抗菌肽TachyplesinⅠ的分子设计、结构与活性分析  

Molecular Design,Structure and Activity Analysis of Antimicrobial Peptide Tachyplesin I

作　　者：孙栋 蔡寅川 蒋思雨 李璇 郝刚[1] SUN Dong;CAI Yinchuan;JIANG Siyu;LI Xuan;HAO Gang(College of Food Science and Technology, Southwest Minzu University, Chengdu 610041, China;The Research Institute of Industrial Economy of Aba, Wenchuan 623000, China;Chongqing Academy of Metrology and Quality Inspection, Chongqing 401120, China)

机构地区：[1]西南民族大学食品科学与技术学院,成都610041 [2]四川阿坝州工业经济研究所,汶川623000 [3]重庆市计量质量检测研究院,重庆401120

出　　处：《畜牧兽医学报》2022年第6期1905-1913,共9页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家重点研发计划(2018YFD0400101);西南民族大学研究生创新型科研项目(CX2021SZ75)。

摘　　要：本研究旨在抗菌肽TachyplesinⅠ(TPⅠ)的结构活性基础上,重新设计一种全新的抗菌肽TPⅠ-Y4。保持母肽链长与电荷数不变,将序列中形成TPⅠ两个二硫键的4个半胱氨酸用酪氨酸进行替换后得到TPⅠ-Y4。经生物信息学软件分析,与TPⅠ相比,TPⅠ-Y4的热稳定性更好,亲水性更强,同时具有与母肽相似的结构与抗菌活性。化学合成后经圆二色谱检测发现,TPⅠ-Y4在水相及在模拟细胞膜疏水环境的50%三氟乙醇中都表现出β-折叠结构,疏水环境中TPⅠ-Y4的β-折叠含量高于水相,也高于不同环境中的TPⅠ。抑菌试验表明,TPⅠ-Y4对细菌和真菌都有较强抑菌活性,且对细菌的抑菌活性强于TPⅠ。TPⅠ-Y4对小鼠红细胞溶血性降低,并保留了很强的内毒素中和能力,浓度为40μg·mL^(-1)时中和率可达50%以上。TPⅠ-Y4抗菌活性的提高以及溶血活性的降低,可能与β-折叠强形成者酪氨酸的替代有关,进而导致抗菌肽分子中β-折叠结构增强。Based on the structure-activity relationship of the antimicrobial peptide tachyplesinⅠ(TPⅠ),a novel antimicrobial peptide TPⅠ-Y4 was designed out.TPⅠ-Y4 was obtained by replacing four cysteines with tyrosines to delete two disulfide bonds of TPⅠ,keeping the chain length and charge number of the parent peptide.The results of bioinformatics software analysis had discovered that compared with TPⅠ,TPⅠ-Y4 had better thermal stability,stronger hydrophilicity,and similar structure and antibacterial activity to propeptide.After chemical synthesis,the results of circular dichroism spectroscopy had showed that TPⅠ-Y4 also adoptedβ-sheet structure in aqueous phase and 50%trifluoroethanol solution which simulated the hydrophobic environment of cell membrane.Theβ-sheet contents of TPⅠ-Y4 in hydrophobic environment were higher than that in aqueous phase.TPⅠ-Y4 exhibited higherβ-sheet contents than TPⅠin different environments.TPⅠ-Y4 owned potent antimicrobial activities against bacteria and fungi,and TPⅠ-Y4 displayed stronger antimicrobial activities against bacteria tested than TPⅠ.TPⅠ-Y4 reduced the hemolysis of mouse red blood cells and retained a strong endotoxin neutralization ability,the neutralization rate reached more than 50%when the concentration was 40μg·mL^(-1).The results suggest that the increase of TP I-Y4 antibacterial activity and the decrease of hemolytic activity may be related to the substitution of tyrosine,asβ-sheet strong-former which further leads to the enhancement ofβ-sheet structure in antimicrobial peptide.

关 键 词：抗菌肽 TachyplesinⅠ 分子设计 圆二色谱 抑菌活性 

分 类 号：S816[农业科学—饲料科学]