The first anionic defensin from amphibians
The first anionic defensin from amphibians
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第一个来自两栖动物的阴离子防御素
DOI：
10.1007/s00726-015-1963-8
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发表时间：
2015-07-01
期刊：
影响因子：
3.5
通讯作者：
Yang, Hailong
中科院分区：
文献类型：
--
作者：
Wei, Lin;Che, Helong;Yang, Hailong
从两栖类动物皮肤中发现了多种抗感染的抗菌肽。然而，两栖动物防御素的知识非常有限。从普氏树蛙（Polypedates puerensis）皮肤中分离纯化了一种新的阴离子防御素PopuDef，并从皮肤cDNA文库中克隆了编码PopuDef前体的cDNA。PopuDef（净电荷：-2，pI：4.75）的氨基酸序列与蝾螈防御素CFBD-1（净电荷：0，pI：6.14）的氨基酸序列同源性最高，为57%（25/44）。aerodorosaandS.金黄色葡萄球菌（MIC分别为19.41和17.25 μM），对E. coliandB.枯草杆菌（MIC分别为38.82和43.14 μM）。组织分布分析表明，PopuDef mRNA在皮肤、肠、肺和脾等免疫相关组织中有较高的表达。此外，上述不同菌株感染树蛙后，PopuDef在这些组织中的表达水平均显著上调。有趣的是，PopuDef的诱导受到E. coliorB.而对PopuDef不敏感的枯草芽孢杆菌（subtilis）对PopuDef的敏感性明显高于对P.空气动力学这些发现强调了PopuDef在抗感染的先天免疫中的关键作用。据我们所知，PopuDef是第一个从两栖动物中发现的阴离子防御素。
A variety of antimicrobial peptides against infection have been identified from the skin of amphibians. However, knowledge on amphibian defensins is very limited. A novel anionic defensin designatedPopuDef was purified from the skin of tree frogPolypedates puerensis,and the cDNA encodingPopuDef precursor was cloned from the skin cDNA library. The amino acid sequence ofPopuDef (net charge: −2, pI: 4.75) shared the highest identity of 57 % (25/44) with the salamander defensin CFBD-1 (net charge: 0, pI: 6.14) from urodela amphibians.PopuDef showed moderate antimicrobial activities againstP. aeruginosaandS. aureus(MICs are 19.41 and 17.25 μM, respectively), and relatively weak activities againstE. coliandB. subtilis(MICs are 38.82 and 43.14 μM, respectively). Tissue distribution analysis indicated that relatively high expression level ofPopuDef mRNA was observed in immune-related tissues including skin, gut, lung and spleen. Furthermore, the expression level ofPopuDef was significantly upregulated in these tissues after tree frogs were infected with different bacteria strains mentioned above. Interestingly, the induction ofPopuDef challenged withE. coliorB. subtilis,which was less sensitive toPopuDef, was much higher than that did withP. aeruginosaorS. aureus.These findings highlight the key role ofPopuDef in innate immunity against infection. To our knowledge,PopuDef is the first anionic defensin characterized from amphibians.