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Methods to Inhibit Bacterial Pyomelanin Production and Determine the Corresponding Increase in Sensitivity to Oxidative Stress
Published on: August 31, 2015
Bactericidal oncocin derivatives with superior serum stabilities
Daniel Knappe1, Natalja Kabankov, Ralf Hoffmann
1Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Leipzig, Germany.
International Journal of Antimicrobial Agents
|December 28, 2010
Summary
Modified antimicrobial peptide oncocin shows increased stability and efficacy against antibiotic-resistant Gram-negative bacteria. Substituting arginine residues enhanced its half-life in serum, offering a promising new therapeutic strategy.
Area of Science:
- Biochemistry
- Microbiology
- Drug Discovery
Background:
- Antimicrobial peptides (AMPs) are crucial in combating bacterial infections.
- Increasing antibiotic resistance in Gram-negative bacteria necessitates novel therapeutic agents.
- Oncocin, a proline-rich AMP, exhibits potent in vitro activity against key pathogens.
Purpose of the Study:
- To investigate the degradation of oncocin in mouse serum.
- To enhance the stability of oncocin by modifying its arginine residues.
- To evaluate the antibacterial activity and safety of stabilized oncocin analogues.
Main Methods:
- Oncocin's arginine residues at positions 15 and 19 were substituted with various non-proteinogenic amino acids.
- The half-life of modified oncocin analogues was measured in mouse serum.
- Antibacterial activity against Gram-negative bacteria and cytotoxicity to HeLa cells and human erythrocytes were assessed.
Main Results:
- Modifications significantly increased oncocin's half-life in mouse serum, with some analogues lasting over 8 hours.
- Oncocin analogues with ornithine or D-arginine substitutions showed enhanced stability.
- The most stable analogues retained or slightly improved antibacterial activity and demonstrated low toxicity.
Conclusions:
- Stabilized oncocin analogues represent a promising strategy to overcome bacterial resistance.
- Non-proteinogenic amino acid substitutions effectively enhance AMP stability and therapeutic potential.
- Further development of these modified oncocins could lead to new treatments for challenging bacterial infections.
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