cDNA cloning and characterization of the antibacterial peptide cecropin 1 from the diamondback moth, Plutella xylostella L
cDNA cloning and characterization of the antibacterial peptide cecropin 1 from the diamondback moth, Plutella xylostella L
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小菜蛾抗菌肽天蚕素 1 的 cDNA 克隆和表征
DOI：
10.1016/j.pep.2012.08.006
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发表时间：
2012-10-01
影响因子：
1.6
通讯作者：
Ren, Shunxiang
中科院分区：
文献类型：
--
作者：
Jin, Fengliang;Sun, Qiang;Ren, Shunxiang
天蚕素是一种具有抗菌活性的线性阳离子抗菌肽。本研究利用RT-PCR技术获得了小菜蛾天蚕素1（Cecropin 1，Px-cec 1）基因的全长cDNA。北方印迹分析表明，Px-cec 1转录本主要在脂肪体、血细胞、中肠和表皮中表达，其中脂肪体中的表达水平最高。Px-cec 1 mRNA在脂肪体中的表达在微生物攻击后24 h显著增加，其中以金黄色葡萄球菌诱导的表达最高。圆二色性（CD）分析表明，重组Px-cec 1主要含有α-螺旋。抗菌实验表明，重组Px-cec 1对真菌、革兰氏阳性菌和革兰氏阴性菌具有广谱抗菌活性，但对人红细胞无溶血活性。此外，Px-cec 1还引起了S.金黄色葡萄球菌，如通过扫描电子显微镜和透射电子显微镜所示。这些结果表明Px-cec 1通过作用于细胞膜破坏细菌细胞结构来发挥其抗菌活性。(C)2012 Elsevier Inc. All rights reserved.
Cecropins are linear cationic antibacterial peptides that have potent activities against microorganisms. In the present study, a 480 bp full-length cDNA encoding diamondback moth (Plutella xylostella) cecropin 1 (designated as Px-cec1) was obtained using RT-PCR. A Northern blot analysis showed that the Px-cec1 transcript was predominantly expressed in fat bodies, hemocytes, midgut and epidermis with the highest expression level in fat bodies. The expression of Px-cec1 mRNA in fat bodies was significantly increased 24 h after microbial challenge, with the highest induced expression by Staphylococcus aureus. A circular dichroism (CD) analysis revealed that the recombinant Px-cec1 mainly contained a-helixes. Antimicrobial assays demonstrated that recombinant Px-cec1 exhibited a broad spectrum of anti-microbial properties against fungi, Gram-positive and Gram-negative bacteria, but it did not exhibit hemolytic activity against human erythrocytes. Furthermore, Px-cec1 caused significant morphological alterations of S. aureus, as shown by scanning electron microscopy and transmission electron microscopy. These results demonstrated that Px-cec1 exerts its antibacterial activity by acting on the cell membrane to disrupt bacterial cell structures. (C) 2012 Elsevier Inc. All rights reserved.