Identification and functional characterisation of an antimicrobial peptide QUB-1529 from the skin secretion of the Asian frog, Hylarana guentheri

Abstract

Hylarana guentheri is a species which is widely distributed in the coastal areas of southern China. The skin secretions of frogs contain a large amount of biologically active peptides, which have great research value. The peptide QUB-1529 was isolated from the skin secretions of this frog. This peptide belongs to the temporin antimicrobial peptide family, which is one of the largest antimicrobial peptide families possessing broad-spectrum antibacterial effects.

In this study, a molecular cloning strategy was used to clone the peptide encoding cDNA from the frog skin secretion cDNA library, and then the pure peptide was obtained by using RP-HPLC and MALDI-TOF MS techniques. The minimum inhibitory concentration (MIC) assay and MTT assay were carried out to confirm the biological activity of this peptide. From the results, it was shown that QUB-1529 exhibits an excellent antibacterial activity against the Gram-positive bacterium, S. aureus, and the yeast, C. albicans.

With the rapid rise in antibiotic drug resistance, traditional antibiotics have become increasingly irrelevant in clinical practice despite increasing demand. The discovery of novel antimicrobial peptides may be a solution to this problem. Due to the rapid effects of the antimicrobial peptide on the surface of the bacterial membrane, it is difficult to produce drug resistance. Therefore, this class of peptide shows great potential to replace conventional antibiotics. This study unequivocally demonstrated that QUB-1529 exhibits an inhibitory effect on the growth of Gram-positive bacteria and shows the medical development potential of these peptides in replacing antibiotics to treat Gram-positive bacterial infections.

Date of Award	Dec 2020
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Lei Wang (Supervisor), Mei Zhou (Supervisor) & Tianbao Chen (Supervisor)