Identification and characterisation of a novel antimicrobial peptide from the defensive skin secretion of the Heilongjiang brown frog, Rana amurensis

Abstract

Antimicrobial peptides (AMPs) are one of the research hotspots because of the special mechanisms they have which make them less prone to inducing resistance. However, cytotoxicity limits the development of antimicrobial peptides. It has been proven that many structural parameters have important effects on the antimicrobial activity of the peptide. So, an increasing number of researchers have begun to pay attention to the relationship of structure and activity of peptides. The amphibian skin secretion is a huge resource for AMPs. In this study, a novel AMP (QUB-2944) from the defensive skin secretion of the Heilongjiang Brown Frog, Rana amurensis, has been identified and characterised. The nucleotide sequence and opening-reading frame amino acid residues of the novel peptide QUB-2944 were obtained by the combination of molecular cloning and Sanger sequencing. Then bioactivity of the peptide was evaluated through using antimicrobial assays, antiproliferative assays and haemolysis assay. It was found to inhibit the growth of E. coli (MIC=2µM), S. aureus (MIC=16µM), and C. albicans (MIC=64µM). It also possessed antiproliferative activity against NCI-H838 (IC50=4.123µM) and strong haemolytic activity (HC50=14.21 µM). The results showed that QUB-2944 is a brevinin-2 peptide, which has value to be further developed as a drug candidate in the future.

Thesis embargoed until 31 December 2026.

Date of Award	Dec 2021
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Lei Wang (Supervisor), Mei Zhou (Supervisor), Tianbao Chen (Supervisor) & Xinping Xi (Supervisor)