摘要
To develop novel antimicrobial peptides (AMPs) with improved cell selectivity and potent LPS-neutralizing activity, we synthesized an 18 N-terminal residues peptide (BAMP-18) of bovine myeloid antimicrobial peptide-27 (BMAP-27) and its analogs (BMAP-18-W, BMAP-18-L, BMAP-18-I and BMAP-18-f). BMAP-18 and its analogs displayed much higher cell selectivity (about 4–97-fold increased) as compared to parental BMAP-27 because of their decreased hemolytic activity and retained antimicrobial activity. BMAP-27 caused near-complete dye leakage from bacterial-membrane-mimicking vesicles even at very low concentration of 0.5 μM, whereas BMAP-18 and its analogs induced very little dye leakage (less than 40%) even at 16 μM. These peptides induced near-complete membrane depolarization of Staphylococcus aureus cells under their MIC (4 μM). These results suggests that BMAP-18 and its analogs exhibit lethality toward microbes due to their ability to form small channels that permit the transit of ions or protons, but not molecules as large as calcein, and not by the membrane-disruption/perturbation mode. BMAP-18 and its analogs significantly inhibited nitric oxide (NO) production or tumor necrosis factor-α (TNF-α) release in LPS-stimulated mouse macrophage RAW264.7 cells at 10 μM. In particular, BMAP-18-W showed LPS-neutralizing activity comparable to that of BMAP-27. There was a significant linear correlation between the increase in the hydrophobicity of peptides and LPS-neutralizing activity. Although BMAP-18-W has lower hydrophobicity than BMAP-18-L, it showed higher LPS-neutralizing activity as compared to BMAP-18-L. This result suggests other important parameters of AMPs may be involved in their LPS-neutralizing activity, as well as positive charge and hydrophobicity.
摘要译文
为了开发新型抗菌肽（AMPS）与改善细胞的选择性和强效毒素中和活性，我们合成了18个N端残基肽（BAMP-18）牛骨髓抗菌肽-27（BMAP-27）及其类似物（BMAP的-18-W，BMAP-18-L，BMAP-18-I和BMAP-18-f）的。BMAP-18和它的类似物显示高得多的细胞选择性（约4-97倍增加）相比，因为它们降低溶血活性育儿BMAP-27并保持抗微生物活性。BMAP-27，即使在0.5μM浓度非常低而引起从细菌 - 膜 - 模仿囊泡近乎完全染料渗漏，而BMAP-18和它的类似物诱导很少的染料泄漏（小于40％25），即使在16微米。这些肽诱导几乎完全隔膜的金黄色葡萄球菌细胞的去极化下的MIC（4μM）。这些结果表明BMAP-18和它的类似物显示出，由于其形成的小通道，其允许离子或质子的中转，但不是分子一样大钙黄绿素，而不是由膜破坏/扰动模式能力杀伤力朝向微生物。BMAP-18和它的类似物显著抑制一氧化氮（NO）的生产或肿瘤坏死因子α（TNF-α）释放的LPS刺激的小鼠巨噬细胞的RAW264.7细胞以10μM。特别是，BMAP-18-W表明LPS中和活性比得上BMAP-27的。有增加的肽和LPS中和活性的疏水性之间的显著线性相关。虽然BMAP-18-W具有疏水性比BMAP-18-L时，它表现出较高的LPS中和活性相比，BMAP-18-L。这一结果表明抗菌肽可能参与在其内毒素中和活性的其它重要参数，以及正电荷和疏水性。
Eun Kyu Lee[a][1]; Yoon-Chang Kim[b][1]; Yong Hai Nan[a]; Song Yub Shin[a][c]. Cell selectivity, mechanism of action and LPS-neutralizing activity of bovine myeloid antimicrobial peptide-18 (BMAP-18) and its analogs[J]. Peptides, 2011,32(6): 1123–1130