β-Galactosidase from Ginkgo biloba seeds active against β-galactose-containing N-glycans: Purification and characterization.
β-Galactosidase from Ginkgo biloba seeds active against β-galactose-containing N-glycans: Purification and characterization.
复制标题
来自银杏种子的 β-半乳糖苷酶对含有 β-半乳糖的 N-聚糖具有活性：纯化和表征。
DOI：
10.1080/09168451.2015.1034653
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
and Yoshinobu Kimura
中科院分区：
文献类型：
--
作者：
Md. Ziaur Rahman;Megumi Maeda;and Yoshinobu Kimura
在这项研究中，我们从银杏种子中纯化了一种酸性β-半乳糖苷酶（β-Gal 'ase Gb-1），纯度约为270倍。在非还原条件下，经凝胶过滤纯化的β-Gal酶Gb-1的分子量约为35 kDa， SDS-PAGE的分子量约为32 kDa。另一方面，在还原条件下，β-Gal 'ase Gb-1通过SDS-PAGE产生了分子量为16 kDa的单条带。32 kDa和16 kDa分子的末端氨基酸序列相同，鉴定为H-K-A-N-X-V-T-V-A-F-V-M-T-Q-H-，表明β-Gal 'ase Gb-1在体内可能具有同二聚体结构。以含有β-半乳糖残基的配合物型聚糖为底物时，β-Gal '酶Gb-1对β- 1-半乳糖残基表现出较强的活性，对β- 1-3 -半乳糖残基表现出较弱的活性，最适pH接近5.0。在此基础上，讨论了β-Gal酶Gb-1在植物复合物型聚糖降解中的作用。
In this study, we purified an acidic β-galactosidase to homogeneity fromGinkgo bilobaseeds (β-Gal’ase Gb-1) with approximately 270-fold purification. A molecular mass of the purified β-Gal’ase Gb-1 was estimated about 35 kDa by gel filtration and 32 kDa by SDS-PAGE under non-reducing condition, respectively. On the other hand, β-Gal’ase Gb-1 produced a single band with a molecular mass of 16 kDa by SDS-PAGE under reducing condition. TheN-terminal amino acid sequences of 32 kDa and 16 kDa molecules were the same and identified as H-K-A-N-X-V-T-V-A-F-V-M-T-Q-H-, suggesting that β-Gal’ase Gb-1 may function as a homodimeric structurein vivo. When complex-typeN-glycans containing β-galactosyl residues were used as substrates, β-Gal’ase Gb-1 showed substantial activity for β1-4 galactosyl residue and modest activity for β1-3 galactosyl residue with an optimum pH near 5.0. Based on these results, the involvement of β-Gal’ase Gb-1 in the degradation of plant complex-typeN-glycans is discussed.