Discovery and bioactivity assessment of a peptide QUB-1331 from the skin secretion of the Senegal Running Frog (Kassina senegalensis)

  • Yiman Liu

Student thesis: Masters ThesisMaster of Philosophy

Abstract

Since more and more antimicrobial peptides exhibited enormous potency in inhibiting the growth of microorganisms, especially bacteria and fungi, they have been regarded as alternative therapeutic reagents for various treatments in clinic.

In this research, a novel peptide QUB-1331 (FLGGLLNTLTGLL-NH2) was identified from the skin secretion of Kassina senegalensis, a Senegal running frog via “shotgun cloning” strategy. After the peptide QUB-1331 precursor-encoding cDNA was obtained, Solid Phase Peptide Synthesis (SPPS) was applied to synthesise the peptide QUB-1331. Subsequently, RPHPLC was used to separate QUB-1331 from the impure peptide at the wavelength of 214 nm. Bioactive verification found that QUB-1331 showed moderate broad-spectrum antimicrobial activity on three different microorganisms, including S. aureus (MIC=32 μM), E. coli (MIC=128 μM) and C. albicans (MIC=256 μM). The anticancer assays indicated that QUB1331 showed no significant anticancer activity towards human cancer cells. What’s more, QUB-1331 also exhibited less than 50% haemolytic activity against the horse red blood cells at the concentration up to 256 mg/L, which was regarded as the main obstacle to develop a promising candidate to substitute antibiotics. Hence, further exploration on the mechanisms of antimicrobial action and structure modification of QUB-1331 was required.
Date of AwardDec 2020
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorLei Wang (Supervisor), Mei Zhou (Supervisor) & Chengbang Ma (Supervisor)

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