Insecticidal activity of a recombinant knottin peptide from Loxosceles intermedia venom and recognition of these peptides as a conserved family in the genus.
Insect Mol Biol
; 26(1): 25-34, 2017 02.
Article
em En
| MEDLINE
| ID: mdl-27743460
ABSTRACT
Loxosceles intermedia venom comprises a complex mixture of proteins, glycoproteins and low molecular mass peptides that act synergistically to immobilize envenomed prey. Analysis of a venom-gland transcriptome from L. intermedia revealed that knottins, also known as inhibitor cystine knot peptides, are the most abundant class of toxins expressed in this species. Knottin peptides contain a particular arrangement of intramolecular disulphide bonds, and these peptides typically act upon ion channels or receptors in the insect nervous system, triggering paralysis or other lethal effects. Herein, we focused on a knottin peptide with 53 amino acid residues from L. intermedia venom. The recombinant peptide, named U2 -sicaritoxin-Li1b (Li1b), was obtained by expression in the periplasm of Escherichia coli. The recombinant peptide induced irreversible flaccid paralysis in sheep blowflies. We screened for knottin-encoding sequences in total RNA extracts from two other Loxosceles species, Loxosceles gaucho and Loxosceles laeta, which revealed that knottin peptides constitute a conserved family of toxins in the Loxosceles genus. The insecticidal activity of U2 -SCTX-Li1b, together with the large number of knottin peptides encoded in Loxosceles venom glands, suggests that studies of these venoms might facilitate future biotechnological applications of these toxins.
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Base de dados:
MEDLINE
Assunto principal:
Venenos de Aranha
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Diester Fosfórico Hidrolases
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Miniproteínas Nó de Cistina
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Aranha Marrom Reclusa
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Inseticidas
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article