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oai:figshare.com:article/32640072 2026-10-01T16:34:30Z portal_1172 item_type_8 month_year_10_2026

Molecular cloning and functional investigation of a novel antimicrobial peptide, QUB-1348, from the skin secretion of the spiny frog, Hylarana spinulosa Shuangxiu Wu (644349) PUREID: 612473238 AMPs Haemolytic activity Antiproliferation avtivity SPPS cDNA Antimicrobial peptides (AMPs) are a diverse and potent group of molecules derived from various invertebrate, plant, and animal species. A variety of biological activity, such as antiviral and anticancer properties, make AMPs attractive candidates for the development of novel drugs. The antimicrobial peptide, QUB-1348, which was extracted from the skin secretions of Hylarana spinulosa, is the main topic of this thesis. Based on existing literature and database searches, the sequence and activity of QUB-1348 have not been previously reported, indicating that this peptide is a novel discovery.<br><br>Using a cDNA library generated from skin secretions, this study is the first to find the biosynthetic precursor encoding the cDNA of QUB-1348, even though the mature peptide sequence FISGLISGLMKAL-NH2 has been identified before. RP-HPLC was utilised to purify the crude peptide. Using a Tribute peptide synthesiser, QUB-1348 was synthesised and MALDI-TOF mass spectrometry was used to confirm its molecular mass. <br><br>Tests for haemolysis, antiproliferation, and antibacterial properties were among the several assays used to evaluate the bioactivities of pure QUB-1348. QUB-1348 showed strong antibacterial action in tests against three model microorganisms: the Gram-positive bacterium, Staphylococcus aureus, the Gram-negative bacterium, Escherichia coli, and the yeast, Candida albicans. The relative MICs were 4 µM, 8 µM, and 32 µM. Furthermore, QUB-1348 has obvious hemolytic activity above the concentration of 32 μm. MTT assay showed that QUB-1348 had anti-proliferation effect on H-838 lung cancer cells, and the average IC50 was 21.36 μM. This indicates that QUB-1348 is still toxic to human cells, but it has obvious antibacterial and anti-proliferative activities. It is hoped that future drug research can apply its biological activity, and reduce its toxicity, so that it can be used in the clinic.<br><br><i>Thesis is embargoed until 31 December 2029.</i><br> 2026-10-01T16:34:30Z Text Thesis 10.17034/32640072.v1 https://figshare.com/articles/thesis/Molecular_cloning_and_functional_investigation_of_a_novel_antimicrobial_peptide_QUB-1348_from_the_skin_secretion_of_the_spiny_frog_Hylarana_spinulosa/32640072 All Rights Reserved Open Access after 2029-12-31