{"id":{"repo_id":"qu-belfast","oai_identifier":"oai:pure.qub.ac.uk/portal:studenttheses/ae4fe601-e26a-4086-8e64-f7345ac2beb3"},"canonical_url":"https://search.dev.ndltd.org/etd/qu-belfast/oai:pure.qub.ac.uk/portal:studenttheses/ae4fe601-e26a-4086-8e64-f7345ac2beb3","repository":{"repo_id":"qu-belfast","name":"Queen's University Belfast","base_url":"https://pureadmin.qub.ac.uk/ws/oai"},"display":{"title":"Discovery and functional evaluation of a host defense peptide from Rana amurensis","abstract":"Due to the drug-resistant bacterial infections have become a global medical problem, antimicrobial peptides (AMPs) are considered as a new possibility to replace traditional antibiotics. Host-defense peptides in amphibians skins with various biological activities are a rich source for discovering new AMPs. This thesis amid to discover and functionally study a new AMP from the skin secretions of Rana amurensis. A cDNA encoding a new ranatuerin precursor was successfully established through molecular cloning and Sanger sequencing, and the mature peptide sequence of the active form, QUB-2566 (GVLKGVGKNVSGSLLHQLKCLISGGC), was deduced from the cloned cDNA. Thereafter, the corresponding synthetic peptide was obtained by solid-phase Fmoc synthesis, and its antibacterial activity, antiproliferative activity and haemolytic activity were tested. QUB-2566 was found to inhibit the growth of S. aureus and E. coli from a peptide concentration of 1µM; however, it required higher peptide concentration to completely inhibit the growth of these bacteria. Interesting, this peptide exhibited better bactericidal effect against E.coli (MBC=32 μM) than grampositive bacterium (S.aureus) (MBC=128 μM). Moreover, this peptide had less potency against C.albicans (MIC=512μM), along with low haemolytic activity (HC50< 512 μM). Also, peptide QUB-2566 had a weak antiproliferative effect on lung cancer cells H838. Altogether, this peptide may become a lead compound for new antimicrobial drug development because of its potent antibacterial potency against E.coli and low haemolytic activity.","abstract_html":"Due to the drug-resistant bacterial infections have become a global medical problem, antimicrobial peptides (AMPs) are considered as a new possibility to replace traditional antibiotics. Host-defense peptides in amphibians skins with various biological activities are a rich source for discovering new AMPs. This thesis amid to discover and functionally study a new AMP from the skin secretions of Rana amurensis. A cDNA encoding a new ranatuerin precursor was successfully established through molecular cloning and Sanger sequencing, and the mature peptide sequence of the active form, QUB-2566 (GVLKGVGKNVSGSLLHQLKCLISGGC), was deduced from the cloned cDNA. Thereafter, the corresponding synthetic peptide was obtained by solid-phase Fmoc synthesis, and its antibacterial activity, antiproliferative activity and haemolytic activity were tested. QUB-2566 was found to inhibit the growth of S. aureus and E. coli from a peptide concentration of 1µM; however, it required higher peptide concentration to completely inhibit the growth of these bacteria. Interesting, this peptide exhibited better bactericidal effect against E.coli (MBC=32 μM) than grampositive bacterium (S.aureus) (MBC=128 μM). Moreover, this peptide had less potency against C.albicans (MIC=512μM), along with low haemolytic activity (HC50< 512 μM). Also, peptide QUB-2566 had a weak antiproliferative effect on lung cancer cells H838. Altogether, this peptide may become a lead compound for new antimicrobial drug development because of its potent antibacterial potency against E.coli and low haemolytic activity.","abstract_has_math":false,"creators":["Jiang, Shan"],"institution":"Queen's University Belfast","degree_name":"Master of