Identification and activity assessment of a bioactive peptide, QUB-2013, from the skin secretion of the Broad-folded Frog, (Phyllomedusa hypochondrialis)

Phylloseptins are a class of peptides produced from frog skin with an active structural sequence that displays antmicrobial efficacy in vitro against the E.coli, S.aureus and C.albicans.<br><br>In the current study, a peptide (FLSLIPTAINAVSALAKHF-NH2), named QUB-2013, was discovered in Phyllomedusa hypochondrialis skin secretion by use of molecular cloning, and the crude peptide was subsequently obtained by solid phase synthesis and purified by reverse phase HPLC.

MALDI-TOF MS was used to confirm the molecular mass, and a number of bioassays were performed on QUB-2013. As a result, QUB- 2013 was found to have anticancer cell activity and no appreciable cytotoxicity to horse red blood cells at concentrations less than 512 µM. Meanwhile, QUB- 2013 displayed antibacterial activity against Candida albicans below 256 µM and against E. coli and S. aureus below 128 µM. Furthermore, QUB-2013, in an MTT assay, was active at a concentration of 200 µM against NCI-H838 cancer .<br><br><i>Thesis is embargoed until 31 December 2028.</i>