title: Characterization of a recombinant thermostable D-lyxose isomerase from Dictyoglomus turgidum that produces D-lyxose from D-xylulose.
abstract: A putative D-lyxose isomerase from Dictyoglomus turgidum was purified with a specific activity of 19 U/mg for D-lyxose isomerization by heat treatment and affinity chromatography. The native enzyme was estimated as a 42 kDa dimer by gel-filtration chromatography. The activity of the enzyme was highest for D-lyxose, suggesting that it is a D-lyxose isomerase. The maximum activity of the enzyme was at pH 7.5 and 75°C in the presence of 0.5 mM Co(2+), with a half-life of 108 min, K(m) of 39 mM, and k(cat) of 3,570 1/min. The enzyme is the most thermostable D-lyxose isomerase among those characterized to date. It converted 500 g D-xylulose/l to 380 g D-lyxose/l after 2 h. This is the highest concentration and productivity of D-lyxose reported thus far.
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul, South Korea.
authors.forename: Jin-Geun
authors.initials: JG
authors.lastname: Choi
authors.forename: Seung-Hye
authors.initials: SH
authors.lastname: Hong
authors.forename: Yeong-Su
authors.initials: YS
authors.lastname: Kim
authors.forename: Kyoung-Rok
authors.initials: KR
authors.lastname: Kim
authors.forename: Deok-Kun
authors.initials: DK
authors.lastname: Oh
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D001419:Bacteria / Q000201:enzymology*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D003035:Cobalt / Q000378:metabolism; D003067:Coenzymes / Q000378:metabolism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D010429:Pentoses / Q000378:metabolism*; D055503:Protein Multimerization; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013696:Temperature; D014996:Xylulose / Q000378:metabolism*
chemical_list: D003067:Coenzymes; D010429:Pentoses; D011994:Recombinant Proteins; D003035:Cobalt; D014996:Xylulose; C043333:lyxose; D019747:Aldose-Ketose Isomerases; C021525:D-lyxose ketol-isomerase