The family Pipidae comprises the genera Hymenochirus, Pipa, Pseudhymenochirus, Silurana, and Xenopus but phylogenetic relationships within the family are unclear. Peptidomic analysis of norepinephrine-stimulated skin secretions from Pseudhymenochirus merlini Chabanaud, 1920, the single species within the genus Pseudhymenochirus, led to identification of 13 host-defense peptides with antimicrobial activity. Two peptides (hymenochirin-1Pa and -1Pb) show structural similarity to hymenochirin-1B from Hymenochirus boettgeri and eight peptides (hymenochirin-5Pa, -5Pb, -5Pc, -5Pd, -5Pe, -5Pf, 5Pg and -5Ph) are structurally similar to each other and to hymenochirin-5B from H. boettgeri. Two peptides differing by a single amino acid (IKIPSFFRNILKKVGKEAVSLM/I AGALKQS), termed pseudhymenochirin-1Pa and -1Pb, and pseudhymenochirin-2Pa (GIFPIFAKLLGKVIKVASSLISKGRTE) do not resemble host-defense peptides previously isolated from pipid frogs. Hymenochirin-5Pe was the most abundant peptide in the secretions and hymenochirin-1Pa the most potent against Staphylococcus aureus (MIC = 2.5 μM) and Escherichia coli (MIC = 10 μM). The data support a close phylogenetic relationship between Hymenochirus and Pseudhymenochirus that is distinct from the Xenopodinae (Xenopus + Silurana) clade with Pipa sister-group to all other extant pipids.
|Number of pages||6|
|Journal||Comparative Biochemistry and Physiology - Part D: Genomics and Proteomics|
|Publication status||Published (in print/issue) - 2013|
Bibliographical noteFunding Information:
This work was supported by the Terry Fox Fund for Cancer Research , a Faculty Support Grant and a University Research Grant from U.A.E. University . The authors thank Noémio Sousa for supplying the captive-bred frogs.
- Antimicrobial peptide
- Frog skin