{"id":{"repo_id":"qu-belfast","oai_identifier":"oai:pure.qub.ac.uk/portal:studenttheses/37f119b0-440b-420a-ae34-aaf8b8adc03c"},"canonical_url":"https://search.dev.ndltd.org/etd/qu-belfast/oai:pure.qub.ac.uk/portal:studenttheses/37f119b0-440b-420a-ae34-aaf8b8adc03c","repository":{"repo_id":"qu-belfast","name":"Queen's University Belfast","base_url":"https://pureadmin.qub.ac.uk/ws/oai"},"display":{"title":"A bioactive peptide, QUB-2048, from the defensive skin secretion of Phyllomedusa tomopterna","abstract":"Amphibian skin is a biochemically, morphologically and physiologically complex organ which is responsible for the survival and defence of amphibians. Amphibian skin secretion is deemed as a reservoir of bioactive compounds and antimicrobial peptides (AMPs) are among the most attractive of these. Due to antibiotic resistance and the eager need of developing new types of anti-infective drugs, such peptides are considered as an alternative therapeutic option due to their potent broad-spectrum antimicrobial activity. Thus, AMPs are arousing great attention in pharmaceutical and biotechnical fields.<br/>In this study, a ‘shotgun’ cloning procedure was employed to construct a skin secretion-derived cDNA library. A peptide precursor-encoding cDNA was successfully cloned from such a library of the tiger-legged monkey tree frog, Phyllomedusa tomopterna, and named QUB-2048. Subsequently, the predicted mature peptide, named QUB-2048 was isolated and identified by reverse-phase HPLC and MALDI-TOF mass spectrometry, and then chemically-synthesised by solid-phase peptide chemistry to facilitate assessment of bioactivity.<br/>QUB-2048 was found to have potent antimicrobial activity against the yeast, Candida albicans and the Gram-positive bacterium, Staphylococcus aureus, against both of which the peptide displayed a minimum inhibitory concentration (MIC) of 4 µM, while displaying a comparatively less potent effect on the Gram-negative bacterium, Escherichia coli with an MIC of 32 µM. QUB-2048 also showed 20% lower haemolytic activity at a concentration of 32 µM compared to Triton X-100. However, it exhibited no effect on the selected human cancer cell lines, U251MG, MB435, H157, and PC3. <br/>","abstract_html":"Amphibian skin is a biochemically, morphologically and physiologically complex organ which is responsible for the survival and defence of amphibians. Amphibian skin secretion is deemed as a reservoir of bioactive compounds and antimicrobial peptides (AMPs) are among the most attractive of these. Due to antibiotic resistance and the eager need of developing new types of anti-infective drugs, such peptides are considered as an alternative therapeutic option due to their potent broad-spectrum antimicrobial activity. Thus, AMPs are arousing great attention in pharmaceutical and biotechnical fields.&lt;br/&gt;In this study, a ‘shotgun’ cloning procedure was employed to construct a skin secretion-derived cDNA library. A peptide precursor-encoding cDNA was successfully cloned from such a library of the tiger-legged monkey tree frog, Phyllomedusa tomopterna, and named QUB-2048. Subsequently, the predicted mature peptide, named QUB-2048 was isolated and identified by reverse-phase HPLC and MALDI-TOF mass spectrometry, and then chemically-synthesised by solid-phase peptide chemistry to facilitate assessment of bioactivity.&lt;br/&gt;QUB-2048 was found to have potent antimicrobial activity against the yeast, Candida albicans and the Gram-positive bacterium, Staphylococcus aureus, against both of which the peptide displayed a minimum inhibitory concentration (MIC) of 4 µM, while displaying a comparatively less potent effect on the Gram-negative bacterium, Escherichia coli with an MIC of 32 µM. QUB-2048 also showed 20% lower haemolytic activity at a concentration of 32 µM compared to Triton X-100. However, it exhibited no effect on the selected human cancer cell lines, U251MG, MB435, H157, and PC3. &lt;br/&gt;","abstract_has_math":false,"creators":["Dong, Bowen"],"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","Zhou, Mei"],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-8-17","date_published":"2017-8-17","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/37f119b0-440b-420a-ae34-aaf8b8adc03c"],"render_values":[{"text":"oai:pure.qub.ac.uk/portal:studenttheses/37f119b0-440b-420a-ae34-aaf8b8adc03c","href":null,"code":true}]}]},"links":{"outbound_url":"https://pure.qub.ac.uk/en/studentTheses/37f119b0-440b-420a-ae34-aaf8b8adc03c","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","Zhou, Mei"]},{"key":"dc:creator","label":"Author","values":["Dong, Bowen"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-8-17"]},{"key":"dc:date.issued","label":"Date","values":["2017-8-17"]},{"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/37f119b0-440b-420a-ae34-aaf8b8adc03c"]},{"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":["2022-09-01"]},{"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/37f119b0-440b-420a-ae34-aaf8b8adc03c","https://pure.qub.ac.uk/en/studentTheses/37f119b0-440b-420a-ae34-aaf8b8adc03c"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://pure.qub.ac.uk/files/147146614/A_bioactive_peptide_QUB_2048_from_the_defensive_skin_secretion_of_Phyllomedusa_tomopterna.