Peptidomic analysis of skin secretions of the Mexican burrowing toad Rhinophrynus dorsalis (Rhinophrynidae): insight into the origin of host-defense peptides within the Pipidae and characterization of a proline-arginine-rich peptide

JM Conlon, L Guilhaudis, J Leprince, L Coquet, ML Mangoni, S Attoub, JD King

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

The Mexican burrowing toad Rhinophrynus dorsalis is the sole extant representative of the Rhinophrynidae. United in the superfamily Pipoidea, the Rhinophrynidae is considered to be the sister-group to the extant Pipidae which comprises Hymenochirus, Pipa, Pseudhymenochirus and Xenopus. Cationic, α-helical host-defense peptides of the type found in Hymenochirus, Pseudhymenochirus, and Xenopus species (hymenochirins, pseudhymenochirins, magainins, and peptides related to PGLa, XPF, and CPF) were not detected in norepinephrine-stimulated skin secretions of R. dorsalis. Skin secretions of representatives of the genus Pipa also do not contain cationic α-helical host-defense peptides which suggests, as the most parsimonious hypothesis, that the ability to produce such peptides by frogs within the Pipidae family arose in the common ancestor of (Hymenochirus+Pseudhymenochirus)+Xenopus after divergence from the line of evolution leading to extant Pipa species. Peptidomic analysis of the R. dorsalis secretions led to the isolation of rhinophrynin-27, a proline-arginine-rich peptide with the primary structure ELRLPEIARPVPEVLPARLPLPALPRN, together with rhinophrynin-33 containing the C-terminal extension KMAKNQ. Rhinophrynin-27 shows limited structural similarity to the porcine multifunctional peptide PR-39 but it lacks antimicrobial and cytotoxic activities. Like PR-39, the peptide adopts a poly-l-proline helix but some changes in the circular dichroism spectrum were observed in the presence of anionic sodium dodecylsulfate micelles consistent with the stabilization of turn structures.
Original languageEnglish
JournalPeptides
VolumeN/A
Early online date23 Sept 2017
DOIs
Publication statusPublished online - 23 Sept 2017

Keywords

  • Frog skin
  • Rhinophrynidae
  • Pipidae
  • Host-defense
  • Antimicrobial
  • PR-39

Fingerprint

Dive into the research topics of 'Peptidomic analysis of skin secretions of the Mexican burrowing toad Rhinophrynus dorsalis (Rhinophrynidae): insight into the origin of host-defense peptides within the Pipidae and characterization of a proline-arginine-rich peptide'. Together they form a unique fingerprint.

Cite this