【摘要】 目的合成抗菌肽Cn-AMP2并用光谱学方法研究其抗革兰阴性菌和革兰阳性菌的作用机制。方法通过Fmoc固相合成的方式制备抗菌肽Cn-AMP2并测定抗菌肽Cn-AMP2对不同菌株的最低抑菌浓度。使用圆二色光谱法测定抗菌肽Cn-AMP2在不同缓冲溶液体系中的二级结构;以N-苯基-1-萘胺为探针进行细胞外膜渗透性实验。以溴化乙锭为荧光探针,通过肽与DNA竞争结合荧光光谱研究抗菌肽Cn-AMP2对细菌基因组DNA作用。结果通过Fmoc固相合成制备的抗菌肽Cn-AMP2经高效液相色谱纯化后,质谱测定分子量为1 266.40Da,表明合成无误。对革兰阴性菌和革兰阳性菌均具有较强的杀伤作用。针对不同菌株,最低抑菌浓度MIC为50.0~100.0μg/mL。在圆二色光谱测定结果表明抗菌肽Cn-AMP2为螺旋结构多肽。在模拟的疏水环境下,其摩尔椭圆率为-2 548 degree·cm~2·dmo~l(-1)。在细菌外膜渗透性实验表明细胞膜是抗菌肽的作用靶点。抗菌肽Cn-AMP2与基因组DNA具有结合能力,表明基因组DNA也是作用靶点。结论抗菌肽Cn-AMP2通过作用于细胞膜和基因组DNA产生抗菌作用。更多还原

【Abstract】 Objective To research the effect mechanism of anti-gram-negative bacteria and gram-positive bacteria by the spectroscopy of antimicrobial mechanism of antibacterial pep tide Cn-AMP2 double target. Methods The antibacterial pep tide Cn-AMP2 was prepared by the Fmoc solid phase synthesis way and the minimum inhibitory concentration of antibacterial pep tide Cn-AMP2 to different strains was measured, and the second-level structure of antibacterial pep tide Cn-AMP2 in different buffer solution system was measured by the circular dichroism spectrum, and the Nphenyl-1-naphthylamine was used as the probe for epicardial permeability test, and the homidium bromide was used as the fluorescent probe, and the effect of antibacterial pep tide Cn-AMP2 on the bacterial gene group DNA was studied by the pep tide, DNA and fluorescence spectrum. Results After the antibacterial pep tide Cn-AMP2 prepared by the Fmoc solid phase synthesis was for high performance liquid chromatography purification, the molecular weight measured by the mass spectrum was 1 266.40 Da, showing unmistakable synthesis, and having the strong lethal effect on the gram-negative bacteria and gram-positive bacteria.For different strains, the minimum inhibitory concentration MIC was 50.0 to 100 μg/mL, and the measurement results of circular dichroism showed that the antibacterial pep tide Cn-AMP2 was spiral structural polypeptide. In a simulated hydrophobic environment,the molar ellipticity was-2 548 degree·cm²·dmol^-1. The epicardial permeability test proved that the cell membrane was the function target point of antibiotic peptide. The antibacterial pep tide Cn-AMP2 had the combination ability with the DNA in the gene group, showing the DNA in the gene group was also the function target. Conclusion The antibacterial pep tide Cn-AMP2 produces the antibacterial action by acting on the cell membrane and genomic DNA.更多还原