title: Cloning, characterization and tissue expression of disk abalone (Haliotis discus discus) catalase.
abstract: Catalase is an antioxidant enzyme that plays a significant role in protection against oxidative stress by detoxification of hydrogen peroxide (H2O2). A gene coding for a putative catalase was isolated from the disk abalone (Haliotis discus discus) cDNA library and denoted as Ab-catalase. The full-length (2864 bp) Ab-catalase cDNA contained 1,503 bp open reading frame (ORF), encoding 501 amino acid residues with 56 kDa predicted molecular weight. The deduced amino acid sequence of Ab-catalase has characteristic features of catalase family such as catalytic site motif (61FNRERIPERVVHAKGAG77), heme-ligand signature motif (351RLYSYSDT358), NADPH and heme binding residues. Phylogenetic and pairwise identity results indicated that Ab-catalase is more similar to scallop (Chlamys farreri) catalase with 80% amino acid identity except for other reported disk abalone catalase sequences. Constitutive Ab-catalase expression was detected in gill, mantle, gonad, hemocytes, abductor muscle and digestive tract in tissue specific manner. Ab-catalase mRNA was up-regulated in gill and digestive tract tissues for the first 3h post injection of H2O2, showing the inducible ability of abalone catalase against oxidative stress generated by H2O2. The purified recombinant catalase showed 30,000 U/mg enzymatic activity against H2O2 and biochemical properties of higher thermal stability and broad spectrum of pH. Our results suggest that abalone catalase may play an important role in regulating oxidative stress by scavenging H2O2.
authors.affiliation: Department of Marine Biotechnology, Cheju National University, 66 Jejudaehakno, Jeju 690-756, Republic of Korea.
authors.forename: Prashani Mudika
authors.initials: PM
authors.lastname: Ekanayake
authors.forename: Mahanama
authors.initials: M
authors.lastname: De Zoysa
authors.forename: Hyun-Sil
authors.initials: HS
authors.lastname: Kang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wan
authors.forename: Youngheun
authors.initials: Y
authors.lastname: Jee
authors.forename: Youn-Ho
authors.initials: YH
authors.lastname: Lee
authors.forename: Sang-Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Jehee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002374:Catalase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D049851:Gastropoda / Q000201:enzymology* / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D016877:Oxidants / Q000494:pharmacology; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013696:Temperature
chemical_list: D016877:Oxidants; D011994:Recombinant Proteins; D006861:Hydrogen Peroxide; D002374:Catalase