title: Leuconostoc citreum SK24.002 glucansucrase: Biochemical characterisation and de novo synthesis of α-glucan.
abstract: The cell-associated glucansucrase from Leuconostoc citreum SK24.002 was isolated, purified, characterized and used for de novo synthesis of α-glucan and acceptor-products. The final specific glucansucrase activity was 1.4U/mg protein with 13.2-fold purification. The obtained glucansucrase had a molecular weight of 186kDa,Tm of 61.7 °C and △H of 176.7kJ/mol. The enzyme showed maximum activity at pH 5.0-6.0 and 45°C. The enzyme activity was enhanced by Ca(2+), Mn(2+) or Co(2+) ions, whereas the activity decreased as the methanol, ethanol, n-butanol, DMSO or isopropanol concentration increased. The chemical inhibitors including BD, DTNB, EDC or NBS also significantly inhibited enzyme activity. Km, Vmax and kcat of glucansucrase were 10.9mM, 3.6U/mg and 306.6 1/s, respectively. For de novo synthesis from sucrose, α-glucan polymer with molecular weight of 1.5×10(7)g/mol and maltose acceptor products (trisaccharide, tetrasaccharide and pentasaccharide) were obtained by glucansucrase via glucosyltransfer reactions, respectively.
authors.affiliation: State Key Laboratory of Food Science & Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China.
authors.forename: Liping
authors.initials: L
authors.lastname: Song
authors.affiliation: State Key Laboratory of Food Science & Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China. Electronic address: miaoming@jiangnan.edu.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Miao
authors.affiliation: State Key Laboratory of Food Science & Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Food Science & Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Food Science & Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China; Guelph Food Research Centre, Agriculture and Agri-Food Canada, 93 Stone Road West, Guelph, ON N1G 5C9, Canada.
authors.forename: Steve W
authors.initials: SW
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Food Science & Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
mesh_terms: D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D005511:Food Handling; D005936:Glucans / Q000096:biosynthesis*; D016695:Glycosyltransferases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007934:Leuconostoc / Q000201:enzymology*; D008320:Maltose / Q000096:biosynthesis; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D012997:Solvents / Q000494:pharmacology; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D005936:Glucans; D008670:Metals; D012997:Solvents; D008320:Maltose; D016695:Glycosyltransferases; C033837:alternansucrase
keywords: Characterization; De novo synthesis; L. citreum SK24.002 glucansucrase