多肽dhvar4的抗细菌活性和细胞毒性研究

目的研究多肽dhvar4的抗细菌活性及其细胞毒性。方法人工合成多肽dhvar4，测定不同质量浓度dhvar4作用后的细菌生长曲线，检测dhvar4抗细菌活性；用MTT法检测不同质量浓度dhvar4对L—02、ECV-304、293和3T3细胞的细胞毒性；用溶血性实验检测不同质量浓度dhvar4对血红细胞的溶血性。结果dhvar4在4μg／ml质量浓度以上对金黄色葡萄球菌BAA42和肠球菌EF36418的生长有明显的抑制作用。在150μg／ml高质量浓度条件下，哺乳动物正常细胞存活率为68％～92％，其LD50大于150μg／ml。最大检测质量浓度(180μg／ml)下，dhvar4对血红细胞几乎没有溶血作用。结论dhvar4具有抗细菌作用，无明显细胞毒性和溶血性，具有开发成为安全高效抗细菌药物的潜在价值。

Antibacterial Activity and Cytotoxicity of Polypeptide dhvar4

OBJECTIVE: To investigate the antibacterial activity and the cytotoxicity of polypeptide dhvar4. METHODS: Solid-phase synthesized dhvar4 was manufactured by MeiLian Biotech Co. Ltd.; we evaluated its antibacterial effect, using the growth curve of bacteria after the bacteria being treated with different concentration of dhvar4. The cytotoxicity of dhvar4 on L-02, ECV-304, 293, 3T3 cells was investigated by MTT assay, and human erythrocytes were subimitted to hemolytic assay. RESULTS: dhvar4 inhibited the growth of Enterococcus faecium 36418 and Staphylococcus aureus BAA42 only at the concentration of 4 microg/ml. The viability of mammalian cells remained 68%-92% even when the concentration of dhvar4 reached 150 microg/ml. The LD50 (median lethal dose) was determined to be higher than 150 microg/ml. And very low hemolytic activity of dhvar4 was detected even at the highest protein concentration tested (180 microg/ml). CONCLUSION: dhvar4 possesses antibacterial activity and has little cytotoxicity to mammalian cells. These results suggest that dhvar4 has great potential in the development of