QUB-1383, a novel bioactive peptide from the defensive skin secretion of the edible frog (Pelophylax kl. esculentus)

In this study, a novel peptide named QUB-1383 was successfully isolated from the skin secretion of the edible frog (Pelophylax kl. esculentus) via “shotgun” cloning of the precursor-encoding cDNA. Afterwards, the predicted mature peptide was chemically synthesised by solid-phase peptide synthesis and its structure confirmed via MALDI-TOF mass spectrometry. Then the crude synthesised peptide was purified via RP-HPLC. Several bioassays including antimicrobial assays, haemolytic assays and trypsin inhibitor assays were conducted to ascertain its bioactivities. The synthetic QUB-1383 not only possessed potent antimicrobial activity against C.albicans, S. aureus and E. coli with minimal inhibitory concentrations at 4 μM, 2 μM and 16 μM, respectively. However, it also displayed relatively strong haemolytic activity with EC50 value at 39.64 μM. QUB-1383 also exerted weak inhibitory effect to trypsin, with a Ki value of 20.74 ± 6.87 μM. <br/>Due to the potent antimicrobial activity of QUB-1383, this peptide could be considered as a candidate of novel antibiotics after target-modification to minimise its haemolytic effect. Since the working concentration of QUB-1383 to inhibit trypsin was too high, the trypsin inhibitory activity could not be considered for further development.

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

• Sang, Mengru

Advisors dc:contributor.advisor

• Chen, Tianbao
• Wang, Lei
• Ma, Chengbang

Language dc:language

eng

Identifier

oai:pure.qub.ac.uk/portal:studenttheses/5ac389f1-abe7-4918-8fcc-27846202f375

OAI identifier oai:identifier

oai:pure.qub.ac.uk/portal:studenttheses/5ac389f1-abe7-4918-8fcc-27846202f375