Identification and functional study of a novel antimicrobial peptide, QUB-2021, from the skin secretion of Odorrana tiannanensis

Abstract

When a patient is given an antibiotic, there always be a drug resistance. Moreover, due to the overuse of antibiotics, there has been a rapid increase of antibiotic resistance. Antimicrobial peptides (AMP) found in amphibian skin are considered as a novel antibiotic source. In this study, an AMP (QUB-2021) was identified in the skin secretion of Odorrana tiannanensis via “shotgun cloning”. Then, the solid phase peptide synthesis (SPPS) and the reverse phase HPLC were used to produce and purify the peptides for the bioactivity assays. Minimum inhibitory concentration (MIC) assays, minimum bactericidal concentration (MBC) assays and an MTT assay, were utilised to evaluate its antibacterial and anticancer cell activities. The results showed that QUB-2021 had a antibacterial activity with the MIC values of 8 and 16 μM and MBC values of 16and 32 μM (S. aureus ATCC CRM 6538 and E. coli ATCC CRM 8739). However, it did not exhibit an effective activity against yeast (C. albicans ATCC10231). As for antiproliferative activity, it had a considerable anticancer cell effect at 100 μM with the IC50 value of 62.43 μM. Also, it showed weak haemolysis activity on horse red blood cells with a larger than 256 μM HC50 value. QUB-2021 thus has potential to become a novel bactericidal or anticancer agent.

Thesis embargoed until 31st December 2027

Date of Award	Dec 2022
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Lei Wang (Supervisor), Tianbao Chen (Supervisor) & Tao Wang (Supervisor)