The interfacial properties of the peptide Polybia-MP1 and its interaction with DPPC are modulated by lateral electrostatic attractions

Autor(es)

Alvares, Dayane S. ^[1] ; Laura Fanani, Maria ^[2] ; Ruggiero Neto, Joao ^[1] ; Wilke, Natalia ^[2]

Afiliação do(s) autor(es)

^[1] UNESP Sao Paulo State Univ, IBILCE, Dept Phys, Sao Jose Do Rio Preto, SP - Brazil

^[2] Univ Nacl Cordoba, Fac Ciencias Quim, Dept Quim Biol, Ctr Invest Quim Biol Cordoba CIQUIBIC, CONICET, RA-5000 Cordoba - Argentina

• Tipo de documento: Artigo Científico
• Fonte: BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES; v. 1858, n. 2, p. 393-402, FEB 2016.
• Citações Web of Science: 12

Resumo

Polybia-MP1 (IDWKKLLDAAKQIL-NH2), extracted from the Brazilian wasp Polybia paulista, exhibits a broad-spectrum bactericidal activity without being hemolytic and cytotoxic. In the present study, we analyzed the surface properties of the peptide and its interaction with DPPC in Langmuir monolayers. Polybia-MP1 formed stable monolayers, with lateral areas and surface potential values suggesting a mostly alpha-helical structure oriented near perpendicular to the membrane plane. In DPPC-peptide mixed monolayers, MP1 co-crystallized with the lipid forming branched domains only when the subphase was pure water. On subphases with high salt concentrations or at acidic or basic conditions, the peptide formed less densely packed films and was excluded from the domains, indicating the presence of attractive electrostatic interactions between peptides, which allow them to get closer to each other and to interact with DPPC probably as a consequence of a particular peptide arrangement. The residues responsible of the peptide-peptide attraction are suggested to be the anionic aspartic acids and the cationic lysines, which form a salt bridge, leading to oriented interactions in the crystal and thereby to branched domains. For this peptide, the balance between total attractive and repulsive interactions may be finely tuned by the aqueous ionic strength and pH, and since this effect is related with lysines and aspartic acids, similar effects may also occur in other peptides containing these residues in their sequences. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 12/08147-8 - Estudo da formação de domínios em membranas modelo induzidos por peptídeos antimicrobianos e sua ação interfacial
• Beneficiário: Dayane dos Santos Alvares
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 11/11640-5 - Interação de peptídeos líticos e membranas modelo: ação interfacial e indução de domínios lipídicos
• Beneficiário: João Ruggiero Neto
• Modalidade de apoio: Auxílio à Pesquisa - Regular