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[目的]探究家蝇抗真菌肽衍生物MAF-1C结构特点及抗白色念珠菌活性。[方法]采用氨基酸替代法设计MAF-1A衍生肽MAF-1C,生物信息学分析其理化特性,微量液体稀释法、菌落计数法检测体外抗白色念珠菌活性,扫描电镜观察对菌细胞结构的影响。[结果]MAF-1C为非跨膜阳离子线状多肽,带8个正电荷,二级结构以α螺旋为主。对白色念珠菌具有抗菌活性,MIC、MFC值分别为0.2 mg/m L和0.5 mg/m L,2×MIC浓度的MAF-1C从作用一开始就发挥抗菌作用,其作用后白色念珠菌细胞表面出现明显的凹陷、裂痕,之后细胞皱缩、裂解死亡,并且菌细胞损伤程度与肽浓度及作用时间呈正相关。[结论]MAF-1C结构参数及对白色念珠菌的抗菌活性均显著优于模板肽,对比模板肽改造后的肽阳离子电荷增加了6个,总平均疏水值(GRAVY)由-1.081升高到0.588,不稳定系数由42.27降低到5.83,MIC由0.6 mg/m L降低到0.2 mg/m L,MFC由0.7 mg/m L降低到0.5 mg/m L,其可通过破坏白色念珠菌细胞结构发挥抗菌作用。
[Objective] The research aimed to investigate the structure and anti-Candida albicans activity of MAF-1C, an antifungal peptide derivative of housefly. [Method] MAF-1A derived peptide MAF-1C was designed by amino acid substitution method. Bioinformatics analysis of its physical and chemical properties, trace liquid dilution method and colony counting method were used to test the activity against Candida albicans in vitro. The effect of scanning electron microscopy on the structure of bacterial cells . [Result] MAF-1C was a non-transmembrane cationic linear peptide with 8 positive charges, and the secondary structure was mainly α-helix. Candida albicans has antibacterial activity, MIC, MFC values were 0.2 mg / m L and 0.5 mg / m L, 2 × MIC concentration of MAF-1C from the beginning play an antimicrobial effect, the role of Candida albicans cells Surface apparent depression, cracks, then shrinkage, cell death, and bacterial cell damage and peptide concentration and duration of action was positively correlated. [Conclusion] The structure parameters of MAF-1C and the antibacterial activity against Candida albicans were significantly better than that of template peptide. The modified peptide had 6 charges increased and the total average hydrophobicity (GRAVY) increased from -1.081 to 0.588, the instability coefficient decreased from 42.27 to 5.83, the MIC decreased from 0.6 mg / m L to 0.2 mg / m L, and the MFC decreased from 0.7 mg / m L to 0.5 mg / m L, which could be caused by the destruction of C. albicans cell structure Play antibacterial effect.