Philosophy","degree_level":"Masters Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Wang, Lei","Zhou, Mei"],"committee_chairs":[],"committee_members":[],"year":2020,"date_issued":"2020-12","date_published":"2020-12","updated_at":"2026-07-24T03:55:31Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:pure.qub.ac.uk/portal:studenttheses/ae4fe601-e26a-4086-8e64-f7345ac2beb3"],"render_values":[{"text":"oai:pure.qub.ac.uk/portal:studenttheses/ae4fe601-e26a-4086-8e64-f7345ac2beb3","href":null,"code":true}]}]},"links":{"outbound_url":"https://pure.qub.ac.uk/en/studentTheses/ae4fe601-e26a-4086-8e64-f7345ac2beb3","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Wang, Lei","Zhou, Mei"]},{"key":"dc:creator","label":"Author","values":["Jiang, Shan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2020-12"]},{"key":"dc:date.issued","label":"Date","values":["2020-12"]},{"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/ae4fe601-e26a-4086-8e64-f7345ac2beb3"]},{"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":["2025-12-31"]},{"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/ae4fe601-e26a-4086-8e64-f7345ac2beb3","https://pure.qub.ac.uk/en/studentTheses/ae4fe601-e26a-4086-8e64-f7345ac2beb3"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://pure.qub.ac.uk/files/220058742/Shan_JiangThesis_2019_2020.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Due to the drug-resistant bacterial infections have become a global medical problem, antimicrobial peptides (AMPs) are considered as a new possibility to replace traditional antibiotics. Host-defense peptides in amphibians skins with various biological activities are a rich source for discovering new AMPs. This thesis amid to discover and functionally study a new AMP from the skin secretions of Rana amurensis. A cDNA encoding a new ranatuerin precursor was successfully established through molecular cloning and Sanger sequencing, and the mature peptide sequence of the active form, QUB-2566 (GVLKGVGKNVSGSLLHQLKCLISGGC), was deduced from the cloned cDNA. Thereafter, the corresponding synthetic peptide was obtained by solid-phase Fmoc synthesis, and its antibacterial activity, antiproliferative activity and haemolytic activity were tested. QUB-2566 was found to inhibit the growth of S. aureus and E. coli from a peptide concentration of 1µM; however, it required higher peptide concentration to completely inhibit the growth of these bacteria. Interesting, this peptide exhibited better bactericidal effect against E.coli (MBC=32 μM) than grampositive bacterium (S.aureus) (MBC=128 μM). Moreover, this peptide had less potency against C.albicans (MIC=512μM), along with low haemolytic activity (HC50< 512 μM). Also, peptide QUB-2566 had a weak antiproliferative effect on lung cancer cells H838. Altogether, this peptide may become a lead compound for new antimicrobial drug development because of its potent antibacterial potency against E.coli and low haemolytic activity."]},{"key":"dc:title","label":"Title","values":["Discovery and functional evaluation of a host defense peptide from Rana amurensis"]}]}],"canonical_facts":{"dc:contributor.advisor":["Wang, Lei","Zhou, Mei"],"dc:creator":["Jiang, Shan"],"dc:date":["2020-12"],"dc:date.issued":["2020-12"],"dc:description.abstract":["Due to the drug-resistant bacterial infections have become a global medical problem, antimicrobial peptides (AMPs) are considered as a new possibility to replace traditional antibiotics. Host-defense peptides in amphibians skins with various biological activities are a rich source for discovering new AMPs. This thesis amid to discover and functionally study a new AMP from the skin secretions of Rana amurensis. A cDNA encoding a new ranatuerin precursor was successfully established through molecular cloning and Sanger sequencing, and the mature peptide sequence of the active form, QUB-2566 (GVLKGVGKNVSGSLLHQLKCLISGGC), was deduced from the cloned cDNA. Thereafter, the corresponding synthetic peptide was obtained by solid-phase Fmoc synthesis, and its antibacterial activity, antiproliferative activity and haemolytic activity were tested. QUB-2566 was found to inhibit the growth of S. aureus and E. coli from a peptide concentration of 1µM; however, it required higher peptide concentration to completely inhibit the growth of these bacteria. Interesting, this peptide exhibited better bactericidal effect against E.coli (MBC=32 μM) than grampositive bacterium (S.aureus) (MBC=128 μM). Moreover, this peptide had less potency against C.albicans (MIC=512μM), along with low haemolytic activity (HC50< 512 μM). Also, peptide QUB-2566 had a weak antiproliferative effect on lung cancer cells H838. 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