{"id":{"repo_id":"qu-belfast","oai_identifier":"oai:pure.qub.ac.uk/portal:studenttheses/5ac389f1-abe7-4918-8fcc-27846202f375"},"canonical_url":"https://search.dev.ndltd.org/etd/qu-belfast/oai:pure.qub.ac.uk/portal:studenttheses/5ac389f1-abe7-4918-8fcc-27846202f375","repository":{"repo_id":"qu-belfast","name":"Queen's University Belfast","base_url":"https://pureadmin.qub.ac.uk/ws/oai"},"display":{"title":"QUB-1383, a novel bioactive peptide from the defensive skin secretion of the edible frog (Pelophylax kl. esculentus)","abstract":"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.","abstract_html":"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. &lt;br/&gt;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.","abstract_has_math":false,"creators":["Sang, Mengru"],"institution":"Queen's University Belfast","degree_name":"Master of Philosophy","degree_level":"Masters Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Chen, Tianbao","Wang, Lei","Ma, Chengbang"],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-7","date_published":"2017-7","updated_at":"2026-07-24T03:54:46Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:pure.qub.ac.uk/portal:studenttheses/5ac389f1-abe7-4918-8fcc-27846202f375"],"render_values":[{"text":"oai:pure.qub.ac.uk/portal:studenttheses/5ac389f1-abe7-4918-8fcc-27846202f375","href":null,"code":true}]}]},"links":{"outbound_url":"https://pure.qub.ac.uk/en/studentTheses/5ac389f1-abe7-4918-8fcc-27846202f375","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Chen, Tianbao","Wang, Lei","Ma, Chengbang"]},{"key":"dc:creator","label":"Author","values":["Sang, Mengru"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-7"]},{"key":"dc:date.issued","label":"Date","values":["2017-7"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["School of Pharmacy"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["Queen's University Belfast"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://pure.qub.ac.uk/en/studentTheses/5ac389f1-abe7-4918-8fcc-27846202f375"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters Thesis"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Master of Philosophy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights.embargodate","label":"Dc Rights Embargodate","values":["2019-07-31"]},{"key":"dc:rights.embargoreason","label":"Dc Rights Embargoreason","values":["/dk/atira/pure/core/document/studentthesisembargoreason/publicationissues"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:pure.qub.ac.uk/portal:studenttheses/5ac389f1-abe7-4918-8fcc-27846202f375","https://pure.qub.ac.uk/en/studentTheses/5ac389f1-abe7-4918-8fcc-27846202f375"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://pure.qub.ac.uk/files/137926844/Thesis_corrected_Mengru_Sang_20171116.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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."]},{"key":"dc:title","label":"Title","values":["QUB-1383, a novel bioactive peptide from the defensive skin secretion of the edible frog (Pelophylax kl. esculentus)"]}]}],"canonical_facts":{"dc:contributor.advisor":["Chen, Tianbao","Wang, Lei","Ma, Chengbang"],"dc:creator":["Sang, Mengru"],"dc:date":["2017-7"],"dc:date.issued":["2017-7"],"dc:description.abstract":["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. 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