High Selective Performance of Designed Antibacterial and Anticancer Peptide Amphiphiles

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• 作者：Cuixia Chen ; Yucan Chen ; Cheng Yang ; Ping Zeng ; Hai Xu ; Fang Pan ; Jian Ren Lu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：August 12, 2015
• 年：2015
• 卷：7
• 期：31
• 页码：17346-17355
• 全文大小：498K
• ISSN：1944-8252

文摘

Short designed peptide amphiphiles are attractive at killing bacteria and inhibiting cancer cell growth, and the flexibility in their structural design offers a great potential for improving their potency and biocompatibility to mammalian host cells. Amino acid sequences such as G(IIKK)_nI-NH₂ (n 鈮?3) have been shown to be membrane lytic, but terminal amino acid modifications could impose a huge influence on their performance. We report in this work how terminal amino acid modifications to G(IIKK)₃I-NH₂ influence its 伪-helical structure, membrane penetrating ability, and selective actions against different cell types. Deletion of an N-terminal Gly or a C-terminal Ile did not affect their antibacterial activity much, an observation consistent with their binding behavior to negatively charged membrane lipid monolayers. However, the cytotoxicity against mammalian cells was much worsened by the N-terminal Gly deletion, consistent with an increase in its helical content. Despite little impact on the antibacterial activity of G(IIKK)₃I-NH₂, deletion of both terminal amino acids greatly reduced its antitumor activity. Cholesterol present in tumor cell membrane-mimic was thought to constrain (IIKK)₃-NH₂ from penetrating into the cancerous membranes, evident from its lowest surface physical activity at penetrating model lipid membranes. On the other hand, its low toxicity to normal mammalian cells and high antibacterial activity in vitro and in vivo made it an attractive antibacterial agent. Thus, terminal modifications can help rebalance the different interactions involved and are highly effective at manipulating their selective membrane responses.