title: Heterologous expression and biochemical characterization of glucose isomerase from Thermobifida fusca.
abstract: Glucose isomerase (GIase) catalyzes the isomerization of D-glucose to D-fructose. The GIase from Thermobifida fusca WSH03-11 was expressed in Escherichia coli BL21(DE3), and the purified enzyme took the form of a tetramer in solution and displayed a pI value of 5.05. The temperature optimum of GIase was 80 °C and its half life was about 2 h at 80 °C or 15 h at 70 °C. The pH optimum of GIase was 10 and the enzyme retained 95 % activity over the pH range of 5-10 after incubating at 4 °C for 24 h. Kinetic studies showed that the K m and K cat values of the enzyme are 197 mM and 1,688 min(-1), respectively. The maximum conversion yield of glucose (45 %, w/v) to fructose of the enzyme was 53 % at pH 7.5 and 70 °C. The present study provides the basis for the industrial application of recombinant T. fusca GIase in the production of high fructose syrup.
authors: State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Ave., Wuxi, 214122, People's Republic of China.
authors: Hui
authors: H
authors: Deng
authors: Sheng
authors: S
authors: Chen
authors: Dan
authors: D
authors: Wu
authors: Jian
authors: J
authors: Chen
authors: Jing
authors: J
authors: Wu
mesh_terms: D000192:Actinomycetales / Q000201:enzymology / Q000235:genetics; D019747:Aldose-Ketose Isomerases / Q000096:biosynthesis / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D011994:Recombinant Proteins
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase