Study of the mechanism of action of anoplin, a helical antimicrobial decapeptide with ion channel-like activity, and the role of the amidated C-terminus
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Data
2008-06-01
Autores
Dos Santos Cabrera, Marcia Perez
Arcisio-Mirandaa, Manoel
Broggio Costa, Sabrina Thais [UNESP]
Konno, Katsuhiro
Ruggiero, José Roberto [UNESP]
Procopio, Joaquim
Neto, Joao Ruggiero [UNESP]
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Editor
John Wiley & Sons Ltd
Resumo
Anoplin, an antimicrobial, helical decapeptide from wasp venom, looses its biological activities by mere deamidation of its C-terminus. Secondary structure determination, by circular dichroism spectroscopy in amphipathic environments, and lytic activity in zwitterionic and anionic vesicles showed quite similar results for the amidated and the carboxylated forms of the peptide. The deamidation of the C-terminus introduced a negative charge at an all-positive charged peptide, causing a loss of amphipathicity, as indicated by molecular dynamics simulations in TFE/water mixtures and this subtle modification in a peptide's primary structure disturbed the interaction with bilayers and biological membranes. Although being poorly lytic, the amidated form, but not the carboxylated, presented ion channel-like activity on anionic bilayers with a well-defined conductance step; at approximately the same concentration it showed antimicrobial activity. The pores remain open at trans-negative potentials, preferentially conducting cations, and this situation is equivalent to the interaction of the peptide with bacterial membranes that also maintain a high negative potential inside. Copyright (C) 2007 European Peptide Society and John Wiley & Sons, Ltd.
Descrição
Palavras-chave
Anoplin, Antimicrobial peptide, Lytic activity, Ion channel, Pore activity, Peptide-membrane interaction, Molecular dynamics
Como citar
Journal of Peptide Science. Chichester: John Wiley & Sons Ltd, v. 14, n. 6, p. 661-669, 2008.