title: Identification and characterization of a goose-type lysozyme from sewage snail Physa acuta.
abstract: Freshwater snail Physa acuta has been considered as an important invasive species and medical mollusc. Field investigation has shown that this snail could survive better than other snails in polluted water bodies. To understand the immune mechanisms of P. acuta, suppression subtractive hybridization hepatopancreas cDNA library has been constructed with bacterial challenge. In this study, a full-length cDNA of a novel goose-type lysozyme (PALysG) has been identified from P. acuta by EST and RACE technique. The conservative structure domains share high homology with other molluscan g-type lysozymes including the SLT domain, the substrate binding sites, the catalytic residues, three alpha-helices structures and six molluscan specific cysteines. Meanwhile, PALysG is the first record of goose-type lysozyme in Gastropoda. Real-time PCR indicated that PALysG mRNA had been expressed significantly at high levels in hepatopancreas for 8-48 h. PALysG recombinant protein displayed the lytic activity of g-type lysozyme with other organisms against Micrococcus lysodikicus.
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai 200025, China; Key Laboratory of Parasite and Vector Biology of the Chinese Ministry of Health, WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
authors.forename: Yunhai
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: hehx@ioz.ac.cn.
authors.forename: Hongxuan
authors.initials: H
authors.lastname: He
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D020224:Expressed Sequence Tags; D043143:Hepatopancreas / Q000378:metabolism; D058865:Introduced Species; D008837:Micrococcus / Q000276:immunology*; D008969:Molecular Sequence Data; D009113:Muramidase / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012908:Snails / Q000201:enzymology* / Q000276:immunology* / Q000382:microbiology; D066251:Subtractive Hybridization Techniques
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D009113:Muramidase
keywords: Antimicrobial activities; Freshwater snail; Goose-type lysozyme; Physa acuta; Real-time PCR