title: Purification, characterization, and gene sequencing of a catalase from an alkali- and halo-tolerant bacterium, Halomonas sp. SK1.
abstract: An alkali- and halo-tolerant bacterium with high catalase activity was isolated and identified as a new species of the genus Halomonas. Its catalase (HktA) was simply purified by two steps of liquid chromatography. A 71.4% yield of the catalase was obtained with 97% purity on SDS-PAGE. The specific activity of HktA (57,900 U/mg protein) was two times higher than that of bovine liver catalase. The purified enzyme is inhibited by KCN, NH2OH, NaN3, and 3-amino-1,2,4-triazole, active at pH 5.0-11.0, thermo-sensitive, and KCl-tolerant. HktA is suggested to be a typical catalase, a homotetrameric protein containing heme groups in the active sites. The nucleotide sequence of the catalase gene (hktA) comprises 1,530 bp, encoding a protein of 509 amino acid residues. The deduced amino acid sequence of the hktA shares 99% identity with that of Vibrio rumoiensis S-1T.
authors.affiliation: Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, Kiryu, Japan.
authors.forename: Krisana
authors.initials: K
authors.lastname: Phucharoen
authors.forename: Kiichi
authors.initials: K
authors.lastname: Hoshino
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Takenaka
authors.forename: Takao
authors.initials: T
authors.lastname: Shinozawa
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002374:Catalase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D020632:Halomonas / Q000201:enzymology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D002374:Catalase