富含缬氨酸和赖氨酸的α-螺旋型抗菌肽的设计

Design of a amphipathic and α-helical antimicrobial peptide with Val and Lys residues

为研制新型抗菌肽,本研究采用α-螺旋轮模型设计富含缬氨酸和赖氨酸的新型抗菌肽Val_Lys(VK),并评估该新型抗菌肽的生物学活性。通过测定其圆二色谱、最小抑菌浓度(MIC)、溶血活性和细胞毒性,鉴定和评估新型抗菌肽VK的结构、生物学活性和安全性。结果表明,新型抗菌肽VK在三氟乙醇缓冲液中呈现明显的α-螺旋结构;MIC为8.0μM^16.0μM,在最大抑菌浓度256μM时仍未出现溶血活性;抗菌肽VK在64μM时,哺乳动物细胞存活率仍高达90%左右。研究结果表明该人工设计的抗菌肽具有良好抗菌生物学活性及安全性。

In this study, the new antibacterial peptide of Val_Lys （VK） was designed which was composed of Val residues in the nonpolar face and Lys residues in the polar face based on an u-helical wheel model. The circular dichrosim （CD） spectrum, minimal inhibitory concentrations （MICs）, hemolytic activity and cytotoxicity against mammalian cells were investigated to fully evaluate the biological function of the peptide. The results showed that the new peptide VK showing a significant c^-helical structure. VK had strong antimicrobial activity, and the MICs against Gram-negative and Gram-positive bacteria were 8.0-16.0 I^M. VK also showed only weak hemolysis for chicken red blood cells and cytotoxicity activity to Vero cells. Therefore, the peptide VK might be developed as a potent candidate for antimicrobial drugs.