1. A Shinella β- N-acetylglucosaminidase of glycoside hydrolase family 20 displays novel biochemical and molecular characteristics.
- Author
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Zhou, Junpei, Song, Zhifeng, Zhang, Rui, Chen, Caihong, Wu, Qian, Li, Junjun, Tang, Xianghua, Xu, Bo, Ding, Junmei, Han, Nanyu, and Huang, Zunxi
- Subjects
GLYCOSIDASES ,ESCHERICHIA coli ,GENE expression ,CHITIN biodegradation ,BIOCONVERSION - Abstract
β- N-Acetylglucosaminidases (GlcNAcases) are important for many biological functions and industrial applications. In this study, a glycoside hydrolase family 20 GlcNAcase from Shinella sp. JB10 was expressed in Escherichia coli BL21 (DE3). Compared to many GlcNAcases, the purified recombinant enzyme (rJB10Nag) exhibited a higher specificity activity (538.8 µmol min mg) or V (1030.0 ± 82.1 µmol min mg) toward p-nitrophenyl β- N-acetylglucosaminide and N, N′-diacetylchitobiose (specificity activity of 35.4 µmol min mg) and a higher N-acetylglucosaminide tolerance (approximately 50% activity in 70.0 mM N-acetylglucosaminide). The degree of synergy on enzymatic degradation of chitin by a commercial chitinase and rJB10Nag was as high as 2.35. The enzyme was tolerant to most salts, especially 3.0-15.0% (w/v) NaCl and KCl. These biochemical characteristics make the JB10 GlcNAcase a candidate for use in many potential applications, including processing marine materials and the bioconversion of chitin waste. Furthermore, the enzyme has the highest proportions of alanine (16.5%), glycine (10.5%), and random coils (48.8%) with the lowest proportion of α-helices (24.9%) among experimentally characterized GH 20 GlcNAcases from other organisms. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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