Peptoid-Substituted Hybrid Antimicrobial Peptide Derived from Papiliocin and Magainin 2 with Enhanced Bacterial Selectivity and Anti-inflammatory Activity

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• 作者：Areum Shin ; Eunjung Lee ; Dasom Jeon ; Young-Guen Park ; Jeong Kyu Bang ; Yong-Sun Park ; Song Yub Shin ; Yangmee Kim
• 刊名：Biochemistry
• 出版年：2015
• 出版时间：June 30, 2015
• 年：2015
• 卷：54
• 期：25
• 页码：3921-3931
• 全文大小：450K
• ISSN：1520-4995

文摘

Antimicrobial peptides (AMPs) are important components of the host innate immune system. Papiliocin is a 37-residue AMP purified from larvae of the swallowtail butterfly Papilio xuthus. Magainin 2 is a 23-residue AMP purified from the skin of the African clawed frog Xenopus laevis. We designed an 18-residue hybrid peptide (PapMA) incorporating N-terminal residues 1鈥? of papiliocin and N-terminal residues 4鈥?2 of magainin 2, joined by a proline (Pro) hinge. PapMA showed high antimicrobial activity but was cytotoxic to mammalian cells. To decrease PapMA cytotoxicity, we designed a lysine (Lys) peptoid analogue, PapMA-k, which retained high antimicrobial activity but displayed cytotoxicity lower than that of PapMA. Fluorescent dye leakage experiments and confocal microscopy showed that PapMA targeted bacterial cell membranes whereas PapMA-k penetrated bacterial cell membranes. Nuclear magnetic resonance experiments revealed that PapMA contained an N-terminal 伪-helix from Lys³ to Lys⁷ and a C-terminal 伪-helix from Lys¹⁰ to Lys¹⁷, with a Pro⁹ hinge between them. PapMA-k also had two 伪-helical structures in the same region connected with a flexible hinge residue at Nlys⁹, which existed in a dynamic equilibrium of cis and trans conformers. Using lipopolysaccharide-stimulated RAW264.7 macrophages, the anti-inflammatory activity of PapMA and PapMA-k was confirmed by inhibition of nitric oxide and inflammatory cytokine production. In addition, treatment with PapMA and PapMA-k decreased the level of ultraviolet irradiation-induced expression of genes encoding matrix metalloproteinase-1 (MMP-1), interleukin-6 (IL-6), and tumor necrosis factor-伪 (TNF-伪) in human keratinocyte HaCaT cells. Thus, PapMA and PapMA-k are potent peptide antibiotics with antimicrobial and anti-inflammatory activity, with PapMA-k displaying enhanced bacterial selectivity.