Isolation and characterization of a novel α-glucosidase with transglycosylation activity from Arthrobacter sp. DL001
作者:Kun Zhou、Hong-wei Luan、Ying Hu、Guang-bo Ge、Xing-bao Liu、Xiao-chi Ma、Jie Hou、Xiu-li Wang、Ling Yang
DOI:10.1016/j.molcatb.2012.04.016
日期:2012.8
A strain of Arthrobacter sp. DL001 with high transglycosylation activity was successfully isolated from the Yellow Sea of China. To purify the extracellular enzyme responsible for transglycosylation, a four-step protocol was adopted and the enzyme with electrophoretical purity was obtained. The purified enzyme has a molecular mass of 210 kDa and displays a narrow hydrolysis specificity towards alpha-1,4-glucosidic bond. Its hydrolytic activity was identified as decreasing in the order of maltotriose > panose > maltose. Only 3.61% maltose activity occurs when p-nitrophenyl alpha-D-glycopyranoside serves as a substrate, suggesting that this enzyme belongs to the type II alpha-glucosidase. In addition, the enzyme was able to transfer glucosyl groups from the donors containing alpha-1,4-glucosidic bond specific to glucosides, xylosides and alkyl alcohols in alpha-1,4- or alpha-1,6-manners. A decreased order of activity was observed when maltose, maltotriose, panose, beta-cyclodextrin and soluble starch served as glycosyl donors, respectively. When maltose was utilized as a donor and a series of p-nitrophenyl-glycosides as acceptors, the glucosidase was capable of transferring glucosyl groups to p-nitrophenyl-glucosides and p-nitrophenyl-xylosides in alpha-1,4- or alpha-1,6-manners. The yields of p-nitrophenyl-oligosaccharides could reach 42-60% in 2 h. When a series of alkyl alcohols were utilized as acceptors, the enzyme exhibited its transglycosylation activities not only to the primary alcohols but also to the secondary alcohols with carbon chain length 1-4. Therefore, all the results indicated that the purified alpha-glucosidase present a useful tool for the biosynthesis of oligosaccharides and alkyl glucosides. (C) 2012 Elsevier B.V. All rights reserved.