Ultrashort Peptide Bioconjugates Are Exclusively Antifungal Agents and Synergize with Cyclodextrin and Amphotericin B
Ultrashort Peptide Bioconjugates Are Exclusively Antifungal Agents and Synergize with Cyclodextrin and Amphotericin B
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DOI：
10.1128/aac.00468-11
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发表时间：
2012-01-01
影响因子：
4.9
通讯作者：
Shai, Yechiel
中科院分区：
文献类型：
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作者：
Arnusch, Christopher J.;Ulm, Hannah;Shai, Yechiel
许多天然广谱阳离子抗菌肽 (AMP) 具有依赖于亲脂性和电荷的一般作用模式。通过添加脂肪酸来调节 AMP 的亲脂性是增加裂解活性的有效策略，并且可以进一步拓宽 AMP 的谱。然而，缩小活性谱并专门将肽直接作用于真菌的亲脂性修饰并不常见。在这里，我们证明短肽序列可以靶向具有结构化亲脂性生物分子（例如维生素 E 和胆固醇）的真菌。该缀合物对烟曲霉、新型隐球菌和白色念珠菌具有活性，但对细菌没有活性，并且通过透射电子显微镜和膜渗透性研究观察到会引起膜扰动。然而，对于白色念珠菌，选定的化合物在不干扰细胞膜的情况下是有效的，并且与维生素 E 缀合物和两性霉素 B 具有协同作用。此外，与 β-环糊精结合，选定的化合物出现了抗菌活性。使用红细胞、巨噬细胞和小鼠的毒性测定在体外和体内测试了所选活性化合物的生物相容性。体外细胞毒性实验导致高活性抗真菌化合物的选择性毒性比（50%致死浓度/MIC）高达64，并且没有发现体内小鼠毒性。总而言之，这些结果强调了共轭亲脂结构的重要性，并表明用疏水部分（例如胆固醇和维生素 E）调节其他生物学相关的肽，可产生具有独特生物活性的化合物。
Many natural broad-spectrum cationic antimicrobial peptides (AMPs) possess a general mode of action that is dependent on lipophilicity and charge. Modulating the lipophilicity of AMPs by the addition of a fatty acid has been an effective strategy to increase the lytic activity and can further broaden the spectrum of AMPs. However, lipophilic modifications that narrow the spectrum of activity and exclusively direct peptides to fungi are less common. Here, we show that short peptide sequences can be targeted to fungi with structured lipophilic biomolecules, such as vitamin E and cholesterol. The conjugates were active against Aspergillus fumigatus, Cryptococcus neoformans, and Candida albicans but not against bacteria and were observed to cause membrane perturbation by transmission electron microscopy and in membrane permeability studies. However, for C. albicans, selected compounds were effective without the perturbation of the cell membrane, and synergism was seen with a vitamin E conjugate and amphotericin B. Moreover, in combination with beta-cyclodextrin, antibacterial activity emerged in selected compounds. Biocompatibility for selected active compounds was tested in vitro and in vivo using toxicity assays on erythrocytes, macrophages, and mice. In vitro cytotoxicity experiments led to selective toxicity ratios (50% lethal concentration/MIC) of up to 64 for highly active antifungal compounds, and no in vivo murine toxicity was seen. Taken together, these results highlight the importance of the conjugated lipophilic structure and suggest that the modulation of other biologically relevant peptides with hydrophobic moieties, such as cholesterol and vitamin E, generate compounds with unique bioactivity.