: A bioactive peptide from the skin secretion of the south American orange-legged leaf frog (phyllomedusa hypochondrialis)

  • Yatong Xia

Student thesis: Masters ThesisMaster of Philosophy


As a consequence of the widespread use of antimicrobial agents, not only in the clinic but also in agriculture, veterinary medicine and even animal husbandry, antibiotic resistance emerged and gradually became one of the most evident crises during the past several decades. Antimicrobial peptides (AMPs) now represent an important alternative strategy for treating antibiotic resistance as well as a new source of potential anticancer drugs, thus these peptides have been attracting increased research attention. The skin secretions of amphibians contain abundant peptides and most of these have pronounced bioactivities.
In this thesis, a bioactive peptide named QUB-2410 was successfully identified from the venom of the skin of the South American orange-legged leaf frog (Phyllomedusa hypocondrialis) by “shotgun” cloning. This peptide was then synthesised using solid-phase peptide synthesis and then analysed by HPLC and MALDI-TOF MS to determine the purity and authenticity of the molecular mass. The results showed that the chemically synthesized peptides exhibited strong antibacterial activity against E. coli, S. aureus and C. albicans with minimum inhibitory concentration(MIC) values of 8 µM, 8 µM and 32 µM, respectively. Additionally, QUB-2410 failed to inhibit the proliferation of cancer cells against PC-3, H157, U251MG and MCF-7 at the concentration of 10-5 M. Moreover, QUB-2410 also showed relatively weak haemolytic activity. QUB 2410 may have the potential to be developed into a novel antibiotic drug.
Date of AwardJul 2018
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorYuxin Wu (Supervisor), Tianbao Chen (Supervisor), Christopher Shaw (Supervisor), Mei Zhou (Supervisor) & Lei Wang (Supervisor)

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