Dissecting the mechanism of action of actinoporins. Role of the N-terminal amphipathic alpha-helix in membrane binding and pore activity of sticholysins I and II

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dc.contributor.authorCarretero, Gustavo P. B.
dc.contributor.authorVicente, Eduardo F. [UNESP]
dc.contributor.authorCilli, Eduardo M. [UNESP]
dc.contributor.authorAlvarez, Carlos M.
dc.contributor.authorJenssen, Havard
dc.contributor.authorSchreier, Shirley
dc.contributor.institutionUniversidade de São Paulo (USP)
dc.contributor.institutionRoskilde Univ
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.contributor.institutionUniv Havana
dc.date.accessioned2018-11-26T17:55:15Z
dc.date.available2018-11-26T17:55:15Z
dc.date.issued2018-08-30
dc.description.abstractActinoporins sticholysin I and sticholysin II (St I, St II) are proposed to lyse model and biomembranes via toroidal pore formation by their N-terminal domain. Based on the hypothesis that peptide fragments can reproduce the structure and function of this domain, the behavior of peptides containing St I residues 12-31 (StI(12)(-)(31)), St II residues 11-30 (StII(11)(-)(30)), and its TOAC-labeled analogue (N-TOAC-StII(11)(-)(30)) was examined. Molecular modeling showed a good match with experimental structures, indicating amphipathic alpha-helices in the same regions as in the toxins. CD spectra revealed that the peptides were essentially unstructured in aqueous solution, acquiring alpha-helical conformation upon interaction with micelles and large unilamellar vesicles (LUV) of variable lipid composition. Fluorescence quenching studies with NBD-containing lipids indicated that N-TOAC-StII(11)(-)(30)'s nitroxide moiety is located in the membranes polar head group region. Pyrene-labeled phospholipid inter-leaflet redistribution suggested that the peptides form toroidal pores, according to the mechanism of action proposed for the toxins. Binding occurred only to negatively charged LUV, indicating the importance of electrostatic interactions; in contrast the peptides bound to both negatively charged and zwitterionic micelles, pointing to a lesser influence of these interactions. In addition, differences between bilayers and micelles in head group packing and in curvature led to differences in peptide-membrane interaction. We propose that the peptides topography in micelles resembles that of the toxins in the toroidal pore. The peptides mimicked the toxins permeabilizing activity, St II peptides being more effective than StI(12)(-)(31). To our knowledge, this is the first demonstration that differences in the toxins N-terminal amphipathic alpha-helix play a role in the difference between St I and St II activities.en
dc.description.affiliationUniv Sao Paulo, Inst Chem, Dept Biochem, Sao Paulo, Brazil
dc.description.affiliationRoskilde Univ, Dept Sci & Environm, Roskilde, Denmark
dc.description.affiliationState Univ Sao Paulo, Fac Sci & Engn, Tupa, Brazil
dc.description.affiliationState Univ Sao Paulo, Inst Chem, Araraquara, Brazil
dc.description.affiliationUniv Havana, Ctr Prot Studies, Havana, Cuba
dc.description.affiliationUnespState Univ Sao Paulo, Fac Sci & Engn, Tupa, Brazil
dc.description.affiliationUnespState Univ Sao Paulo, Inst Chem, Araraquara, Brazil
dc.description.sponsorshipFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.description.sponsorshipConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.description.sponsorshipCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.format.extent23
dc.identifierhttp://dx.doi.org/10.1371/journal.pone.0202981
dc.identifier.citationPlos One. San Francisco: Public Library Science, v. 13, n. 8, 23 p., 2018.
dc.identifier.doi10.1371/journal.pone.0202981
dc.identifier.fileWOS000443388900059.pdf
dc.identifier.issn1932-6203
dc.identifier.urihttp://hdl.handle.net/11449/164598
dc.identifier.wosWOS:000443388900059
dc.language.isoeng
dc.publisherPublic Library Science
dc.relation.ispartofPlos One
dc.relation.ispartofsjr1,164
dc.rights.accessRightsAcesso aberto
dc.sourceWeb of Science
dc.titleDissecting the mechanism of action of actinoporins. Role of the N-terminal amphipathic alpha-helix in membrane binding and pore activity of sticholysins I and IIen
dc.typeArtigo
dcterms.rightsHolderPublic Library Science
unesp.author.lattes6380599830437803[2]
unesp.author.orcid0000-0002-9154-3574[2]

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