title: Improving special hydrolysis characterization into Talaromyces thermophilus F1208 xylanase by engineering of N-terminal extension and site-directed mutagenesis in C-terminal.
abstract: The purpose of this study was to gain insights into the hydrolysis characteristics of xylanase in producing xylo-oligosaccharides and to improve these by protein engineering. In this study, a hybrid enzyme (T-XynFM) was created from Talaromyces thermophilus F1208 xylanase (T-Xyn) by replacement of the N-terminal extension Phe1-Pro16 with Ala1-Gln8 and substitution of amino acid Phe193 (185) with Ser in the C-terminal. The enzyme showed optimum activity at 55°C and pH 6.5. Its residual activity was more than 55% after treatment at 50°C, pH 6.5 for 12h Km values of T-XynFM for beechwood xylan, birchwood xylan, and oat-spelt xylan were 10.31, 10.03, and 8.90mgmL-1, respectively. The enzyme displayed special hydrolysis characteristics: almost no xylose was produced on using xylotriose (X3), xylotetraose (X4), and xylopentaose as substrates. Moreover, over 60% X4 existed in hydrolyzed products of X3, indicating that T-XynFM possesses formidable transglycosylation properties.
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Beijing 100048, China; School of Food and Chemical Engineering, Beijing Technology and Business University, No. 33, Fucheng Road, Beijing 100048, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Beijing 100048, China; School of Food and Chemical Engineering, Beijing Technology and Business University, No. 33, Fucheng Road, Beijing 100048, China.
authors.forename: Baoguo
authors.initials: B
authors.lastname: Sun
authors.affiliation: School of Food and Chemical Engineering, Beijing Technology and Business University, No. 33, Fucheng Road, Beijing 100048, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Xiong
authors.affiliation: Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University (BTBU), Beijing 100048, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Teng
authors.affiliation: School of Food and Chemical Engineering, Beijing Technology and Business University, No. 33, Fucheng Road, Beijing 100048, China; Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University (BTBU), Beijing 100048, China.
authors.forename: Youqiang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Food and Chemical Engineering, Beijing Technology and Business University, No. 33, Fucheng Road, Beijing 100048, China.
authors.forename: Liangjun
authors.initials: L
authors.lastname: Li
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Beijing 100048, China; School of Food and Chemical Engineering, Beijing Technology and Business University, No. 33, Fucheng Road, Beijing 100048, China. Electronic address: lixt@btbu.edu.cn.
authors.forename: Xiuting
authors.initials: X
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism; D015202:Protein Engineering; D013379:Substrate Specificity; D032901:Talaromyces / Q000201:enzymology*; D013696:Temperature
chemical_list: D009844:Oligosaccharides; D043364:Endo-1,4-beta Xylanases
keywords: Hydrolysis; Protein engineering; Xylanase; Xylo-oligosaccharides