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oai:figshare.com:article/32640030 2026-10-01T16:34:51Z portal_1172 item_type_8 month_year_10_2026

The development and application of a nematode biofluid peptidomics pipeline for novel bioactive discovery Darrin Mckenzie (12984359) PUREID: 611814781 Nematode parasites peptidomics mass spectrometry neuropeptides antimicrobial peptides (AMPs) drug discovery Parasitic nematodes negatively impact human, animal, and plant health worldwide. Escalating anthelmintic resistance and limited anthelmintics in development highlights an urgent need for the identification of novel drug targets for nematode parasites. Nematode biofluids including: (i) the internal body-cavity fluid [also known as the pseudocoelomic fluid (PCF)], and (ii) excretory-secretory products (ESPs) which are the external biofluids that nematodes release to facilitate interaction with other parasites, pathogens and/or the host, represent potential sources of bioactive peptides which may inform nematode biology and novel drug target discovery. Current research into nematode bioactive peptide profiles have relied heavily on in silico approaches. However, these approaches are predictive in nature and do not provide evidence to confirm bioactive peptide production and/or expression within nematodes. Peptidomics approaches harness liquid-chromatography tandem mass spectrometry (LC-MS/MS) to aid confirmation of bioactive peptide processing and expression and facilitate the detection of novel nematode bioactive peptides. Peptidomics pipelines have been established to investigate peptide profiles in nematode whole-worm lysates. However, limited studies have been conducted on nematode biofluids. This thesis employed multi-disciplinary tools including bioinformatics, LC-MS/MS, high-performance liquid chromatography (HPLC) and automated nematode motility tracking to develop and optimise a nematode biofluid peptidomics pipeline to facilitate detection of peptides in nematode PCF and ESP.<br><br>This thesis highlights the optimisation of a nematode biofluid peptidomics pipeline that enhanced the detection of high-confidence peptides in Ascaris suum PCF (As-PCF). In addition, the optimised nematode biofluid peptidomics pipeline facilitated the detection of full-length neuropeptides in As-PCF for the first time via LC-MS/MS. Translation of the nematode biofluid peptidomics pipeline to nematode ESPs enabled the detection of host facing peptides including 29 putative antimicrobial peptides and one neuropeptide (NLP-77) in three nematode species (A. suum, Haemonchus contortus and Trichuris muris) and provides a blueprint for the detection of peptide profiles in ESPs from other important nematode pathogens. Finally, integration of bioassay-guided and synthetic peptide-guided HPLC fractionation approaches into the nematode biofluid peptidomics pipeline aided in isolation and detection of putative bioactive peptides within As-PCF. The data presented in this thesis represent a significant advance in nematode biofluid peptidomics and has highlighted numerous candidates for functional analyses which may further inform nematode alternative neurosignalling, host-parasite-microbe interactions, chemotherapeutic drug target identification and novel antibiotic development.<br> 2026-10-01T16:34:51Z Text Thesis 10.17034/32640030.v1 https://figshare.com/articles/thesis/The_development_and_application_of_a_nematode_biofluid_peptidomics_pipeline_for_novel_bioactive_discovery/32640030 All Rights Reserved