Applications for activity-based probes in biomedical research on glycosidases

Lysosomal glycosidases are acid hydrolases that fragment glycoconjugates in lysosomes. Their inherited deficiency in human is the cause of a number of lysosomal storage disorders (LSDs), showing characteristic lysosomal accumulation of undegraded glycoconjugates. In the past, activity-based probes (ABPs) based on cyclophellitol or cyclophellitol aziridine scaffold have emerged as powerful tools enabling sensitive quantification of a number of lysosomal glycosidases in extracts of cells and tissue, as well as in intact cells. This thesis describes the characterization of several novel ABP classes targeting α-glucosidase, β-glucuronidase, α-L-iduronidase, α-mannosidase, β-mannosidase, and β-galactosidase, as well as a broad scale of applications for ABPs in LSD research. Novel glucocerebrosidase inhibitors based on the cyclophellitol scaffold are also described, which are brain-permeable, selective, and potently inactivate the enzyme in adult zebrafish. Additionally, a protocol for gel-based and microscopy-based detection of glucocerebrosidase is described.