Characterization of a recombinant L-fucose isomerase from Caldicellulosiruptor saccharolyticus that isomerizes L-fucose, D-arabinose, D-altrose, and L-galactose.
A recombinant L-fucose isomerase from Caldicellulosiruptor saccharolyticus was purified as a single 68 kDa band with an activity of 76 U mg(-1). The molecular mass of the native enzyme was 204 kDa as a trimer. The maximum activity for L-fucose isomerization was at pH 7 and 75 degrees C in the presence of 1 mM Mn(2+). Its half-life at 70 degrees C was 6.1 h. For aldose substrates, the enzyme displayed activity in decreasing order for L-fucose, with a k (cat) of 11,910 min(-1) and a K (m) of 140 mM, D-arabinose, D-altrose, and L-galactose. These aldoses were converted to the ketoses L-fuculose, D-ribulose, D-psicose, and L-tagatose, respectively, with 24, 24, 85, 55% conversion yields after 3 h.
Ju
Yo-Han
YH
Department of Bioscience and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, South Korea.
Oh
Deok-Kun
DK
D019747:Aldose-Ketose Isomerases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001089:Arabinose / Q000737:chemistry*; D004789:Enzyme Activation; D005643:Fucose / Q000737:chemistry*; D005690:Galactose / Q000737:chemistry*; D007536:Isomerism; D011994:Recombinant Proteins / Q000737:chemistry* / Q000378:metabolism; D046950:Thermoanaerobacterium / Q000201:enzymology* / Q000235:genetics
D011994:Recombinant Proteins; D005643:Fucose; D001089:Arabinose; D019747:Aldose-Ketose Isomerases; C019714:D-arabinose isomerase; D005690:Galactose