Title:Effects of Conjugation of Ferrocene and Gallic Acid On
desCys11/Lys12/Lys13-(p-BthTX-I)2K Peptide: Structure, Permeabilization
and Antibacterial Activity
Volume: 30
Issue: 8
Author(s): Marina Rodrigues Pereira, Vanessa Rodrigues dos Santos, Warlley Campos de Oliveira, Cristiane Duque, Benise Ferreira da Silva, Norival Alves Santos-Filho, Victor Alves Carneiro, Esteban Nicolás Lorenzón and Eduardo Maffud Cilli*
Affiliation:
- Departamento de Bioquímica e Química Orgânica, Instituto de Química, Universidade Estadual Paulista (UNESP),
SP, 14800-060, São Paulo, Araraquara, Brasil
Keywords:
Antibiotics, antimicrobial peptides, bioconjugate, S. aureus, vesicle permeabilization, AMPs.
Abstract:
Background: Antimicrobial resistance is an emerging global health challenge that has
led researchers to study alternatives to conventional antibiotics. A promising alternative is antimicrobial
peptides (AMPs), produced as the first line of defense by almost all living organisms. To
improve its biological activity, the conjugation of AMPs is a promising approach.
Objective: In this study, we evaluated the N-terminal conjugation of p-Bt (a peptide derived from
Bothrops Jararacuçu`s venom) with ferrocene (Fc) and gallic acid (GA). Acetylated and linear versions
of p-Bt were also synthesized to evaluate the importance of N-terminal charge and dimeric
structure.
Methods: The compounds were obtained using solid-phase peptide synthesis. Circular dichroism,
vesicle permeabilization, antimicrobial activity, and cytotoxicity studies were conducted.
Results: No increase in antibacterial activity against Escherichia coli was observed by adding either
Fc or GA to p-Bt. However, Fc-p-Bt and GA-p-Bt exhibited improved activity against Staphylococcus
aureus. No cytotoxicity upon fibroblast was observed for GA-p-Bt. On the other hand,
conjugation with Fc increased cytotoxicity. This toxicity may be related to the membrane permeabilization
capacity of this bioconjugate, which showed the highest carboxyfluorescein leakage in vesicle
permeabilization experiments.
Conclusion: Considering these observations, our findings highlight the importance of adding bioactive
organic compounds in the N-terminal position as a tool to modulate the activity of AMPs.