QUB-2577: A Bioactive Peptide from Pickerel Frog (Rana palustris) Skin Secretion

  • Weiyue Xu

Student thesis: Masters ThesisMaster of Philosophy


The skin of a frog is an important organ with a complex structure, which can play an important role not only in developing adaptation to the complex environment but also in preventing infection by microorganisms. Skin secretion of frogs contains a large number of antimicrobial peptides (AMPs) and they are considered as a promising source of antibiotic alternatives.
In this thesis, the peptide QUB-2577 was identified by "shotgun" cloning of precursor-encoding cDNA derived from the skin secretion of Rana palustris. By applying solid-phase synthesis (SPPS), the peptide was synthesised. After purification, its antimicrobial, anticancer and other biological activities were examined. The QUB-2577 was found to process broad-spectrum antimicrobial activity. It can inhitbit the growth of Gram-negative bacteria E.coil (MIC = 32 µmol/L), Gram-positive bacteria S.aureus (MIC = 4 µmol/L), and the yeast C.albicans (MIC = 64 µmol/L). The QUB-2577 was also found to exhibit anticancer activity against U251-MG, H157, PC-3 cell lines at the concentration of 10-4 M, but the anticancer effect of the peptide decreased dramatically when the concentration was lower than 10-5 M. In the meantime, its haemolytic effect was found to be relatively high.
Date of Award24 Aug 2018
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorTianbao Chen (Supervisor)

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