title: A Neutral Thermostable β-1,4-Glucanase from Humicola insolens Y1 with Potential for Applications in Various Industries.
abstract: We cloned a new glycoside hydrolase family 6 gene, Hicel6C, from the thermophilic fungus Humicola insolens Y1 and expressed it in Pichia pastoris. Using barley β-glucan as a substrate, recombinant HiCel6C protein exhibited neutral pH (6.5) and high temperature (70°C) optima. Distinct from most reported acidic fungal endo-β-1,4-glucanases, HiCel6C was alkali-tolerant, retaining greater than 98.0, 61.2, and 27.6% of peak activity at pH 8.0, 9.0, and 10.0, respectively, and exhibited good stability over a wide pH range (pH 5.0-11.0) and at temperatures up to 60°C. The Km and Vmax values of HiCel6C for barley β-glucan were 1.29 mg/mL and 752 μmol/min·mg, respectively. HiCel6C was strictly specific for the β-1,4-glucoside linkage exhibiting activity toward barley β-glucan, lichenan, and carboxy methylcellulose sodium salt (CMC-Na), but not toward laminarin (1,3-β-glucan). HiCel6C cleaved the internal glycosidic linkages of cellooligosaccharides randomly and thus represents an endo-cleaving enzyme. The predominant product of polysaccharide hydrolysis by HiCel6C was cellobiose, suggesting that it functions by an endo-processive mechanism. The favorable properties of HiCel6C make it a good candidate for basic research and for applications in the textile and brewing industries.
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Xu
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Jinyang
authors.initials: J
authors.lastname: Li
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Huoqing
authors.initials: H
authors.lastname: Huang
authors.affiliation: Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Pengjun
authors.initials: P
authors.lastname: Shi
authors.affiliation: Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Huiying
authors.initials: H
authors.lastname: Luo
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Yunliu
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yao
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology* / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004789:Enzyme Activation; D004795:Enzyme Stability; D015870:Gene Expression; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D010843:Pichia / Q000235:genetics; D011994:Recombinant Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity
chemical_list: D018076:DNA, Complementary; D011994:Recombinant Proteins; D006026:Glycoside Hydrolases