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

Abstract

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.
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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