The discovery and bioactivity evaluation of a novel peptide, QUB-1925, and its modified analogue, QUB-2067, from the defensive skin secretion of the frog, Phyllomedusa coelestis

These bioactive frog skin peptides, which play a crucial role in protecting frogs from pathogenic microbes’ invasion and natural predators’ attack, are thought to be highly potential of being or providing lead compounds in the future drug development. Those frog skin antimicrobial peptides with potent activities against a broad range of microorganisms are of highest potential, due to the emergence of the multiple drug resistance issue of conventional antibiotics.<br>In this research, a novel bioactive peptide, named QUB-1925, was identified and structurally-characterised from the lyophilised skin secretion of the frog, Phyllomedusa coelestis.

The ‘shotgun’ cloning strategy was applied to obtain the peptide precursor sequence. According to the mature peptide sequence, a synthetic replicate of QUB-1925 was obtained using the solid-phase peptide synthesis (SPPS) method. Then the synthetic replicate of QUB-1925 was subjected to bioactivity and toxicity tests.