The discovery of a novel peptide, QUB-2274, from the defensive skin secretion of Rana amurensis

Based on extensive natural drug investigations, frog skin has been found to be a rich source of biologically active compounds, especially the broad-spectrum antimicrobial peptides, which have attracted increasing attention as potential therapeutic agents.<br/><br/>In this thesis, a novel bioactive peptide was discovered in the skin secretion of Rana amurensis. This skin secretion was collected by mild electrical stimulation and used to isolate mRNA for the establishment of a cDNA library. “Shotgun” cloning was employed to obtain the peptide precursor-encoding cDNA sequence and the mature peptide structure was deduced from this cloned cDNA. A sufficient quantity of a peptide replicate for bioactivity testing, was synthesised by solid-phase peptide synthesis (SPPS). <br/><br/>After these tests, QUB-2274 was found to exhibit differential growth-inhibitory activity towards the Gram-positive bacterium S.aureus, the Gram-negative bacterium E.coli, and the yeast C.albicans, but with a high haemolytic activity. It also had a strong anti-proliferative effect on the four tested human cancer cell lines: PC-3, NCI-H157, MDA-MB-435S and U251MG.<br/><br/>These studies on QUB-2274, have provided the basic data for research on a bioactive peptide from an amphibian. Unlike conventional antibiotics, the antimicrobial peptides (AMPs) are less likely to cause drug resistance. If QUB-2274 is to be considered for application in the clinic, its high haemolytic activity requires addressing such as by rational analogue design. <br/>

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

2017

Author dc:creator

• Xu, Yiwen

Advisors dc:contributor.advisor

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

Language dc:language

eng

Identifier

oai:pure.qub.ac.uk/portal:studenttheses/7776ef42-e321-4153-b1af-5e78bdb6c681

OAI identifier oai:identifier

oai:pure.qub.ac.uk/portal:studenttheses/7776ef42-e321-4153-b1af-5e78bdb6c681