Characterization of a Glycoside Hydrolase Family 27 α-Galactosidase from Pontibacter Reveals Its Novel Salt–Protease Tolerance and Transglycosylation Activity

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• 作者：Junpei Zhou ; Yu Liu ; Qian Lu ; Rui Zhang ; Qian Wu ; Chunyan Li ; Junjun Li ; Xianghua Tang ; Bo Xu ; Junmei Ding ; Nanyu Han ; Zunxi Huang
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2016
• 出版时间：March 23, 2016
• 年：2016
• 卷：64
• 期：11
• 页码：2315-2324
• 全文大小：511K
• ISSN：1520-5118

文摘

α-Galactosidases are of great interest in various applications. A glycoside hydrolase family 27 α-galactosidase was cloned from Pontibacter sp. harbored in a saline soil and expressed in Escherichia coli. The purified recombinant enzyme (rAgaAHJ8) was little or not affected by 3.5–30.0% (w/v) NaCl, 10.0–100.0 mM Pb(CH₃COO)₂, 10.0–60.0 mM ZnSO₄, or 8.3–100.0 mg mL^–1 trypsin and by most metal ions and chemical reagents at 1.0 and 10.0 mM concentrations. The degree of synergy on enzymatic degradation of locust bean gum and guar gum by an endomannanase and rAgaAHJ8 was 1.22–1.54. In the presence of trypsin, the amount of reducing sugars released from soybean milk treated by rAgaAHJ8 was approximately 3.8-fold compared with that treated by a commercial α-galactosidase. rAgaAHJ8 showed transglycosylation activity when using sucrose, raffinose, and 3-methyl-1-butanol as the acceptors. Furthermore, potential factors for salt adaptation of the enzyme were presumed.