title: Membrane-disruptive properties of the bioinsecticide Jaburetox-2Ec: implications to the mechanism of the action of insecticidal peptides derived from ureases.
abstract: Jaburetox-2Ec, a recombinant peptide derived from an urease isoform (JBURE-II), displays high insecticidal activity against important pests such as Spodoptera frugiperda and Dysdercus peruvianus. Although the molecular mechanism of action of ureases-derived peptides remains unclear, previous ab initio data suggest the presence of structural motifs in Jaburetox-2Ec with characteristics similar to those found in a class of pore-forming peptides. Here, we investigated the molecular aspects of the interaction between Jaburetox-2Ec and large unilamellar vesicles. Jaburetox-2Ec displays membrane-disruptive ability on acidic lipid bilayers and this effect is greatly influenced by peptide aggregation. Corroborating with this finding, molecular modeling studies revealed that Jaburetox-2Ec might adopt a well-defined beta-hairpin conformation similar to those found in antimicrobial peptides with membrane disruption properties. In addition, molecular dynamics simulations suggest that the protein is able to anchor at a polar/non-polar interface. In the light of these findings, for the first time it was possible to point out some evidence that the peptide Jaburetox-2Ec interacting with lipid vesicles promotes membrane permeabilization.
authors.affiliation: Departamento de Físico-Química, Instituto de Química, Universidade Federal do Rio de Janeiro, CT, Bloco A S410, Rio de Janeiro 21941-909, Brazil.
authors.forename: Pedro R
authors.initials: PR
authors.lastname: Barros
authors.forename: Hubert
authors.initials: H
authors.lastname: Stassen
authors.forename: Mônica S
authors.initials: MS
authors.lastname: Freitas
authors.forename: Célia R
authors.initials: CR
authors.lastname: Carlini
authors.forename: Marco A C
authors.initials: MA
authors.lastname: Nascimento
authors.forename: Cristian
authors.initials: C
authors.lastname: Follmer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D032449:Canavalia / Q000201:enzymology / Q000235:genetics; D020062:Heteroptera; D007306:Insecticides / Q000737:chemistry* / Q000494:pharmacology*; D008051:Lipid Bilayers; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D018411:Spodoptera; D053835:Unilamellar Liposomes; D014510:Urease / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D008051:Lipid Bilayers; D010940:Plant Proteins; D011994:Recombinant Proteins; D053835:Unilamellar Liposomes; D014510:Urease; C525847:jaburetox-2Ec, Canavalia ensiformis