A Bioactive Peptide QUB2177 from the Defensive Skin Secretion of the Frog, Odorrana livida

  • Xin He

Student thesis: Masters ThesisMaster of Philosophy


Amphibian skin secretions have been reported to be unique sources of biologically-active peptides. It has been generally approved that the defensive peptides derived from amphibian skin secretions could be grouped into three broad types in accordance with their established biological effects, including antimicrobials, protease inhibitors and those with pharmacological activities.

In this study, a lividin-9b peptide named QUB-2177 (SRVVKCIGFRPGSPDSRQSC), which was named after its molecular mass, was identified from defensive skin secretion of the Large Chinese Odorous frog, Rana (Odorrana) livida using modern molecular cloning techniques. Subsequently, QUB-2177 was chemically-synthesised bymeans of solid phase peptide synthesis and structurally-characterised by application of MALDI-TOF MS. After reverse phase HPLC purification, the synthetic replicate of QUB-2177 was evaluated for its biological effect through functional assays. The results showed that QUB-2177 possessed neither significant antimicrobial nor haemolytic activity on horse erythrocytes. Besides, similar negative results were also found in the assessments of anti-cancer activity, trypsin inhibitory activity and smooth muscle-relaxing activity. The biological actions of this peptide thus remain to be established and it may represent a novel prototype peptide.
Date of Award30 Aug 2017
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorYuxin Wu (Supervisor), Mei Zhou (Supervisor), Lei Wang (Supervisor) & Tianbao Chen (Supervisor)

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