Discovery and bioactivity assessment of a novel peptide from the skin secretion of the Senegal running frog Kassina senegalens

Frog skin is characterised with an abundance of biologically active antimicrobial peptides (AMPs) with a broad-spectrum effect against a variety of microorganisms. The contribution of their complex and diverse structures, physicochemical properties and mechanisms of biological activity, have been discovered and widely reported. In this study, a novel peptide named QUB-1923 was identified from the skin secretion of the Senegal running frog, Kassina senegalensis. The sequence of the mature peptide (FYHLSALIHGIKQRLK) was deduced from the cloned cDNA encoding a prepropeptide. Subsequently, this peptide was chemically synthesised by solid-phase synthesis. Following on from the purification by RP-HPLC and MALDI-TOF MS, the antimicrobial, anti-cancer cell proliferative and haemolytic activities of the purified peptide QUB-1923 were investigated. Results from antimicrobial assays have shown that this peptide has a broad-spectrum antimicrobial effect on S. aureus, E. coli and C. albicans. Notably, this peptide displayed the highest antimicrobial activity against E. coli (MIC=4 μM, and MBC=8 μM). On the other hand, this peptide only caused approximately 20% growth inhibition on lung cancer cell line H838 at a concentration of 100 μM. Additionally, this peptide demonstrated less than 10% haemolysis at a concentration of 256µM. These results suggest that this novel peptide is worthy of attention as a new antibacterial lead due to its potent inhibitory and bactericidal effects against Gram-ve bacteria, along with a low level of haemolysis.<br/><i><br/>Thesis embargoed until 31 December 2026</i>.

Name dc:type.qualificationname

Master of Philosophy

Level dc:type.qualificationlevel

Masters Thesis

Grantor dc:publisher.institution

Queen's University Belfast

Year dc:date.issued

2021

Author dc:creator

• Zhou, Chunyuan

Advisors dc:contributor.advisor

• Zhou, Mei
• Wang, Lei
• Chen, Tianbao
• Chen, Xiaoling

• Antimicrobial peptide
• bioactivity assessment
• broad-spectrum antimicrobial activity
• low haemolysis activity
• novel peptide

Language dc:language

eng

Identifier

oai:pure.qub.ac.uk/portal:studenttheses/d1ead41c-acc5-419c-8636-529f4aa6942f

OAI identifier oai:identifier

oai:pure.qub.ac.uk/portal:studenttheses/d1ead41c-acc5-419c-8636-529f4aa6942f