The skin of amphibians is rich in bioactive substances among which are those called bioactive peptides. The bioactive peptides could play a key role in new drug development. In this thesis, a bioactive peptide named QUB-1966, was isolated and characterised from the skin secretion of the Chinese Ranidae frog, Odorrana versabilis. The peptide consisted of 21 amino acid residues, GLLSGILGAGKHIVCGLSGLC. Following molecular cloning of peptide precursor encoding cDNA, the structure of QUB-1966 was unequivocally identified. By means of solid phase peptide synthesis, a replicate of QUB-1966 was synthesised and the biological activity of this synthetic peptide was further evaluated through multiple biological assays. These found that QUB-1966 exhibited moderate antimicrobial effects against the Gram-negative bacterium, Escherichia coli (E. coli), the Gram-positive bacterium, Staphylococcus aureus (S. aureus) and the yeast, Candida albicans (C. albicans) with minimal inhibitory concentrations of 128 μM, 64 μM and 128 μM, respectively. Unfortunately, QUB-1966 has no obvious anti-proliferation activity against MB453s, H157, U251MG and PC-3 cancer cells at the concentration of 10 μM. In addition, QUB-1966 demonstrated no haemolytic activity. These data illustrate that amphibian skin secretion is a promising source for discovery of novel peptides, some of which may provide new insights for drug development.
|Date of Award||08 Sep 2017|
- Queen's University Belfast
|Supervisor||Christopher Shaw (Supervisor), Tianbao Chen (Supervisor), Lei Wang (Supervisor) & Chengbang Ma (Supervisor)|