Guo Yunhai, He Hongxuan
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.
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Fish Shellfish Immunol. 2014 Aug;39(2):321-5. doi: 10.1016/j.fsi.2014.05.029. Epub 2014 May 29.
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.
淡水螺尖膀胱螺被认为是一种重要的入侵物种和医学软体动物。野外调查表明，这种螺在污染水体中比其他螺存活得更好。为了解尖膀胱螺的免疫机制，已通过细菌攻击构建了抑制性消减杂交肝胰腺cDNA文库。在本研究中，通过EST和RACE技术从尖膀胱螺中鉴定出一种新型鹅型溶菌酶（PALysG）的全长cDNA。其保守结构域与其他软体动物g型溶菌酶具有高度同源性，包括SLT结构域、底物结合位点、催化残基、三个α螺旋结构和六个软体动物特有的半胱氨酸。同时，PALysG是腹足纲中鹅型溶菌酶的首次记录。实时PCR表明，PALysG mRNA在肝胰腺中8-48小时内显著高水平表达。PALysG重组蛋白对其他生物显示出g型溶菌酶对溶壁微球菌的裂解活性。
