Nanomolar affinity, iminosugar-based chemical probes for specific labeling of lysosomal glucocerebrosidase

Three different photoprobes were synthesized to label beta-glucosidases; one probe was based on glucose, two probes on the iminosugar deoxynojirimycin. The affinity of the probes for three different beta-glucosidases was determined. Furthermore, their labeling efficiencies, binding specificities through competition with deoxynojirimycin, and binding specificities in the presence of cell lysate, were evaluated. Especially one showed very high affinity towards non-lysosomal glucoceramidase (IC(50)=20 nM).