鲎素抗菌肽多效协同抗菌机理的初步研究(英文)

Investigation on Multieffect and Synergistic Antibacterial Mechanism of Tachyplesin against Bacteria

为了研究鲎素的抗菌机制,采用紫外吸收法检测细菌与鲎素共同孵育前后大分子泄漏情况;采用透射电镜观察细菌和鲎素共同孵育前后细菌形态和结构的变化;采用紫外吸收法和凝胶电泳技术观察鲎素对细菌基因组DNA和质粒DNA结构的影响。结果表明,经鲎素处理的细菌,胞内生物大分子泄漏显著,细胞壁膜遭到不同程度的破坏;鲎素可与细菌基因组DNA和质粒DNA结合,高浓度鲎素可以使DNA发生断裂,进而使质粒DNA复制和转录功能受到抑制。由此可初步得出结论:鲎素抗菌肽抗菌机理是一种协同作用,包括使细菌细胞膜通透性发生变化、作用细胞质内生物功能物质、结合细胞遗传物质DNA、抑制复制转录等多效的协同的作用机制。

In order to explore antibacterial mechanism of tachyplesin, in vitro bacterial inhibition method was used to determine the feature of bacterial inhibition kinetics of tachyplesin. Ultraviolet absorption method was used to observe the leakage of large weight molecular of bacterium before and after being incubated with tachyplesin. Transmission electron microscopy （TEM） was adopted to investigate the morphologic and structural changes of bacterium before and after being incubated with tachyplesin. Ultroviolet absorption method and electrophoretic mobility shift assay （EMSA） were used to investigate the effect of tachyplesin on structure of genomic DNA and plasmid DNA of bacterium. The results showed that bacterium lost large weight molecular and cell wall, cell membrane and whole cell were damaged to some extent after treated by tachyplesin. Tachyplesin could combine with genomic DNA and plasmid DNA of bacterium,high concentration of tachyplesin could break DNA, hence inhibit copy and transcription of plasmid DNA. It was suggested that the antibacterial targets include at least cell wall and cell membrane and DNA of bacterium.