Discovery and in vitro evaluation of the peptide, QUB-2667, from the frog skin secretion of Amolops Loloensis

Abstract

Due to the abundance of bioactive substances in their skin, frogs have been the subject of research in the hunt for novel compounds with biological functions. Nature has been recognised as the richest source of novel treatments. Numerous pharmacological and antimicrobial peptides (AMPs) have been discovered and effectively extracted from amphibian skin and related secretions. Moreover, some of these peptides have been identified as remarkable new therapeutic candidates. 

The investigation of an AMP from the protective skin secretions of Amolops loloensis was the main objective of this work. Following the identification of the precursor structure by molecular cloning, the amino acid sequence of the mature peptide (FLPMLAGLAANFLPELFCKITKKC) was deduced from the results of an NCBI BLAST search and a CLUSTAL OMEGA sequence alignment.

After the peptide was produced by solid phase peptide synthesis, it was tested in many biological experiments. In the antimicrobial experiment, the synthesised peptide exhibited a rather obvious inhibitory activity against S. aureus, E. coli and C. albicans with MIC values of 4 μM, 16 μM and 16 μM, respectively. Depending on the HC50 value of 14.64 μM, the peptide also showed cytotoxicity against horse red blood cells. In view of IC50 (9.253 μM), the peptide exhibited anticancer activity against lung cancer cell lines.

Thesis is embargoed until 31 December 2029.

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