{"id":{"repo_id":"qu-belfast","oai_identifier":"oai:pure.qub.ac.uk/portal:studenttheses/da09afc0-8aac-4064-8ec6-ec778062cd26"},"canonical_url":"https://search.dev.ndltd.org/etd/qu-belfast/oai:pure.qub.ac.uk/portal:studenttheses/da09afc0-8aac-4064-8ec6-ec778062cd26","repository":{"repo_id":"qu-belfast","name":"Queen's University Belfast","base_url":"https://pureadmin.qub.ac.uk/ws/oai"},"display":{"title":"A bioactive peptide from the skin secretion of the Red-eyed Leaf Frog, Agalychnis callidryas","abstract":"Natural products, as rich and varied resources for the discovery of novel drugs, have been essential for human healthcare systems throughout history. A variety of bioactive components with unique structures and functions isolated from the skin secretion of amphibians, especially peptides, have enormous potential for medical purposes. <br/><br/>Here, a peptide from the phylloseptin family was identified from the Red-eyed Leaf Frog, Agalychnis callidryas, by molecular cloning. This peptide was named as QUB-1541 based on its molecule weight. Then the mature peptide was successfully synthesised by Tribute® 2-channel peptide synthesiser. Reversed-phase high- performance liquid chromatography (RP-HPLC) was used for purification and matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) MS was used to confirm its molecular mass. QUB-1541 has better inhibitory activity against gram-positive bacteria than gram-negative bacteria. The MIC for S. aureus is 8 μM while for E. coli is 512 μM. Also, QUB-1541 inhibits the growth of yeast, C. albicans and the MIC is 128 μM. The results of MBC show that QUB-1541 has no bactericidal effect on E. coli and C. albicans at the highest concentration. However, QUB-1541 kills S. aureus at a lower level of 16 μM, while the haemolysis is weak. QUB-1541 was only effective against cancer cells, PC-3, U251MG and H157 at the highest concentration of 10-4 M. Thus, QUB-1541 has the value of subsequent research.<br/><br/><i>Thesis embargoed until 31st October 2024 </i><br/>","abstract_html":"Natural products, as rich and varied resources for the discovery of novel drugs, have been essential for human healthcare systems throughout history. A variety of bioactive components with unique structures and functions isolated from the skin secretion of amphibians, especially peptides, have enormous potential for medical purposes. &lt;br/&gt;&lt;br/&gt;Here, a peptide from the phylloseptin family was identified from the Red-eyed Leaf Frog, Agalychnis callidryas, by molecular cloning. This peptide was named as QUB-1541 based on its molecule weight. Then the mature peptide was successfully synthesised by Tribute® 2-channel peptide synthesiser. Reversed-phase high- performance liquid chromatography (RP-HPLC) was used for purification and matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) MS was used to confirm its molecular mass. QUB-1541 has better inhibitory activity against gram-positive bacteria than gram-negative bacteria. The MIC for S. aureus is 8 μM while for E. coli is 512 μM. Also, QUB-1541 inhibits the growth of yeast, C. albicans and the MIC is 128 μM. The results of MBC show that QUB-1541 has no bactericidal effect on E. coli and C. albicans at the highest concentration. However, QUB-1541 kills S. aureus at a lower level of 16 μM, while the haemolysis is weak. QUB-1541 was only effective against cancer cells, PC-3, U251MG and H157 at the highest concentration of 10-4 M. Thus, QUB-1541 has the value of subsequent research.&lt;br/&gt;&lt;br/&gt;&lt;i&gt;Thesis embargoed until 31st October 2024 &lt;/i&gt;&lt;br/&gt;","abstract_has_math":false,"creators":["Zhang, Yan"],"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","Zhou, Mei","Wang, Lei","Ma, Chengbang"],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019-12","date_published":"2019-12","updated_at":"2026-07-24T03:55:05Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:pure.qub.ac.uk/portal:studenttheses/da09afc0-8aac-4064-8ec6-ec778062cd26"],"render_values":[{"text":"oai:pure.qub.ac.uk/portal:studenttheses/da09afc0-8aac-4064-8ec6-ec778062cd26","href":null,"code":true}]}]},"links":{"outbound_url":"https://pure.qub.ac.uk/en/studentTheses/da09afc0-8aac