title: Overexpression of D-psicose 3-epimerase from Ruminococcus sp. in Escherichia coli and its potential application in D-psicose production.
abstract: The D-psicose 3-epimerase (DPE) gene from Ruminococcus sp. was cloned and overexpressed in Escherichia coli. The recombinant protein was purified and characterized. It was optimally active at pH 7.5-8.0 and 60 °C. Activity was not dependent on the presence of metal ions; however, it became more thermostable with added Mn(2+). The K (m) of the enzyme for D-psicose (48 mM) was lower than that for D-tagatose (230 mM), suggesting that D-psicose is the optimum substrate. More importantly, the thermostability of the novel DPE from Ruminococcus is the strongest among all of the D-psicose and D-tagatose 3-epimerases and may be suitable for the industrial production of D-psicose from fructose.
authors: National Engineering Laboratory for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Xiqi Road 32#, Tianjin Airport Economic Area, Tianjin 300308, People's Republic of China.
authors: Yueming
authors: Y
authors: Zhu
authors: Yan
authors: Y
authors: Men
authors: Wei
authors: W
authors: Bai
authors: Xiaobo
authors: X
authors: Li
authors: Lili
authors: L
authors: Zhang
authors: Yuanxia
authors: Y
authors: Sun
authors: Yanhe
authors: Y
authors: Ma
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002238:Carbohydrate Epimerases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005632:Fructose / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008670:Metals; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D045857:Ruminococcus / Q000201:enzymology* / Q000235:genetics; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D008670:Metals; D011994:Recombinant Proteins; C003243:psicose; D005632:Fructose; D002238:Carbohydrate Epimerases