High Specific Selectivity and Membrane-Active Mechanism of Synthetic Cationic Hybrid Antimicrobial Peptides Based on the Peptide FV7.

Tingting Tan,Di Wu,Weizhong Li,Anshan Shan,Weifen Li,Xin Zheng

doi:10.3390/ijms18020339

Abstract

Hybrid peptides integrating different functional domains of peptides have many advantages, such as remarkable antimicrobial activity, lower hemolysis and ideal cell selectivity, compared with natural antimicrobial peptides. FV7 (FRIRVRV-NH2), a consensus amphiphilic sequence was identified as being analogous to host defense peptides. In this study, we designed a series of hybrid peptides FV7-LL-37 (17–29) (FV-LL), FV7-magainin 2 (9–21) (FV-MA) and FV7-cecropin A (1–8) (FV-CE) by combining the FV7 sequence with the small functional sequences LL-37 (17–29) (LL), magainin 2 (9–21) (MA) and cecropin A (1–8) (CE) which all come from well-described natural peptides. The results demonstrated that the synthetic hybrid peptides, in particular FV-LL, had potent antibacterial activities over a wide range of Gram-negative and Gram-positive bacteria with lower hemolytic activity than other peptides. Furthermore, fluorescent spectroscopy indicated that the hybrid peptide FV-LL exhibited marked membrane destruction by inducing outer and inner bacterial membrane permeabilization, while scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that FV-LL damaged membrane integrity by disrupting the bacterial membrane. Inhibiting biofilm formation assays also showed that FV-LL had similar anti-biofilm activity compared with the functional peptide sequence FV7. Synthetic cationic hybrid peptides based on FV7 could provide new models for combining different functional domains and demonstrate effective avenues to screen for novel antimicrobial agents.

Highlights

Occurring antimicrobial peptides (AMPs) are considered potential anti-infective agents primarily due to their antimicrobial or immunomodulatory properties [1,2,3,4,5,6,7,8,9]
These hybrid peptides were termed as FV-LL (FV7 followed by residues 17–29 of LL-37), FV-MA (FV7 followed by residues 9–21 of magainin 2) and FV-CE (FV7 followed by residues 1–8 of cecropin A) respectively (Table 1)
We designed a series of synthetic cationic hybrid antimicrobial peptides based on the peptide FV7 combined with fragments of the different natural peptides LL-37, magainin 2 and cecropin A, which have previously been determined to be optimal for antibacterial activity and cell selectivity

Summary

Introduction

Occurring antimicrobial peptides (AMPs) are considered potential anti-infective agents primarily due to their antimicrobial or immunomodulatory properties [1,2,3,4,5,6,7,8,9]. Several concerns may weaken their development as antimicrobial agents which include their potential cytotoxicity, poor antimicrobial activity based on peptide concentration and weak physiological stability [13] Various modifications such as substitutions of specific amino acids [14] and truncation of parental peptides [15] have been employed to improve antimicrobial activity and physiological stability and reduce cytotoxic effects simultaneously. These changes were short of the systematic scientific rationale which aimed to improve AMP design principles. There is a strong focus on developing novel hybrid peptides of therapeutic value based on the peptide FV7

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Conclusion