Prism[5]arene Iminosugar Bioconjugates Are Potent Multivalent Inhibitors and Mutation Specific Pharmacological Chaperones of Glucocerebrosidase (GCase) Activity

Abstract

When trihydroxypiperidine (PIP) or DAB-1 pyrrolidine (PYR) iminosugars are multimerized on the prism[5]arene scaffold, they generate highly efficient multivalent inhibitors of GCase. Binding trihydroxypiperidine to the rims of prism[5]arene (PrS[5]PIP) results in a multivalent derivative that is more effective than others reported in the literature with the same bioactive unit. This efficacy is attributed to the role of prism[5]arene, whose barrel-like shape exposes an external π-surface that enables van der Waals contacts and other secondary interactions with the enzyme, thereby enhancing affinity for GCase through dimer stabilization. The high efficiency of PrS[5]PIP is supported by in silico calculations that showed how the crowding of the bioactive units on the rims of the macrocycle promotes a rearrangement allowing the active site to accommodate two trihydroxypiperidine units, which engage in hydrogen bonding with the catalytically active Glu residues. Due to their inhibitory potency, these prismarene derivatives have been tested as pharmacological chaperones in intact cell lines from Gaucher patients carrying different mutations. The results indicated that the PrS[5]PIP is more effective toward the N370S mutation, while the DAB-1 pyrrolidine iminosugar PrS[5]PYR unexpectedly enhances L444P mutant GCase activity. This suggests that the type of iminosugar linked to the prismarene scaffold influences GCase activity rescue in a mutation-dependent manner and opens the way for the future development of increasingly efficient pharmacological chaperones.