2026-10-10T13:29:30Z https://api.figshare.com/v2/oai

oai:figshare.com:article/32640180 2026-10-01T16:33:28Z portal_1172 item_type_8 month_year_10_2026

Characterisation and bioactivity evaluation of a frog-skin derived peptide, QUB-1931, from the skin secretion of the <i>Odorrana grahami</i> Yidong Zhang (4528342) PUREID: 613662604 antimicrobial peptide molecular cloning solid phase peptide synthesis antimicrobial cytotoxicity anticancer Antimicrobial peptides (AMPs) are natural low molecular mass proteins extracted from species of all kingdoms, with a wide range antimicrobial activity against bacteria, viruses, fungi and protozoa. Compared with traditional antimicrobial drugs, AMPs induce less antimicrobial resistance and have stronger antimicrobial effects. Amphibians have been considered as significant sources of AMPs, and various AMPs have been isolated and characterized from their skin secretions. Generally, AMPs are characterized by the conserved amino acid sequences, specific secondary structures, hydrophobicity and net positive charges. The aim of this study was to identify and characterise a novel peptide by cloning from the skin secretion of Odorrana grahami. Then, to evaluate the bioactivity of the identified peptide, including its antimicrobial activity, anti-cancer activity and cytotoxicity. In this research, one new AMP, QUB-1931, was identified. As a member of the nigrocin family, QUB-1931 showed relatively strong inhibitory effects against C. albicans, with a minimum significant effective concentration of 32 µM. Also, QUB-1931 demonstrated low cytotoxicity, with a 10% haemolysis concentration of 391.7 µM on horse erythrocytes. These findings suggest that QUB-1931 is an AMP with low cytotoxicity and potential antimicrobial effect against Gram-negative bacteria. QUB-1931 exerted no significant anticancer activity against a human cancer cell line (NSCLC, H838). Collectively, QUB-1931 showed bioactivity against Gram-negative bacteria and low cytotoxicity, consistent with previous research relevant to the nigrocin family. These findings indicate the potential antimicrobial applications of QUB-1931 for clinical practice, following modification to improve activity.<br><br><i>Thesis is embargoed until 31st December 2029</i>.<br><br> 2026-10-01T16:33:28Z Text Thesis 10.17034/32640180.v1 https://figshare.com/articles/thesis/Characterisation_and_bioactivity_evaluation_of_a_frog-skin_derived_peptide_QUB-1931_from_the_skin_secretion_of_the_i_Odorrana_grahami_i_/32640180 All Rights Reserved Open Access after 2029-12-31