title: Purification and characterization of oxygen-inducible haem catalase from oxygen-tolerant Bifidobacterium asteroides.
abstract: Bifidobacterium asteroides, originally isolated from honeybee intestine, was found to grow under 20% O(2) conditions in liquid shaking culture using MRS broth. Catalase activity was detected only in cells that were exposed to O(2) and grown in medium containing a haem source, and these cells showed higher viability on exposure to H(2)O(2). Passage through multiple column chromatography steps enabled purification of the active protein, which was identified as a homologue of haem catalase on the basis of its N-terminal sequence. The enzyme is a homodimer composed of a subunit with a molecular mass of 55 kDa, and the absorption spectrum shows the typical profile of bacterial haem catalase. A gene encoding haem catalase, which has an amino acid sequence coinciding with the N-terminal amino acid sequence of the purified protein, was found in the draft genome sequence data of B. asteroides. Expression of the katA gene was induced in response to O(2) exposure. The haem catalase from B. asteroides shows about 70-80% identity with those from lactobacilli and other lactic acid bacteria, and no homologues were found in other bifidobacterial genomes.
authors.affiliation: Department of Biosciences, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Kyohei
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Department of Biosciences, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Itaru
authors.initials: I
authors.lastname: Maekawa
authors.affiliation: Department of Biosciences, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Kunifusa
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Department of Biosciences, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Ijyuin
authors.affiliation: Genome Research Center, NODAI Research Institute, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shiwa
authors.affiliation: Department of Biosciences, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Ippei
authors.initials: I
authors.lastname: Suzuki
authors.affiliation: Department of Biosciences, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Youichi
authors.initials: Y
authors.lastname: Niimura
authors.affiliation: Department of Biosciences, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawasaki
mesh_terms: D001644:Bifidobacterium / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D002374:Catalase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D006418:Heme / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000633:toxicity; D050296:Microbial Viability / Q000187:drug effects; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D055503:Protein Multimerization; D021122:Protein Subunits; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013057:Spectrum Analysis; D015533:Transcriptional Activation
chemical_list: D004269:DNA, Bacterial; D021122:Protein Subunits; D006418:Heme; D006861:Hydrogen Peroxide; D002374:Catalase; D010100:Oxygen