人源性多肽pCM-19抗菌机制的初步研究

目的：初步分析人源性多肽pCM-19的抗菌作用机制。方法：利用荧光素掺入破损细胞膜的原理，采用流式荧光激活细胞分析（FACScan）和扫描电子显微镜分析pCM-19对靶菌膜的作用机制。结果：FACS分析法结果显示pCM-19处理后的大肠杆菌PI着染细菌比例明显高于未处理组，并且随作用时间的延长，PI着染BL-21菌比例增大，20min时达最高水平，20min以后反而降低；扫描电子显微镜观察到pCM-19处理后的大肠杆菌有明显的表面形态学的改变，如细菌体积缩小、细菌表面出现皱缩、凹陷似有孔洞形成。结论：人源性多肽pCM-19可能作用于细菌细胞壁和（或）细胞膜，通过改变其通透性而发挥杀菌作用。

Preliminary studies of antibacterial mechanism of human-derived peptide pCM-19

Objective: To explore the antibacterial mechanism of synthetic peptide pCM-19 designed according to a human-derived novel hGlyrichin gene.Methods: The fluorescence activated flow cytometry(FACScan)analysis was performed using the principle of incorporation propidium iodide(PI) into the cells with membrane disturbance or dead cells and scanning electron microscopy to examine the morphologic changes in target bacterium after treatment with pCM-19 or notreatment.Results: FACScan analysis showed that the percentage of PI positive cells in pCM-19 treated sample was much higher than that in untreated one.Moreover,the percentage of positive cells gradually increased with increasing incubation time up to 20 min,implying that the target cell membrane was disrupted gradually when interacted with pCM-19 and at the same time PI was incorporated into the cells with membrane disrupted.To find more evidence of morphologic changes,the target bacterium was examined using scanning electron microscopy,and it showed that pCM-19 caused significant morphological alterations in the cell size and membrane of the target bacteria comparing with the control bacteria.Conclusion: pCM-19 probably affects the cell wall and(or) membrane of the target bacteria,killing them by changing the permeability of membrane.