Department of Plant Science and Techonology, Beijing University of Agriculture, Beijing 102206, China; State Key Laboratory for Agrobiotechnology and Department of Microbiology, China Agricultural University, Beijing 100193, China.
Department of Fungal Resource, Shandong Agricultural University, 61 Daizong Street, Tai'an, Shandong 271018, China.
Int J Biol Macromol. 2017 Nov;104(Pt A):576-583. doi: 10.1016/j.ijbiomac.2017.06.077. Epub 2017 Jun 19.
A 45-kDa monomeric acidic α-galactosidase with a specific activity of 193.12 units/mg was isolated from the fruiting bodies of Agaricus bisporus. Blast search of internal peptide sequences suggested that it is a member of GH family 27 and it is most similar to hypothetical protein AGABI2DRAFT_70106. The enzyme displayed maximal activity at pH 4.0 and 60°C, respectively. The enzyme remained stable within the pH range 2.0-9.0 but its activity was markedly suppressed in the presence of Cu, Hg, Fe and Ag ions. It displayed resistance to α-chymotrypsin and neutral protease. Moreover, it manifested degradative activity toward both oligosaccharides and polysaccharides. The enzyme manifested Km values of 0.30mM, 10.65mM and 19.21mM, toward pNPGal, stachyose and raffinose respectively. These results suggest that Agaricus bisporus α-galactosidase is a promising candidate for elimination of raffinose oligosaccharides (RFOs) in biotechnological applications.
从双孢蘑菇的子实体中分离得到一种分子量为 45kDa 的单体酸性α-半乳糖苷酶，比活为 193.12 单位/mg。内部肽序列的 Blast 搜索表明，它是 GH 家族 27 的成员，与假定蛋白 AGABI2DRAFT_70106 最相似。该酶在 pH4.0 和 60°C 时分别显示出最大活性。该酶在 pH2.0-9.0 范围内稳定，但在存在 Cu、Hg、Fe 和 Ag 离子时其活性明显受到抑制。它对α-糜蛋白酶和中性蛋白酶具有抗性。此外，它对寡糖和多糖均表现出降解活性。该酶对 pNPGal、棉子糖和棉子糖的 Km 值分别为 0.30mM、10.65mM 和 19.21mM。这些结果表明，双孢蘑菇α-半乳糖苷酶是生物技术应用中去除棉子糖寡糖（RFOs）的有前途的候选酶。
