Characterized analysis of peptide QUB-1433 from the skin secretion of the dark-spotted frog (Pelophylax nigromaculatus)

  • Wenjie Wang

Student thesis: Masters ThesisMaster of Philosophy


Bioactive peptide isolated from the granular glands of frog skin have been widely discovered to exhibit antimicrobial and anticancer activities. Since the antibiotic resistance has become a severe difficulty in modern therapeutic treatment, many of them have been developed into clinical application for the treatment of microbial infection and cancer.

In this thesis, a potent natural antimicrobial peptide QUB-1433 was identified and cloned from the skin secretion of Pelophylax nigromaculatus via “shotgun” cloning. According to the amino acid residues of QUB-1433, the pure peptide was synthesised and purified via solid-phase peptide synthesis and RP-HPLC. Subsequently, antimicrobial, anticancer and haemolysis assays were performed on QUB-1433 for its functional evaluation. From the results of a series of bioactive assays, QUB-1433 displayed activities of against Gram-positive bacteria and fungi (MIC values are 16 and 32 µM), but is lack in broad-spectrum of anticancer ability (MIC value is 128 µM). Moreover, QUB-1433 possesses relative low cytotoxicity towards mammalian cell. Hence the bioactivities of QUB-1433 provided new insight in the discovery of new drugs. However, the mechanisms of action and optimization of QUB-1433 still required the further exploration.

Thesis embargoed until 31st October 2024
Date of AwardDec 2019
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorTianbao Chen (Supervisor), Lei Wang (Supervisor), Mei Zhou (Supervisor) & Chengbang Ma (Supervisor)

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