Identification, isolation and bioactivity assessment of a bioactive peptide QUB-2339 from the skin secretion of the Hainan sucker frog, Amolops hainanensis

  • Xuyang Lou

Student thesis: Masters ThesisMaster of Philosophy


Many compounds in the skin secretion of the frogs are very significant for their survivals, which could protect them from both many diseases and attacks from microorganisms and predators. And the bioactive peptides in the secretions play very important and inevitable roles to these functions. Lots of peptides have very potent abilities to inhibit the growth of bacteria and fungi. And the mechanisms of the peptides may be related to their physiochemical properties. With their complicated mechanisms, it is not very easy for the microorganisms to generate resistance to the peptides. So they could be developed as new antibiotics to cure many diseases. Moreover, many peptides display anticancer functions against tumour cells.

In this thesis, a bioactive peptide QUB-2339 was identified from the skin secretion of Hainan sucker frog, Amolops hainanensis. Then this peptide was tested by many bioassays. QUB-2339 showed antimicrobial activity against S. aureus (ATCC10788) with Minimum inhibitory concentration (MIC) of 8 μM. And the MBC value of it against S. aureus was 16 μM. But it didn’t show obviously inhibitory activity against E.coli (CRM8739) and C.albicans (ATCC10231) even at the concentration of 512 μM. Furthermore, QUB-2339 also had anti-cancer activity at 100 μM against lung cancer cell line (NCI-H838). However, the haemolytic rate of QUB-2339 was relatively high, which was more than 10%, when the concentration was above 16 μM. So it needs to be modified to decrease its toxicity before further development progresses.
Date of AwardDec 2020
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorLei Wang (Supervisor), Mei Zhou (Supervisor) & Chengbang Ma (Supervisor)

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