Identification and functional evaluation of an antimicrobial peptide isolated from the skin secretion of the large Chinese odorous frog, Odorrana livida

Abstract

Amphibian skin secretions have been demonstrated to be a source of biologically active peptides that are unique in their composition. It has been generally accepted that the defensive peptides derived from amphibian skin secretions can be grouped into three broad categories in accordance with their established biological effects, including antimicrobials, protease inhibitors and those with pharmacological activities.

In this study, a peptide from the lividin family, designated QUB-2193 (SRVVKCIGFRPGSPDSRQSC), was identified from defensive skin secretion of the large Chinese odorous frog, Odorrana livida, using ‘shotgun’ cloning techniques. Subsequently, QUB-2193 was chemically synthesised via SPPS and structurally characterised by the application of MALDI-TOF MS. Following RP-HPLC purification, the synthetic replicate of QUB-2193 was subjected to functional assays to evaluate its biological effect. The results demonstrated that QUB-2193 exhibited no significant antimicrobial or haemolytic activity on horse erythrocytes. Furthermore, similar negative results were also found in the assessments of antiproliferative activity. The biological actions of this peptide remain to be established, and it has the potential to improve bioactivities by some modification.

Thesis is embargoed until 31 December 2029.

Date of Award	Dec 2024
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Lei Wang (Supervisor), Tianbao Chen (Supervisor) & Mei Zhou (Supervisor)