Thaulin-1: The first antimicrobial peptide isolated from the skin of a Patagonian frog Pleurodema thaul (Anura: Leptodactylidae: Leiuperinae) with activity against Escherichia coli

• Published in: Gene 2017-03, Vol.605, p.70-80
• Main Authors: Marani, Mariela M., Perez, Luis O., de Araujo, Alyne Rodrigues, Plácido, Alexandra, Sousa, Carla F., Quelemes, Patrick Veras, Oliveira, Mayara, Gomes-Alves, Ana G., Pueta, Mariana, Gameiro, Paula, Tomás, Ana M., Delerue-Matos, Cristina, Eaton, Peter, Camperi, Silvia A., Basso, Néstor G., de Souza de Almeida Leite, Jose Roberto
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amphibian Proteins - biosynthesis; Amphibian Proteins - chemical synthesis; Amphibian Proteins - isolation & purification; Amphibian Proteins - pharmacology; Animals; Antimicrobial Cationic Peptides - biosynthesis; Antimicrobial Cationic Peptides - chemical synthesis; Antimicrobial Cationic Peptides - isolation & purification; Antimicrobial Cationic Peptides - pharmacology; Anura; Anura - genetics; Anura - metabolism; Atomic force microscopy; Base Sequence; cDNA; Cell Survival - drug effects; Circular dichroism; DNA, Complementary - genetics; DNA, Complementary - metabolism; Erythrocytes - drug effects; Escherichia coli - chemistry; Escherichia coli - drug effects; Escherichia coli - growth & development; Gene Expression; Klebsiella pneumoniae - drug effects; Klebsiella pneumoniae - growth & development; Macrophages - drug effects; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests; Models, Molecular; Protein Structure, Secondary; Sequence Alignment; Skin - chemistry; Skin - metabolism; Solid-Phase Synthesis Techniques; Staphylococcus aureus - drug effects; Staphylococcus aureus - growth & development; Surface Plasmon Resonance
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/j.gene.2016.12.020

Patagonia's biodiversity has been explored from many points of view, however, skin secretions of native amphibians have not been evaluated for antimicrobial peptide research until now. In this sense, Pleurodema thaul is the first amphibian specie to be studied from this large region of South America. Analysis of cDNA-encoding peptide in skin samples allowed identification of four new antimicrobial peptides. The predicted mature peptides were synthesized and all of them showed weak or null antimicrobial activity against Klebsiella pneumoniae, Staphylococcus aureus and Escherichia coli with the exception of thaulin-1, a cationic 26-residue linear, amphipathic, Gly- and Leu-rich peptide with moderate antimicrobial activity against E. coli (MIC of 24.7μM). AFM and SPR studies suggested a preferential interaction between these peptides and bacterial membranes. Cytotoxicity assays showed that thaulin peptides had minimal effects at MIC concentrations towards human and animal cells. These are the first peptides described for amphibians of the Pleurodema genus. These findings highlight the potential of the Patagonian region's unexplored biodiversity as a source for new molecule discovery. [Display omitted] •Thaulin-1 is the first antimicrobial peptide isolated from the skin of P. thaul.•Thaulin-1 is a Gly/Leu-rich peptide with similarities to bombinin peptide family.•In organic media, thaulin-1 showed characteristic CD spectra of α–helix structures.•Thaulin-1 presents activity against E. coli, K. pneumoniae and S. aureus strains.•Thaulin-1 showed low cytotoxicity to mammalian cells.