Selective labelling of GBA2 in cells with fluorescent beta-d-arabinofuranosyl cyclitol aziridines.
Su, Q., Louwerse, M., Lammers, R.F., Maurits, E., Janssen, M., Boot, R.G., Borlandelli, V., Offen, W.A., Linzel, D., Schroder, S.P., Davies, G.J., Overkleeft, H.S., Artola, M., Aerts, J.M.F.G.(2024) Chem Sci 15: 15212-15220
- PubMed: 39246358 
- DOI: https://doi.org/10.1039/d3sc06146a
- Primary Citation of Related Structures:  
8R1M - PubMed Abstract: 
GBA2, the non-lysosomal β-glucosylceramidase, is an enzyme involved in glucosylceramide metabolism. Pharmacological inhibition of GBA2 by N -alkyl iminosugars is well tolerated and benefits patients suffering from Sandhoff and Niemann-Pick type C diseases, and GBA2 inhibitors have been proposed as candidate-clinical drugs for the treatment of parkinsonism. With the ultimate goal to unravel the role of GBA2 in (patho)physiology, we sought to develop a GBA2-specific activity-based probe (ABP). A library of probes was tested for activity against GBA2 and the two other cellular retaining β-glucosidases, lysosomal GBA1 and cytosolic GBA3. We show that β-d-arabinofuranosyl cyclitol aziridine (β-d-Araf aziridine) reacts with the GBA2 active site nucleophile to form a covalent and irreversible bond. Fluorescent β-d-Araf aziridine probes potently and selectively label GBA2 both in vitro and in cellulo , allowing for visualization of the localization of overexpressed GBA2 using fluorescence microscopy. Co-staining with an antibody selective for the lysosomal β-glucosylceramidase GBA1, shows distinct subcellular localization of the two enzymes. We proffer our ABP technology for further delineating the role and functioning of GBA2 in disease and propose the β-d-Araf aziridine scaffold as a good starting point for the development of GBA2-specific inhibitors for clinical development.
Organizational Affiliation: 
Department of Medical Biochemistry, Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands j.m.f.g.aerts@lic.leidenuniv.nl m.e.artola@lic.leidenuniv.nl.