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Amphibian skin is a biochemically, morphologically and physiologically complex organ which is responsible for the survival and defence of amphibians. Amphibian skin secretion is deemed as a reservoir of bioactive compounds and antimicrobial peptides (AMPs) are among the most attractive of these. Due to antibiotic resistance and the eager need of developing new types of anti-infective drugs, such peptides are considered as an alternative therapeutic option due to their potent broad-spectrum antimicrobial activity. Thus, AMPs are arousing great attention in pharmaceutical and biotechnical fields.<br/>In this study, a ‘shotgun’ cloning procedure was employed to construct a skin secretion-derived cDNA library. A peptide precursor-encoding cDNA was successfully cloned from such a library of the tiger-legged monkey tree frog, Phyllomedusa tomopterna, and named QUB-2048. Subsequently, the predicted mature peptide, named QUB-2048 was isolated and identified by reverse-phase HPLC and MALDI-TOF mass spectrometry, and then chemically-synthesised by solid-phase peptide chemistry to facilitate assessment of bioactivity.<br/>QUB-2048 was found to have potent antimicrobial activity against the yeast, Candida albicans and the Gram-positive bacterium, Staphylococcus aureus, against both of which the peptide displayed a minimum inhibitory concentration (MIC) of 4 µM, while displaying a comparatively less potent effect on the Gram-negative bacterium, Escherichia coli with an MIC of 32 µM. QUB-2048 also showed 20% lower haemolytic activity at a concentration of 32 µM compared to Triton X-100. However, it exhibited no effect on the selected human cancer cell lines, U251MG, MB435, H157, and PC3. <br/>"]},{"key":"dc:title","label":"Title","values":["A bioactive peptide, QUB-2048, from the defensive skin secretion of Phyllomedusa tomopterna"]}]}],"canonical_facts":{"dc:contributor.advisor":["Chen, Tianbao","Wang, Lei","Zhou, Mei"],"dc:creator":["Dong, Bowen"],"dc:date":["2017-8-17"],"dc:date.issued":["2017-8-17"],"dc:description.abstract":["Amphibian skin is a biochemically, morphologically and physiologically complex organ which is responsible for the survival and defence of amphibians. Amphibian skin secretion is deemed as a reservoir of bioactive compounds and antimicrobial peptides (AMPs) are among the most attractive of these. Due to antibiotic resistance and the eager need of developing new types of anti-infective drugs, such peptides are considered as an alternative therapeutic option due to their potent broad-spectrum antimicrobial activity. Thus, AMPs are arousing great attention in pharmaceutical and biotechnical fields.<br/>In this study, a ‘shotgun’ cloning procedure was employed to construct a skin secretion-derived cDNA library. A peptide precursor-encoding cDNA was successfully cloned from such a library of the tiger-legged monkey tree frog, Phyllomedusa tomopterna, and named QUB-2048. Subsequently, the predicted mature peptide, named QUB-2048 was isolated and identified by reverse-phase HPLC and MALDI-TOF mass spectrometry, and then chemically-synthesised by solid-phase peptide chemistry to facilitate assessment of bioactivity.<br/>QUB-2048 was found to have potent antimicrobial activity against the yeast, Candida albicans and the Gram-positive bacterium, Staphylococcus aureus, against both of which the peptide displayed a minimum inhibitory concentration (MIC) of 4 µM, while displaying a comparatively less potent effect on the Gram-negative bacterium, Escherichia coli with an MIC of 32 µM. QUB-2048 also showed 20% lower haemolytic activity at a concentration of 32 µM compared to Triton X-100. However, it exhibited no effect on the selected human cancer cell lines, U251MG, MB435, H157, and PC3. <br/>"],"dc:identifier":["oai:pure.qub.ac.uk/portal:studenttheses/37f119b0-440b-420a-ae34-aaf8b8adc03c","https://pure.qub.ac.uk/en/studentTheses/37f119b0-440b-420a-ae34-aaf8b8adc03c"],"dc:identifier.uri":["https://pure.qub.ac.uk/files/147146614/A_bioactive_peptide_QUB_2048_from_the_defensive_skin_secretion_of_Phyllomedusa_tomopterna.pdf"],"dc:language":["eng"],"dc:publisher.department":["School of Pharmacy"],"dc:publisher.institution":["Queen's University Belfast"],"dc:relation.isreferencedby":["https://pure.qub.ac.uk/en/studentTheses/37f119b0-440b-420a-ae34-aaf8b8adc03c"],"dc:rights.embargodate":["2022-09-01"],"dc:rights.embargoreason":["/dk/atira/pure/core/document/studentthesisembargoreason/publicationissues"],"dc:title":["A bioactive peptide, QUB-2048, from the defensive skin secretion of Phyllomedusa tomopterna"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Masters Thesis"],"dc:type.qualificationname":["Master of Philosophy"]},"updated_at":"2026-07-24T03:54:46Z"}