title: Presence and characterization of multiple mantle lysozymes in the Pacific oyster, Crassostrea gigas.
abstract: Mantle tissue extracts from the Pacific oyster, Crassostrea gigas, exhibited anti-Gram-positive bacterial and lysozyme activities over a wide pH range, suggesting that multiple defensive mantle lysozymes were present. Degenerated reverse-transcription PCR detected the expression of two mantle lysozymes, CGL-1 and a novel lysozyme CGL-3, confirming the presence of multiple lysozymes in the mantle. Since CGL-3 is a cognate protein of the digestive lysozyme CGL-2, it is assumed that CGL-3 has evolved specifically a defensive function. Functional assays using recombinant CGL-1 and CGL-3 suggested that CGL-1 and CGL-3 play a major defensive role in the mantle tissue, and that they are responsible for lysozyme activity under different pH, ionic strength and temperature conditions. Based on these observations, we conclude that multiple mantle lysozymes in the Pacific oyster are better for host-defense under broader conditions than a single lysozyme.
authors.affiliation: Laboratory of Aquacultural Biology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori Amamiya-machi, Aoba-ku, Sendai, Miyagi 981-8555, Japan. nitoh@bios.tohoku.ac.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Itoh
authors.forename: Yuki
authors.initials: Y
authors.lastname: Okada
authors.forename: Keisuke G
authors.initials: KG
authors.lastname: Takahashi
authors.forename: Makoto
authors.initials: M
authors.lastname: Osada
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D049896:Crassostrea / Q000201:enzymology / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000276:immunology; D006094:Gram-Positive Bacteria / Q000276:immunology; D007527:Isoenzymes / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D009113:Muramidase / Q000235:genetics / Q000276:immunology*; D010802:Phylogeny; D010843:Pichia / Q000235:genetics; D012313:RNA / Q000737:chemistry / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D007527:Isoenzymes; D011994:Recombinant Proteins; D012313:RNA; D009113:Muramidase