Characterization of a Novel Maltose-Forming α-Amylase from Lactobacillus plantarum subsp. plantarum ST-III

详细信息    查看全文

• 作者：Hye-Yeon Jeon ; Na-Ri Kim ; Hye-Won Lee ; Hye-Jeong Choi ; Woo-Jae Choung ; Ye-Seul Koo ; Dam-Seul Ko ; Jae-Hoon Shim
• 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：2307-2314
• 全文大小：491K
• ISSN：1520-5118

文摘

A novel maltose (G2)-forming α-amylase from Lactobacillus plantarum subsp. plantarum ST-III was expressed in Escherichia coli and characterized. Analysis of conserved amino acid sequence alignments showed that L. plantarum maltose-producing α-amylase (LpMA) belongs to glycoside hydrolase family 13. The recombinant enzyme (LpMA) was a novel G2-producing α-amylase. The properties of purified LpMA were investigated following enzyme purification. LpMA exhibited optimal activity at 30 °C and pH 3.0. It produced only G2 from the hydrolysis of various substrates, including maltotriose (G3), maltopentaose (G5), maltosyl β-cyclodextrin (G2-β-CD), amylose, amylopectin, and starch. However, LpMA was unable to hydrolyze cyclodextrins. Reaction pattern analysis using 4-nitrophenyl-α-d-maltopentaoside (pNPG5) demonstrated that LpMA hydrolyzed pNPG5 from the nonreducing end, indicating that LpMA is an exotype α-amylase. Kinetic analysis revealed that LpMA had the highest catalytic efficiency (k_cat/K_m ratio) toward G2-β-CD. Compared with β-amylase, a well-known G2-producing enzyme, LpMA produced G2 more efficiently from liquefied corn starch due to its ability to hydrolyze G3.