Year of Graduation

2023

Level of Access

Restricted Access Thesis

Embargo Period

5-18-2023

Department or Program

Biochemistry

First Advisor

Danielle Dube

Abstract

The growing dangers of antibiotic-resistant pathogens, and the detrimental effects of nonspecific antibiotics on the endogenous microbiome, necessitate new therapies that can specifically target bacteria. Bacterial glycans, complex monosaccharide structures that adorn the cell surface, represent a compelling therapeutic target, as they differ between species and are involved in bacterial pathogenesis. Unfortunately, their complexity makes them difficult to study. Prior approaches have uncovered some information about bacterial glycans, but they are limited in their ability to elucidate detail about biosynthetic pathways that is critical to the rational design of glycan-based therapeutics. Prior work has demonstrated the potential of fluorescent analogs of common monosaccharides to uncover this information. These analogs have already revealed information about both glycosyl hydrolase (GH) activity and cellular uptake of monosaccharide substrates, two critical stages of the glycan biosynthetic pathway. However, this approach has yet to be attempted with bacterial monosaccharide analogs. In the studies performed herein, a panel of custom-built fluorescent monosaccharide analogs constructed from two different bacterial sugars, FucNAc and DATDH, was used to assay bacterial GH enzymatic activity and monosaccharide uptake in select priority pathogens and other bacterial species. Fluorescent probes based on the common monosaccharide glucose were also used as a control. Preliminary results demonstrate the successful detection of GH activity in mammalian cells but do not successfully indicate GH activity in bacterial cells. On the other hand, fluorescent monosaccharide analogs implied differential uptake mechanisms in various bacterial species, potentiating the future use of these probes to study monosaccharide processing mechanisms in bacteria.

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