Identification of antimicrobial peptides from teleosts and anurans in expressed sequence tag databases using conserved signal sequences
Identification of antimicrobial peptides from teleosts and anurans in expressed sequence tag databases using conserved signal sequences
复制标题
DOI：
10.1111/j.1742-4658.2011.08463.x
复制
发表时间：
2012-03
期刊：
影响因子：
--
通讯作者：
Valentina Tessera;F. Guida;D. Juretic;A. Tossi
中科院分区：
文献类型：
--
作者：
Valentina Tessera;F. Guida;D. Juretic;A. Tossi
多药耐药问题要求有效和准确地鉴定新型抗菌药物。大多数生物产生的内源性抗菌肽是这类分子的有希望的来源。我们利用硬骨鱼和无尾鱼抗菌肽中信号序列的高度保守性来搜索cDNA（表达序列标签）数据库以寻找可能的候选者。然后根据理化性质（两性螺旋结构、阳离子性）分析受试者序列是否存在潜在的抗菌肽，并使用D - descriptor模型预测治疗指数（最低抑制浓度与50%溶血浓度之间的关系）。这一分析还建议突变来探索初级结构在决定效力和选择性中的作用。化学合成了选定的序列，并对其抗菌活性进行了验证。特别是，一个短的（21‐残基）序列，可能来源于棘鱼，显示出强大的活性，并且可以通过组合三个定向突变来调整作用谱和/或选择性。对细菌和宿主细胞的膜渗透研究表明，作用方式主要是膜溶解。该方法为更有效地搜索庞大且不断增长的新型抗菌肽表达序列标签数据库提供了可能，这些数据库可能丰富，并有效地识别其中最有希望的候选物。
The problem of multidrug resistance requires the efficient and accurate identification of new classes of antimicrobial agents. Endogenous antimicrobial peptides produced by most organisms are a promising source of such molecules. We have exploited the high conservation of signal sequences in teleost and anuran antimicrobial peptides to search cDNA (expressed sequence tag) databases for likely candidates. Subject sequences were then analysed for the presence of potential antimicrobial peptides based on physicochemical properties (amphipathic helical structure, cationicity) and use of the D‐descriptor model to predict the therapeutic index (relation between the minimum inhibitory concentration and the concentration giving 50% haemolysis). This analysis also suggested mutations to probe the role of the primary structure in determining potency and selectivity. Selected sequences were chemically synthesized and the antimicrobial activity of the peptides was confirmed. In particular, a short (21‐residue) sequence, likely of sticklefish origin, showed potent activity and it was possible to tune the spectrum of action and/or selectivity by combining three directed mutations. Membrane permeabilization studies on both bacterial and host cells indicate that the mode of action was prevalently membranolytic. This method opens up the possibility for more effective searching of the vast and continuously growing expressed sequence tag databases for novel antimicrobial peptides, which are likely abundant, and the efficient identification of the most promising candidates among them.