Antibacterial activity of new Aurein analogs containing lysine and fluorinated phenylalanine

Author : Veronica Nemska, Nora Angelova, Tsvetelina Foteva, Nelly Georgieva, Dancho Danalev, Emilia Naydenova

Abstract :Aurein 1.2 (GLFDIIKKIAESF-NH2) is a short-chain, multifunctional antimicrobial peptide, primarily isolated from the Australian bell frog Litoria aurea. However, the absence of strong activity failed to provide it with a competitive advantage for further use as a therapeutic agent. This necessitates a modification of the design of the peptide structure to improve its action and efficiency. The purpose of the present study was to investigate the antimicrobial activity of Aurein 1.2 analogs, substituted with Lys residue in position 4 and 4-fluorophenylalanine residue in positions 3 and 13 solely and in combination, against Escherichia coli NBIMCC 8785 and Bacillus subtilis NBIMCC 3562. The analogs were obtained via solid-phase peptide synthesis. Their antibacterial activity was assessed by measuring the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against both strains. The MIC was determined using the broth microdilution method, while the MBC was assessed through the plate count method. The modifications significantly increased the antibacterial effect of Aurein 1.2, with stronger action observed against B. subtilis NBIMCC 3562. Among the analogs tested, the most potent activity against both strains is observed with the analog, containing Lys residue in position 4 and 4-fluorophenylalanine residue in position 13.

Keywords :This study is funded by the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, project № BG-RRP-2.004.0002, “BiOrgaMCT”

Conference Name :International Conference on Environment, Biotechnology and Bioengineering Applications (ICEBBA-25)

Conference Place Zurich, Switzerland

Conference Date 17th Jul 2025