中文摘要：

Temporins是从蛙属中得到的一类羧基端酰胺化的疏水性抗菌肽，具有抗细菌、霉菌、酵母菌、原虫及病毒活性．为了研究牛蛙皮肤抗菌肽的多样性及其结构特点，根据GenBank数据库中蛙属抗菌肽基因信号肽序列设计简并引物，从牛蛙皮肤cDNA文库中克隆到两个新的temporins家族抗菌肽，命名为temporin—La（LLRHVVKILEKYLamide）和temporin-Lb（LFRHVVKIFEKYLamide）．合成的temporin-La和temporin-Lb肽具有很强的抗菌活性，尤其是对革兰氏阳性细菌．溶血性测定结果表明，temporin—La浓度高至250mg／L时对兔红细胞仍无溶血活性，而temporin-Lb具有较弱的溶血活性（半数致死浓度LC50≈230μmol／L）．通过透射电镜观察temporin-La和temporin—Lb处理过的金黄色葡萄球菌的细胞结构，发现它们都能直接地杀死细菌，但作用机制不一样．

英文摘要：

Temporins are a kind of small, hydrophobic and C-terminus amidated antimicrobial peptides from Rana species. They are effective against bacteria, fungi, yeast, protozoa and viruses. Two novel temporins named as temporin-La（LLRHVVKILEKYLamide） and temporin-Lb（LFRHVVKIFEKYLamide） were cloned from Lithobates catesbeianus. Synthetic peptides of temporin-La and temporin-Lb showed strong antimicrobial activities against bacteria tested, especially Gram-positive bacteria. Besides, temporin-La showed no haemolytic activity to rabbit erythrocytes at the concentration of 250 mg/L while temporin-Lb showed weak haemolytic activity（LC50 230 μmol/L）. Transmission electron microscopy showed that temporin-La and temporin-Lb induced different effects on bacterial structure of Stap hylococc us aure us.