Physical Sciences and Mathematics Commons^™

Effects Of Oxidative Modifications On The Structure And Non-Canonical Functions Of Cytochrome C Studied By Mass Spectrometry, Victor Yin

Electronic Thesis and Dissertation Repository

The peroxidase activity of the mitochondrial protein cytochrome c (cyt c) plays a critical role in triggering programmed cell death, or apoptosis. However, the native structure of cyt c should render this activity impossible due to the lack of open iron coordination sites at its heme cofactor. Despite its key biological importance, the molecular mechanisms underlying this structure-function mismatch remain enigmatic. The work detailed in this dissertation fills this knowledge gap by using mass spectrometry (MS) to decipher the central role that protein oxidative modifications and their associated structural changes play in activating the peroxidase function of cyt c …

Analysis Of Secondary Metabolites Biosynthesized By Pathogenic And Symbiotic Fungi Using High-Resolution Tandem Lc-Ms And Spectral Molecular Networking, Natasha Desrochers

Electronic Thesis and Dissertation Repository

Fungi from Canadian crops affect many aspects of agriculture. For example, ginseng root rot caused by Ilyonectria spp. is a major issue for farmers. Ilyonectria spp. make few reported natural products and it is not known if those products are unique to virulent species. PCA and molecular networking were applied to HRMS data to establish a distinct metabolomic profile of root rot pathogens, characterized by antifungal resorcyclic acid lactones (RALs). These likely protect Ilyonectria from other soil pathogens, which gives it the opportunity to infect ginseng root.

Molecular networking was also applied to fungal endophytes from fruit crops to identify …