Comparative Antimicrobial Activity of Hp404 Peptide and Its Analogs against Acinetobacter baumannii
Min Ji Hong1, Min Kyung Kim1, Yoonkyung Park1,2
1Department of Biomedical Sciences, Chosun University, Gwangju 61452, Korea.
Abstract:
An amphipathic α-helical peptide, Hp1404, was isolated from the venomous gland of the scorpion Heterometrus petersii. Hp1404 exhibits antimicrobial activity against methicillin-resistant Staphylococcus aureus but is cytotoxic. In this study, we designed antimicrobial peptides by substituting amino acids at the 14 C-terminal residues of Hp1404 to reduce toxicity and improve antibacterial activity. The analog peptides, which had an amphipathic α-helical structure, were active against gram-positive and gram-negative bacteria, particularly multidrug-resistant Acinetobacter baumannii, and showed lower cytotoxicity than Hp1404. N-phenyl-1-naphthylamine uptake and DisC3-5 assays demonstrated that the peptides kill bacteria by effectively permeating the outer and cytoplasmic membranes. Additionally, the analog peptides inhibited biofilm formation largely than Hp1404 at low concentrations. These results suggest that the analog peptides of Hp1404 can be used as therapeutic agents against A. baumannii infection.
Insights
Modified scorpion peptides show potent antimicrobial activity against multidrug-resistant bacteria like Acinetobacter baumannii. These analogs exhibit reduced toxicity and effectively inhibit bacterial membranes and biofilm formation, offering therapeutic potential.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- Scorpion venom contains bioactive peptides with antimicrobial properties.
- Hp1404, an amphipathic α-helical peptide from *Heterometrus petersii* venom, displays antimicrobial activity but also significant cytotoxicity.
- There is a need for antimicrobial agents effective against multidrug-resistant bacteria, such as methicillin-resistant *Staphylococcus aureus* and *Acinetobacter baumannii*.
Purpose of the Study:
- To design and synthesize novel antimicrobial peptides based on Hp1404.
- To reduce the cytotoxicity of Hp1404 while enhancing its antibacterial efficacy.
- To evaluate the mechanism of action and antibiofilm activity of the designed analogs.
Main Methods:
- Peptide synthesis involving amino acid substitutions at the C-terminus of Hp1404.
- Antimicrobial activity assays against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains.
- Cytotoxicity assessment, membrane permeation assays (N-phenyl-1-naphthylamine uptake, DisC3-5), and antibiofilm assays.
Main Results:
- The designed analog peptides retained an amphipathic α-helical structure.
- Analogs demonstrated broad-spectrum activity against Gram-positive and Gram-negative bacteria, notably multidrug-resistant *Acinetobacter baumannii*.
- The analog peptides exhibited significantly lower cytotoxicity compared to the parent Hp1404 and effectively inhibited bacterial membrane permeation and biofilm formation.
Conclusions:
- Modified Hp1404 analogs are promising candidates for developing new antimicrobial therapies.
- These peptides effectively target bacterial membranes and inhibit biofilm formation, crucial for combating infections.
- The reduced toxicity and enhanced activity make these analogs suitable for potential therapeutic applications against resistant bacterial infections.
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