Amphiphilic alpha‐helices are common motifs used in numerous biological systems including membrane channels/pores and antimicrobial peptides (AMPs), and binding proteins, and a variety of synthetic biomaterials. Previously, an amphiphilic peptide with lysine‐containing motifs was shown to reversibly bind the anionic porphyrin meso‐Tetra(4‐sulfonatophenyl)porphyrin () and promote the formation of excitonically coupled conductive J‐aggregates. The work presented here focuses on the use of this amphiphilic peptide and derivatives as a potential antimicrobial agent. AMPs are naturally occurring components of the innate immune system, which selectively target and kill bacteria. Sequence derivatives were synthesized in which the position of the Trp, used as a fluorescence reporter, was changed. Additional variants were synthesized where the hydrophobic amino acids were replaced with Ala to reduce net hydrophobicity or where the cationic Lys residues were replaced with diaminopropionic acid (Dap). All peptide sequences retained the ability to bind and promote the formation of J‐aggregates. The peptides all exhibited a preference for binding anionic lipid vesicles compared to zwitterionic bilayers. The Trp position did not impact antimicrobial activity, but the substituted peptides exhibited markedly lower efficacy. The Dap‐containing peptide was only active against E. coli and P. aeruginosa, while the Ala‐substituted peptide was inactive at the concentrations tested. This trend was also evident in bacterial membrane permeabilization. The results indicate that the amphiphilic porphyrin binding peptides can also be used as antimicrobial peptides. The cationic nature is a driver in binding to lipid bilayers, but the overall hydrophobicity is important for antimicrobial activity and membrane disruption.

中文翻译：

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卟啉结合肽的抗菌活性。

两亲性α-螺旋是许多生物系统中常用的基序，包括膜通道/孔和抗菌肽（AMP），结合蛋白以及多种合成生物材料。以前，显示具有赖氨酸基序的两亲性肽可逆地结合阴离子卟啉内消旋四（4-磺酰基苯基）卟啉（）并促进激子耦合导电J聚集体的形成。本文介绍的工作重点在于使用这种两亲性肽及其衍生物作为潜在的抗菌剂。AMP是先天免疫系统的天然成分，可选择性地靶向并杀死细菌。合成了序列衍生物，其中改变了用作荧光报告基因的Trp的位置。合成了其他变体，其中疏水氨基酸被Ala取代以降低净疏水性，或者阳离子Lys残基被二氨基丙酸（Dap）取代。所有肽序列都保留了结合能力并促进J骨料的形成。与两性离子双层相比，所有肽均表现出对结合阴离子脂质囊泡的偏好。Trp位置不影响抗菌活性，但取代的肽显示出明显较低的功效。含有Dap的肽仅对大肠杆菌和铜绿假单胞菌具有活性，而经Ala取代的肽在测试浓度下无活性。这种趋势在细菌膜通透性中也很明显。结果表明，两亲性卟啉结合肽也可以用作抗微生物肽。阳离子性质是与脂质双层结合的驱动力，但总体疏水性对于抗菌活性和膜破坏很重要。