QUB-1453: A Bioactive Peptide from the Defensive Skin Secretion of Rana amurensis

Abstract

Amphibian skin secretion is one of the richest sources for antimicrobial peptides (AMPs) which have potent bioactivity and pharmaceutical value for new drug development. In this thesis, QUB-1452, an AMP, was isolated and characterised from the skin secretion of Rana amurensis. The peptide is composed of 13 amino acid residues, FLPVLISLIGRLL, and is C-terminally amidated. The structure and functions of QUB-1452 were identified via nucleotide/amino acid sequencing and bioactivity analyses. The results showed that QUB-1452 had relatively strong antimicrobial activity against S. aureus (Staphylococcus aureus) and C. albicans (Candida albicans) with minimal inhibitory concentrations of 8 µmol/L and 16 µmol/L respectively, while it had little effect on the growth of E. coli (Escherichia coli). In addition, QUB-1452 had high haemolytic activity at high concentrations, whereas the haemolytic activity was relatively low at the minimal inhibitory concentrations against S. aureus and C. albicans at 3.3% and 6.6%, respectively. Moreover, the peptide had no effect on cancer cells. These data demonstrate the potential of amphibian skin secretions to provide novel natural peptide templates for biological evaluation.

Date of Award	29 Aug 2017
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Christopher Shaw (Supervisor), Tianbao Chen (Supervisor), Yuxin Wu (Supervisor), Mei Zhou (Supervisor) & Lei Wang (Supervisor)