Identification and activity assessment of a bioactive peptide QUB-2995 from the skin secretion of the broad-folded Frog (Hylarana Latouchii)

  • Jingjing Mao

Student thesis: Masters ThesisMaster of Philosophy


Abstract Innate immunity is a crucial composition in vertebrates. There are three components of innate immunity: physical, humoral, and cell-mediated. Among these three sections, the antimicrobial peptides (AMPs) from humoral innate immunity, are a popular research area and have been paid much attention. They have no high specificity and can attack bacteria and kill them within minutes. At the same time, some can also damage the membranes of host cells. However, as the rapid growth in antimicrobial resistance (AMR) is very serious now, responsible for an estimated 700,000 deaths each year, the exploration of AMPs as novel solutions to this has become of the utmost importance.

In this study, a novel AMP was discovered in the skin secretion of the Asian frog, Hylarana latouchii and was named, QUB2995, (GAFGDFLKGAAKKAGLKILSIAQCKLSGTC). This AMP belongs to the brevinin-2 family. It has broad-spectrum antimicrobial activities and can kill Staphylococcus aureus, Escherichia coli and Candida albicans, with MICs of 16 µM, 16 µM and 64 µM, respectively. Also, it can kill cells of a prostate cancer cell line at a concentration of 1 × 10-4 µM. So the peptide appears to be a perfect AMP against bacteria and yeast and is active against cancer cells so it could be a potential lead compound for drug development.

However, it has inherent haemolytic activity beginning at a concentration of 32 µM. Hence, it would be necessary to modify the peptide to decrease this in order to make it more suitable for applications in the clinic.
Date of AwardDec 2020
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorLei Wang (Supervisor) & Mei Zhou (Supervisor)

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