinofuranose (l-Araf) and l-arabinopyranose (l-Arap). Although l-Ara mainly appears in the form of α-l-Araf residues in cell wall components, such as pectic α-1,3:1,5-arabinan, arabinoxylan, and arabinogalactan-proteins (AGPs), lesser amounts of it can also be found as β-l-Arap residues of AGPs. Even though AGPs are known to be rapidly metabolized, the enzymes acting on the β-l-Arap residues remain to be identified. In the present study, four enzymes, which we call β-l-ARAPASE (APSE) and α-GALACTOSIDASE 1 (AGAL1), AGAL2, and AGAL3, are identified as those enzymes that are likely to be responsible for the hydrolysis of the β-l-Arap residues in Arabidopsis thaliana. An Arabidopsis apse-1 mutant showed significant reduction in β-l-arabinopyranosidase activity, and an apse-1 agal3-1 double-mutant exhibited even less activity. The apse-1 and the double-mutants both had more β-l-Arap residues in the cell walls than wild-type plants. Recombinant APSE expressed in the yeast Pichia pastoris specifically hydrolyzed β-l-Arap residues and released l-Ara from gum arabic and larch arabinogalactan. The recombinant AGAL3 also showed weak β-l-arabinopyranosidase activity beside its strong α-galactosidase activity. It appears that the β-l-Arap residues of AGPs are hydrolysed mainly by APSE and partially by AGALs in Arabidopsis.
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影响因子：
5.6
作者：
Knoch E;Dilokpimol A;Geshi N
通讯作者：
Geshi N
影响因子：
7.2
作者：
Clough, SJ;Bent, AF
通讯作者：
Bent, AF
影响因子：
2.9
作者：
DYGERT, S;LI, LH;THOMA, JA
通讯作者：
THOMA, JA
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作者：
CHEUNG, AY;WANG, H;WU, HM
通讯作者：
WU, HM
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作者：
Konishi, Tomoyuki;Kotake, Toshihisa;Tsumuraya, Yoichi
通讯作者：
Tsumuraya, Yoichi