Characterisation and bioactivity evaluation of a peptide, Odorrana-S1, from the skin secretion of the frog, Odorrana grahami

Peptides produced from amphibian skin secretion from anuran species demonstrate exceptional antibiotic effects and may ultimately play a central role as alternatives to classical antibiotics as the latter have largely lost their efficacy due to resistance acquisition by target bacteria. <br><br>In this study, the discovery of a novel peptide is described from the skin secretion of Odorrana grahami and was named Odorrana-S1.

It was successfully cloned by “shotgun” cloning and Sanger sequencing established that it was composed of 14 amino acids. Following synthesis through solid phase peptide synthesis, RP-HPLC purification and MALDI-TOF MS analysis, the peptide was deemed to be of sufficiently high purity for biofunctional analysis. After conducting a series of bioassays including MIC, MTT and haemolysis assays, Odorrana-S1 displayed MICs of >512 μM, no significant performance against cancer cells and no haemolysis of horse red blood cells. <br>Although Odorrana-S1 did not demonstrate remarkable bioactivities compared with other natural or synthetic antimicrobial peptides (AMPs), it offered a new insight into the effects of structural and physical properties on biological activity which can aid in the design of antimicrobial peptide analogues.<br><br><i>Thesis is embargoed until 31 December 2028.</i><br>