: A bioactive peptide from the frog skin secretion of Phyllomedusa palliate

  • Pengcheng Sheng

Student thesis: Masters ThesisMaster of Philosophy


Antimicrobial peptides belonging to the dermaseptin family are mainly found in phyllomedusine frogs. These peptides not only possess potent antimicrobial activity but exhibit low toxicity against eukaryotic cells. In a recent study, potent antimicrobial activity was correlated with the conserved structures and cationic amphiphilic characteristics of members of this peptide family. A dermaseptin peptide precursor was discovered here in the skin secretion of Phyllomedusa palliate, and the mature peptide was subsequently named QUB-2454. The chemically-synthesised and purified QUB-2454 showed that QUB-2454 has potent antimicrobial activity against S. aureus and E. coli with MICs at 8μM, but it is weaker against C. albicans and has no effect on tested cancer cells: U251MG, H157, PC-3 and MCF-7. This article mainly discusses its possible antimicrobial mechanism by comparing other peptides of the same family. These data indicate that QUB-2454 may represent potential candidates for next-generation antibiotics. Thus, rational design through modification of the amino acid composition, affinity, cationic charge and so on could provide an accelerated path to overcoming obstacles enroute to their possible clinical applications.
Date of AwardJul 2018
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorChristopher Shaw (Supervisor), Tianbao Chen (Supervisor), Mei Zhou (Supervisor) & Lei Wang (Supervisor)

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