Molecular characterization and antibacterial activity of a phage‐type lysozyme from the Manila clam, Ruditapes philippinarum
Molecular characterization and antibacterial activity of a phage‐type lysozyme from the Manila clam, Ruditapes philippinarum
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DOI：
10.1016/j.fsi.2017.03.051
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发表时间：
2017-06
影响因子：
4.7
通讯作者：
Dinglong Yang;Qing Wang;Lizhu Chen;Yongliang Liu;Ruiwen Cao;Huifeng Wu;Fei Li;Chenglong Ji
中科院分区：
文献类型：
--
作者：
Dinglong Yang;Qing Wang;Lizhu Chen;Yongliang Liu;Ruiwen Cao;Huifeng Wu;Fei Li;Chenglong Ji
从菲律宾蛤仔（Ruditapes philippinarum）中克隆了一种噬菌体型溶菌酶，命名为RpPLYZ。RpPLYZ的cDNA全长为699 bp，开放阅读框（ORF）为534 bp，编码177个氨基酸，分子量为19.6 kDa，等电点为9.05。多重序列比对和系统发育分析表明，RpPLYZ是噬菌体型溶菌酶家族的一个新成员。发现RpPLYZ的mRNA转录本在广泛的组织中组成型表达，并且主要在血细胞和外套膜中。在鳗弧菌攻击后6、24、48和72 h，血细胞中RpPLYZ mRNA的相对表达量显著上调。重组RpPLYZ（rRpPLYZ）对阴沟肠杆菌和金黄色葡萄球菌具有较高的活性，对产气肠杆菌和鳗弧菌的活性较低。此外，确定rRpPLYZ活性的最佳pH、温度和离子强度分别为5.5、50 °C和5mM。这些结果表明，RpPLYZ是噬菌体型溶菌酶家族的一员，可能在抵抗细菌入侵的免疫反应中起重要作用。
A phage-type lysozyme, designed as RpPLYZ, was cloned and characterized from the clamRuditapes philippinarum. The full-length cDNA of RpPLYZ was of 699 bp with an open reading frame (ORF) of 534 bp, encoding a polypeptide of 177-amino acid with a calculated molecular mass of 19.6 kDa and an isoelectric point of 9.05. Multiple alignments and phylogenetic analysis strongly suggested that RpPLYZ was a new member of the phage-type lysozyme family. The mRNA transcript of RpPLYZ was found to be constitutively expressed in a wide range of tissues and mainly in hemocytes and mantle. The relative expression of RpPLYZ mRNA in hemocytes was significantly up-regulated at 6, 24, 48 and 72 h afterVibrio anguillarumchallenge. The recombinant RpPLYZ (rRpPLYZ) showed high activity againstEntherobacter cloacaeandStaphyloccocus aureus, and less effective towardsEntherobacter aerogenesandV. anguillarum. Moreover, the optimal pH, temperature and ionic strength for rRpPLYZ activity was determined to be 5.5, 50 °C and 5 mM, respectively. These results suggested that RpPLYZ was a member of the phage-type lysozyme family and perhaps played an important role in the immune responses against bacterial invasion.