Author(s):
Plácido, Alexandra ; Amaral, Constança do Pais do ; Teixeira, Cátia ; Nogueira, Ariane ; Brango-Vanegas, José ; Barbosa, Eder Alves ; Moreira, Daniel C. ; Silva-Carvalho, Amanda É. ; Silva, Maria da Gloria da ; Dias, Jhones do Nascimento ; Albuquerque, Patrícia ; Saldanha-Araújo, Felipe ; Lima, Filipe C. D. A. ; Batagin-Neto, Augusto ; Kuckelhaus, Selma ; Bessa, Lucinda J. ; Freitas, Jaime ; Brand, Guilherme Dotto ; Santos, Nuno C. ; Relvas, João B. ; Gomes, Paula ; Leite, José Roberto S. A. ; Eaton, Peter
Date: 2022
Persistent ID: http://hdl.handle.net/10400.26/59927
Origin: Egas Moniz - Cooperativa de Ensino Superior, CRL
Subject(s): Amphibia; antioxidant; bioactive peptide; neuroprotection; Pelophylax perezi; tryptophyllin
Description
Tryptophyllins constitute a heterogeneous group of peptides that are one of the first classes of peptides identified from amphibian’s skin secretions. Here, we report the structural characterization and antioxidant properties of a novel tryptophyllin-like peptide, named PpT-2, isolated from the Iberian green frog Pelophylax perezi. The skin secretion of P. perezi was obtained by electrical stimulation and fractionated using RP-HPLC. De novo peptide sequencing was conducted using MALDI MS/MS. The primary structure of PpT-2 (FPWLLS-NH2) was confirmed by Edman degradation and subsequently investigated using in silico tools. PpT-2 shared physicochemical properties with other well-known antioxidants. To test PpT-2 for antioxidant activity in vitro, the peptide was synthesized by solid phase and assessed in the chemical-based ABTS and DPPH scavenging assays. Then, a flow cytometry experiment was conducted to assess PpT-2 antioxidant activity in oxidatively challenged murine microglial cells. As predicted by the in silico analyses, PpT-2 scavenged free radicals in vitro and suppressed the generation of reactive species in PMA-stimulated BV-2 microglia cells. We further explored possible bioactivities of PpT-2 against prostate cancer cells and bacteria, against which the peptide exerted a moderate antiproliferative effect and negligible antimicrobial activity. The biocompatibility of PpT-2 was evaluated in cytotoxicity assays and in vivo toxicity with Galleria mellonella. No toxicity was detected in cells treated with up to 512 µg/ml and in G. mellonella treated with up to 40 mg/kg PpT-2. This novel peptide, PpT-2, stands as a promising peptide with potential therapeutic and biotechnological applications, mainly for the treatment/prevention of neurodegenerative disorders.