-4064-8ec6-ec778062cd26","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Chen, Tianbao","Zhou, Mei","Wang, Lei","Ma, Chengbang"]},{"key":"dc:creator","label":"Author","values":["Zhang, Yan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2019-12"]},{"key":"dc:date.issued","label":"Date","values":["2019-12"]},{"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/da09afc0-8aac-4064-8ec6-ec778062cd26"]},{"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":["2024-10-31"]},{"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/da09afc0-8aac-4064-8ec6-ec778062cd26","https://pure.qub.ac.uk/en/studentTheses/da09afc0-8aac-4064-8ec6-ec778062cd26"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://pure.qub.ac.uk/files/201331293/A_bioactive_peptide_from_the_skin_secretion_of_the_Red_eyed_Leaf_Frog_Agalychnis_callidryas.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Natural products, as rich and varied resources for the discovery of novel drugs, have been essential for human healthcare systems throughout history. A variety of bioactive components with unique structures and functions isolated from the skin secretion of amphibians, especially peptides, have enormous potential for medical purposes. <br/><br/>Here, a peptide from the phylloseptin family was identified from the Red-eyed Leaf Frog, Agalychnis callidryas, by molecular cloning. This peptide was named as QUB-1541 based on its molecule weight. Then the mature peptide was successfully synthesised by Tribute® 2-channel peptide synthesiser. Reversed-phase high- performance liquid chromatography (RP-HPLC) was used for purification and matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) MS was used to confirm its molecular mass. QUB-1541 has better inhibitory activity against gram-positive bacteria than gram-negative bacteria. The MIC for S. aureus is 8 μM while for E. coli is 512 μM. Also, QUB-1541 inhibits the growth of yeast, C. albicans and the MIC is 128 μM. The results of MBC show that QUB-1541 has no bactericidal effect on E. coli and C. albicans at the highest concentration. However, QUB-1541 kills S. aureus at a lower level of 16 μM, while the haemolysis is weak. QUB-1541 was only effective against cancer cells, PC-3, U251MG and H157 at the highest concentration of 10-4 M. Thus, QUB-1541 has the value of subsequent research.<br/><br/><i>Thesis embargoed until 31st October 2024 </i><br/>"]},{"key":"dc:title","label":"Title","values":["A bioactive peptide from the skin secretion of the Red-eyed Leaf Frog, Agalychnis callidryas"]}]}],"canonical_facts":{"dc:contributor.advisor":["Chen, Tianbao","Zhou, Mei","Wang, Lei","Ma, Chengbang"],"dc:creator":["Zhang, Yan"],"dc:date":["2019-12"],"dc:date.issued":["2019-12"],"dc:description.abstract":["Natural products, as rich and varied resources for the discovery of novel drugs, have been essential for human healthcare systems throughout history. A variety of bioactive components with unique structures and functions isolated from the skin secretion of amphibians, especially peptides, have enormous potential for medical purposes. <br/><br/>Here, a peptide from the phylloseptin family was identified from the Red-eyed Leaf Frog, Agalychnis callidryas, by molecular cloning. This peptide was named as QUB-1541 based on its molecule weight. Then the mature peptide was successfully synthesised by Tribute® 2-channel peptide synthesiser. Reversed-phase high- performance liquid chromatography (RP-HPLC) was used for purification and matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) MS was used to confirm its molecular mass. QUB-1541 has better inhibitory activity against gram-positive bacteria than gram-negative bacteria. The MIC for S. aureus is 8 μM while for E. coli is 512 μM. Also, QUB-1541 inhibits the growth of yeast, C. albicans and the MIC is 128 μM. The results of MBC show that QUB-1541 has no bactericidal effect on E. coli and C. albicans at the highest concentration. However, QUB-1541 kills S. aureus at a lower level of 16 μM, while the haemolysis is weak. QUB-1541 was only effective against cancer cells, PC-3, U251MG and H157 at the highest concentration of 10-4 M. 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