title: Biochemical characterization of a thermophilic cellobiose 2-epimerase from a thermohalophilic bacterium, Rhodothermus marinus JCM9785.
abstract: Cellobiose 2-epimerase (CE) reversibly converts glucose residue to mannose residue at the reducing end of β-1,4-linked oligosaccharides. It efficiently produces epilactose carrying prebiotic properties from lactose, but the utilization of known CEs is limited due to thermolability. We focused on thermoholophilic Rhodothermus marinus JCM9785 as a CE producer, since a CE-like gene was found in the genome of R. marinus DSM4252. CE activity was detected in the cell extract of R. marinus JCM9785. The deduced amino acid sequence of the CE gene from R. marinus JCM9785 (RmCE) was 94.2% identical to that from R. marinus DSM4252. The N-terminal amino acid sequence and tryptic peptide masses of the native enzyme matched those of RmCE. The recombinant RmCE was most active at 80 °C at pH 6.3, and stable in a range of pH 3.2-10.8 and below 80 °C. In contrast to other CEs, RmCE demonstrated higher preference for lactose over cellobiose.
authors: Nihon Shokuhin Kako Co, Ltd, Fuji, Shizuoka, Japan.
authors: Teruyo
authors: T
authors: Ojima
authors: Wataru
authors: W
authors: Saburi
authors: Hiroki
authors: H
authors: Sato
authors: Takeshi
authors: T
authors: Yamamoto
authors: Haruhide
authors: H
authors: Mori
authors: Hirokazu
authors: H
authors: Matsui
mesh_terms: D000595:Amino Acid Sequence; D002475:Cellobiose / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D003001:Cloning, Molecular; D004187:Disaccharides / Q000378:metabolism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D019998:Racemases and Epimerases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000737:chemistry; D045245:Rhodothermus / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004187:Disaccharides; D011994:Recombinant Proteins; D002475:Cellobiose; C047464:epilactose; D019998:Racemases and Epimerases