Role of two α-L-arabinofuranosidases in arabinoxylan degradation and characteristics of the encoding genes from shochu koji molds, Aspergillus kawachii and Aspergillus awamori
Role of two α-L-arabinofuranosidases in arabinoxylan degradation and characteristics of the encoding genes from shochu koji molds, Aspergillus kawachii and Aspergillus awamori
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DOI：
10.1016/s1389-1723(03)80187-1
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发表时间：
2003-09-01
影响因子：
2.8
通讯作者：
Matsuzawa, H
中科院分区：
文献类型：
--
作者：
Koseki, T;Okuda, M;Matsuzawa, H
从白曲霉（Aspergillus kawachii）中纯化并表征了两种不同的α-L-阿拉伯呋喃糖苷酶。这两种酶与木聚糖酶协同降解阿拉伯木聚糖，并导致阿魏酸酯酶释放阿魏酸的量增加。这两种酶都是嗜酸性和酸稳定的酶，其最适pH为4.0，在pH 3.0-7.0范围内稳定。该酶的最适pH和pH稳定性与泡盛曲霉相似。这些结果表明，α-L-阿拉伯呋喃糖苷酶有助于提高谷物利用率和烧酒酿造中香气的形成。两个不同的基因编码的α-L-阿拉伯呋喃糖苷酶从A。kawachii，命名为AkabfA和AkabfB; awamori基因，命名为AwabfA和AwabfB。AkabfA和AwabfA的序列之间的差异仅为一个核苷酸，导致序列中的氨基酸差异，并且酶被分配到糖苷水解酶家族51。另一方面，AkabfB和AwabfB的序列之间以及它们的编码蛋白之间的差异分别为两个核苷酸和一个氨基酸残基，并且将酶分配到糖苷水解酶家族54。比较了A. kawachii、川内拟步行虫A. awamori和A.尼日尔，分析了A. kawachii和A. awamori与A.尼日尔和其他国家。北方分析表明，AkabfB的转录大于AkabfA在L-阿拉伯糖醇和L-阿拉伯糖的存在下，和这两个基因的转录不诱导在蔗糖和葡萄糖的存在下。
Two different alpha-L-arabinofuranosidases from Aspergillus kawachii were purified and characterized. The two enzymes acted synergically with xylanase in the degradation of arabinoxylan and resulted in an increase in the amount of ferulic acid release by feruloyl esterase. Both enzymes were acidophilic and acid stable enzymes which had an optimum pH of 4.0 and were stable at pH 3.0-7.0. The general properties of the enzymes including pH optima and pH stability were similar to those of Aspergillus awamori. These results suggest that the alpha-L-arabinofuranosidases contribute to an increase in cereal utilization and formation of aroma in shochu brewing. Two different genes encoding alpha-L-arabinofuranosidases from A. kawachii, designated as AkabfA and AkabfB, and those from A. awamori, designated as AwabfA and AwabfB, were also cloned and characterized. The difference between the sequences of AkabfA and AwabfA was only one nucleotide, resulting in an amino acid difference in the sequence, and the enzymes were assigned to family 51 of glycoside hydrolases. On the other hand, the differences between the sequences of AkabfB and AwabfB and between their encoding proteins were two nucleotides and one amino acid residue, respectively, and the enzymes were assigned to family 54 of glycoside hydrolases. On comparison of the abfA and abfB genes among A. kawachii, A. awamori, and A. niger, the relationship between the two genes for A. kawachii and A. awamori was much closer than those between A. niger and the others. Northern analyses showed that transcription of AkabfB was greater than that of AkabfA in the presence of L-arabitol and L-arabinose, and that transcriptions of both genes were not induced in the presence of sucrose and glucose.