QUB-2614: A bioactive peptide from the defensive skin secretion of Odorrana schmackeri

  • Ming Sun

Student thesis: Masters ThesisMaster of Philosophy

Abstract

Currently, more attention than ever before is being paid to the skin secretions of amphibians. There is no doubt that the skin secretions of amphibians play an important role in their daily life as a method of chemical defence. In recent biomedical research studies, these secretions have been shown to contain biologically-active compounds, such as anti-microbial peptides (AMPs) and anticancer peptides (ACPs), which are used by biomedical researchers as a source of potential novel drug leads or pharmacological tools.

In this thesis, an AMP was identified in the skin secretion of Odorrana schmackeri through "shotgun" cloning of biosynthetic precursor-encoding cDNA. Online BLAST sequence alignment analysis was used to identify the mature peptide domain, -FLPLFASLAANLLPKIICKIAKKC, and the peptide was named QUB-2614. It’s computed molecular mass was confirmed by MALDI-TOF mass spectrometry, then QUB-2614 was chemically synthesised by the method of solid phase peptide synthesis (SPPS) and purified by reverse phase-HPLC.

Functional studies showed that QUB-2614 displayed antimicrobial activity against the Gram-negative bacterium, Escherichia (E.) coli, the Gram-positive bacterium, Staphylococus (S.) aureus, and the yeast, Candida (C.) albicans. However, it possessed relatively high haemolytic activity. Furthermore, QUB-2614 was found to have significant growth inhibitory effects on MB435s, H157, U251MG and PC-3 human cancer cell lines.
Date of Award17 Aug 2017
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorTianbao Chen (Supervisor), Mei Zhou (Supervisor), Lei Wang (Supervisor), Yuxin Wu (Supervisor) & Christopher Shaw (Supervisor)

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