The discovery of a novel peptide, QUB-2023, from Rana amurensis

  • Kun Han

Student thesis: Masters ThesisMaster of Philosophy


The abundant antimicrobial peptides (AMPs) discovered in amphibian skin secretions have raised the interest of many researchers not only because of their broad spectrum of actions against many clinically-relevant microorganisms but also their superiority over conventional antibiotics.

This investigation has led to the discovery of a novel peptide QUB-2023, from the skin secretion of Rana amurensis. This was achieved by “shotgun” cloning. Solid-phase peptide synthesis (SPPS) and Reversed-Phase High Performance Liquid Chromatography (RP-HPLC) were applied to obtain a sufficient quantity of pure peptide replicate. The primary structure of the peptide was confirmed by MALDI-TOF (matrix assisted laser desorption ionisation-time of flight) mass spectrometry. QUB-2023 displayed antimicrobial activity against three microorganisms: the Gram-positive bacterium Staphylococcus aureus, the Gram-negative bacterium Escherichia coli and the yeast Candida albicans. The minimal inhibitory concentrations against S. aureus and C. albicans were fourfold lower than that against E. coli. The minimum haemolytic concentration that caused 10% haemolysis of horse red blood cells was lower than the MICs.

It is expected that the possible further investigation of QUB-2023 will help understand the mechanism and influential parameters of amphibian skin secretion AMPs activities.
Date of Award2017
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorTianbao Chen (Supervisor), Lei Wang (Supervisor), Lei Li (Supervisor) & Mei Zhou (Supervisor)

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