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Sibanda, Lloyd

University of British Columbia

For this work, two areas of metabolomics were investigated relating to the fundamentals of the field and application to different experiments. The first chapter was an assessment and comparison of the MSMS spectra generated from different acquisition modes. The chosen acquisition modes were data-dependant acquisition (DDA), data-independent acquisition (DIA), and enhanced insource-fragmentation (eISF) at a range of collision energies. The data was obtained by performing untargeted metabolomics on a urine sample and a standard mixture solution through a LC-MS platform while also covering multiple ionization modes. The spectra from the three modes were compared against each other through several factors that relate to the various ways MSMS spectra are used in a metabolomics workflow. These comparisons involved investigating the spectral purity, quality of reference matching results, structural similarity, and de novo annotation performance. It was found that DDA performed the best with eISF and DIA following. It was seen that eISF performed on-par or slightly better than DIA at higher collision energies. This indicates that the collision energy used will have a notable impact on the performance of the mode. The second chapter involves the metabolomics of pancreatic cell samples. The purpose of this was to determine the metabolic profile between the control and treated groups. The control was regular cancer cells from the MiaPaCa2 cell line while the treated groups had specific genes knocked out. The investigation was performed to gain insight into which metabolic pathways the knocked-out genes were involved in. Using a LC-MS platform it was found that 12 metabolites showed significant intensity differences between the groups. A literature review of these compounds highlighted possible metabolomic pathways affected such as polyamine metabolism. The last chapter focuses on a lipidomics experiment that was performed on the bacteria Thermotoga maritima to investigate the lipid content of the bacterial membranes. The samples relating to each fraction were run through the same LC-MS platform as above. It was seen that there were three significantly different lipids apart from the fatty acid, phosphatidylethanolamine, and phosphatidylinositol lipid classes. These classes have all been shown to be involved in membrane stability and transport.

Text

2022-10-20

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/82945

Chemistry

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/