Identification and characterisation of a bioactive peptide, namely QUB-2624, from the skin secretion of the Australian green tree frog, Litoria caerulea

This study focused on the identification, characterisation, and functional evaluation of QUB-2624, a bioactive peptide isolated from the skin secretion of the Australian green tree frog, Litoria caerulea. Molecular cloning techniques were employed to obtain the peptide sequence, which was then synthesised for functional studies following HPLC purification.

The results revealed that QUB-2624 displayed differential inhibitory effects on tested microorganisms. The minimum inhibitory concentration (MIC) values of QUB-2624 against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were both determined as 16 µM. Interestingly, QUB-2624 exhibited stronger inhibitory activity against E. coli compared to S. aureus at a concentration of 8 µM. Moreover, it demonstrated higher bactericidal activity against E. coli than S. aureus, with minimum bactericidal concentration (MBC) values of 16 µM and 32 µM, respectively.