Isolation and identification of an antimicrobial peptide with high anticancer activity and selectivity, QUB-2584 from the skin secretion of Litoria caerulea

Abstract

Large quantities of antimicrobial peptides derived from the frog skin secretion have the potential to be therapeutic drugs due to their bioactivities. Their various and complex structural classification, physical-chemical properties, and mechanism contributing to their bioactivities have been discovered and well understood. Here, we focus on a bioactive peptide named QUB-2584 derived from the skin secretion of Litoria caerulea, which is an Australian frog. Molecular cloning was used to confirm its sequence. Then the peptide was chemically synthesised by Solid Phase Peptide Synthesis, purified by RP-HPLC, and then analysed by MALDI-TOF MS to identify the peptide. Finally, QUB-2584 was tested by biological assays, it has shown significant antimicrobial activities against S. aureus, E. coli, and C. albicans with MIC at 2, 8, and 32 μM, respectively. There was great anticancer activity of it against the cell line U251MG especially at concentration of 10 -4 M. Besides, it showed haemolytic activity with 36.6 % haemolysis at 32 μM. Hence, the peptide deserved great attention as potential therapeutics due to its great bioactivity and is expected to be optimised to be a good drug candidate.

Date of Award	Dec 2020
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Mei Zhou (Supervisor) & Lei Wang (Supervisor)