Interaction of synthetic antimicrobial peptides of the Hylin a1 family with models of eukaryotic structures: Zwitterionic membranes and DNA

Autor(es)

Vignoli Muniz, Gabriel S. ^[1] ; De la Torre, I, Lilia ; Duarte, Evandro L. ^[1] ; Lorenzon, Esteban N. ^[2] ; Cilli, Eduardo M. ^[3] ; Balan, Andrea ^[4] ; Teresa Lamy, M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis, Sao Paulo, SP - Brazil

^[2] Univ Fed Jatai, Unidade Academ Especial Ciencias Saude, Jatai, Go - Brazil

^[3] Univ Estadual Paulista, Inst Quim, Araraquara, SP - Brazil

^[4] De la Torre, Lilia, I, Univ Sao Paulo, Inst Ciencias Biomed, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BIOCHEMISTRY AND BIOPHYSICS REPORTS; v. 24, DEC 2020.
• Citações Web of Science: 1

Resumo

Antimicrobial peptides (AMPs) have been appointed as a possible alternative to traditional antibiotics in face of pathogens increasing resistance to conventional drugs. Hylin a1 (IFGAILPLALGALKNLIK), an AMP extracted from the skin secretion of a South American frog, Hypsiboas albopunctatus, was found to show a strong cytotoxicity against bacteria and fungus, but also a considerable hemolytic action. Considering the toxicity of the peptide in eukaryotic cells, this work focuses on investigating the effects of the interaction of the Hylin a1 analogues W(6)Hya1, D(0)W(6)Hya1 and K(0)W(6)Hya1 with models of eukaryotic structures, namely zwitterionic liposomes of dipalmitoyl phosphatidylcholine (DPPC) and calf-thymus DNA (CT DNA). Through intrinsic Trp fluorescence we determined that the peptide affinity for fluid DPPC bilayers follows the decreasing order: D(0)W(6)Hya1 (+2) > W(6)Hya1 (+3) >> K(0)W(6)Hya1 (+4). Fluorescence data also indicate that the Trp residue in the more positively charged peptide, K(0)W(6)Hya1, is less deep in the bilayer than the residue in the other two peptides. This finding is supported by differential scanning calorimetry (DSC) data, which shows that both D(0)W(6)Hya1 and W(6)Hya1 disturb DPPC gel-fluid transition slightly more effectively than K(0)W(6)Hya1. DPPC DSC profiles are homogeneously disturbed by the three peptides, probably related to peptide-membrane diffusion. Surprisingly, the peptide that displays the lowest affinity for PC membranes and is located at the more superficial position in the bilayer, K(0)W(6)Hya1, is the most efficient in causing formation of pores on the membrane, as attested by carboxyfluorescein leakage assays. The three peptides were found to interact with CT DNA, with a deep penetration of the Trp residue into hydrophobic pockets of the double helix, as indicated by the significant blue shift on the Trp fluorescence, and the displacement of DNA-bound ethidium bromide by the peptides. The experiments of DNA electrophoresis confirm that Hylin peptides bind DNA in a concentration-dependent manner, inducing complete DNA retardation at the relative AMP/plasmid DNA weight ratio of similar to 17. These findings could help to better understand the AMPs toxic effects on eukaryotic cells, thus contributing to the design of healthier therapeutic agents. (AU)

• Processo FAPESP: 18/20162-9 - Investigando a Patogênese e a Resistência à Drogas em Microrganismos - Caracterização e Controle de Transportadores ABC
• Beneficiário: Andrea Balan Fernandes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/25930-1 - Caracterização de dispersões lipídicas de interesse biológico: estruturas e interações
• Beneficiário: Maria Teresa Moura Lamy
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50983-3 - INCT 2014: fluidos complexos
• Beneficiário: Antonio Martins Figueiredo Neto
• Modalidade de apoio: Auxílio à Pesquisa - Temático