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oai:figshare.com:article/32862668 2026-10-01T16:06:28Z portal_1172 item_type_8 month_year_10_2026

QUB-1383, a novel bioactive peptide from the defensive skin secretion of the edible frog (Pelophylax kl. esculentus) Mengru Sang (12357214) PUREID: 137926842 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. 2026-10-01T16:06:28Z Text Thesis 10.17034/32862668.v1 https://figshare.com/articles/thesis/QUB-1383_a_novel_bioactive_peptide_from_the_defensive_skin_secretion_of_the_edible_frog_Pelophylax_kl_esculentus_/32862668 All Rights Reserved