Molecular cloning, structural characterisation and functional study of bioactive peptides from amphibian skin secretion

  • Yuqing Chen

Student thesis: Doctoral ThesisDoctor of Philosophy


Amphibians make a tight relationship between land and water as they have to protect themselves from various situations and survive by producing defensive skin chemicals, including alkaloids, proteins and peptides. In recent years, research on peptides from the skin secretion of frogs has attracted much attention in the fields of protease inhibitor peptides and antimicrobial peptides. In this study, the skin secretion of two frogs, Amolops hainanensis and Odorrana versabilis, were obtained by use of electrical stimulation. Afterwards, ‘shotgun’ cloning was applied using 3’RACE PCR to obtain full length nucleotide sequence that encoded the open reading frames of peptide biosynthetic precursors. Three putative peptides were identified by cloning (Kunitzin-AH, QUB-1617, QUB-1629), and each was confirmed by MALDI-TOF mass spectrometry and RPHPLC, for mass confirmation and purification. Further studies on these three peptides were conducted, including their bioactivity profiling, structure-activity relationships and rational design analogues.
Date of AwardJul 2021
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorLei Wang (Supervisor), Xinping Xi (Supervisor), Tianbao Chen (Supervisor) & Mei Zhou (Supervisor)


  • Serine protease inhibitor
  • Kunitz inhibitor
  • structure modelling
  • molecular docking
  • antimicrobial peptide

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