A Novel Ocellatin-P1 Isoform from Leptodactylus labyrinthicus Frog Skin Secretion: Purification, Biological Properties and Three-Dimensional Structure
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Le résumé fourni par la source
A novel ocellatin-P1 isoform was isolated and purified from the skin secretion of the pepper frog Leptodactylus labyrinthicus. The crude skin secretion was fractionated by reversed-phase high-performance liquid chromatography (RP-HPLC) using a C8 column and the peptide was subsequently purified on a reversed-phase C18 column. Ocellatin-LB3 (as this isoform was named) was chemically sequenced by Edman degradation. This peptide is a linear C-terminally amidated molecule composed of 25 amino acid residues: 1GLLDTLKGAAKNVVGGLASKVMEKL25-NH2. Synthetic ocellatin-LB3 was active against Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa and inactive against Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis. In addition, the peptide reduced the Trypanosoma cruzi infection in L6 cells. At 64 µM it did not reduce erythrocytes or polymorphonuclear leukocytes, but did reduce mononuclear leukocyte counts, as detected by flow cytometry. No hemolytic activity was observed in red blood cells even at 128 µM. The peptide exhibited limited antiproliferative activity against MCF-7 and HeLa tumor cells at 128 µM. Pre-incubation with the peptide appeared to enhance N-formylmethionine-leucyl-phenylalanine (fMLP)-induced migration, indicating a potential additive or synergistic effect on human neutrophils. The three-dimensional structure of ocellatin-LB3 was investigated by circular dichroism (CD) and nuclear magnetic resonance (NMR). In the presence of sodium dodecyl sulfate (SDS), the peptide adopts an α-helical structure spanning residues Leu3–Lys24, which remains largely preserved even at 95 °C. NMR Hydrogen/Deuterium (H/D) exchange experiments suggest that ocellatin-LB3 adopts a preferential orientation when interacting with SDS micelles. Based on the similarity among ocellatins, and on the physicochemical and structural properties of this peptide, a possible membrane-mediated mode of action is proposed, although this remains to be experimentally validated.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- A Novel Ocellatin-P1 Isoform from Leptodactylus labyrinthicus Frog Skin Secretion: Purification, Biological Properties and Three-Dimensional Structure
- Date Crossref
- 20/04/2026
- Éditeur
- MDPI AG
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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Universidade de Brasília Instituto de Ciências Biológicas pays non établi dans la noticeUniversité ou école supérieure
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Universidade Federal de Goiás Instituto de Química pays non établi dans la noticeUniversité ou école supérieure
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Rede de Química e Tecnologia pays non établi dans la noticeOrganisation à but non lucratif
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Universidade Estadual Paulista (Unesp) pays non établi dans la noticeUniversité ou école supérieure
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Instituto de Saúde pays non établi dans la noticeOrganisme public
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Instituto Butantan Unidade de Sequenciamento de Peptídeos e Proteínas pays non établi dans la noticeStructure de recherche
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Universidade Estadual de São Paulo Instituto de Química pays non établi dans la noticeUniversité ou école supérieure
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Laboratório Central de Saúde Pública (LACEN) pays non établi dans la noticeInstitution
Instituto de Ciências Biológicas — Universidade de Brasília, Instituto de Química — Universidade Federal de Goiás et Rede de Química e Tecnologia, avec 5 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.