Biochemical property and membrane-peptide interactions of de novo antimicrobial peptides designed by helix-forming units
Biochemical property and membrane-peptide interactions of de novo antimicrobial peptides designed by helix-forming units
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螺旋形成单元从头设计的抗菌肽的生化特性和膜-肽相互作用
DOI：
10.1007/s00726-012-1334-7
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发表时间：
2012-12-01
期刊：
影响因子：
3.5
通讯作者：
Li, Zhong-Yu
中科院分区：
文献类型：
--
作者：
Ma, Qing-Quan;Dong, Na;Li, Zhong-Yu
由Phe、Ile和Arg残基组成的典型肽尚未报道，并且由三肽核心组成的螺旋形成单元（HFU）对生物活性的影响仍不清楚。在这项研究中，3-残基HFU的多聚体的设计，以研究结构与功能的关系。测定了多肽的体外生物活性。我们使用合成的脂质囊泡和完整的细菌来评估肽与细胞膜的相互作用。选择充分研究的肽蜂毒肽作为对照肽。结果表明，抗菌肽的抗菌活性和溶血活性随HFU数量的增加而增强。HFU 3具有最佳的细胞选择性，如通过治疗指数所确定的。HFU_3和HFU_4具有较强的耐盐性、耐酸碱性和耐热性。CD谱显示，在SDS或三氟乙醇（TFE）存在下，除HFU 2外的肽段均呈现富含α螺旋的二级结构。肽与两性离子磷脂（模拟哺乳动物膜）相互作用较弱，但与带负电荷的磷脂（模拟细菌膜）相互作用较强，这与生物活性的数据吻合得很好。肽的细胞选择性与其与带负电荷的磷脂的高结合亲和力之间存在相关性。细胞膜渗透性实验表明，肽靶向细胞膜，HFU 3表现出更高的内膜透性，但比蜂毒肽低的外膜透性。这些发现为利用三聚体设计具有抗菌活性的抗菌肽提供了新的思路。
Typical peptides composed of Phe, Ile, and Arg residues have not been reported, and the effect of the helix-forming unit (HFU) composed of the tripeptide core on biological activity remains unclear. In this study, multimers of the 3-residue HFU were designed to investigate the structure–function relationships. The in vitro biological activities of the peptides were determined. We used synthetic lipid vesicles and intact bacteria to assess the interactions of the peptides with cell membranes. The well-studied peptide melittin was chosen as a control peptide. The results showed that the antimicrobial and hemolytic activities of the peptides increased with the number of HFUs. HFU3 had optimal cell selectivity as determined by the therapeutic index. HFU3 and HFU4 exhibited strong resistance to salts, pH, and heat. CD spectra revealed that the peptides except HFU2 displayed α-helix-rich secondary structures in the presence of SDS or trifluoroethanol (TFE). The peptides interacted weakly with zwitterionic phospholipids (mimicking mammalian membranes) but strongly with negatively charged phospholipids (mimicking bacterial membranes), which corresponds well with the data for the biological activities. There was a correlation between the cell selectivity of the peptides and their high binding affinity with negatively charged phospholipids. Cell membrane permeability experiments suggest that the peptides targeted the cell membrane, and HFU3 showed higher permeabilization of the inner membrane but lower permeabilization of the outer membrane than melittin. These findings provide the new insights to design antimicrobial peptides with antimicrobial potency by trimers.