Carba-cyclophellitols Are Neutral Retaining-Glucosidase Inhibitors

Area of Science:

• Biochemistry
• Enzyme Inhibitor Design
• Computational Chemistry

Background:

• Glycosidases are crucial enzymes involved in various biological processes.
• Developing specific inhibitors for glycosidases is important for therapeutic applications.
• Transition-state mimicry is a successful strategy for designing potent enzyme inhibitors.

Purpose of the Study:

• To design and synthesize a novel carba-cyclophellitol analogue as a retaining β-glucosidase inhibitor.
• To investigate the conformational preferences of cyclopropyl inhibitors using computational methods.
• To evaluate the inhibitory activity of the novel compound against Thermotoga maritima TmGH1 β-glucosidase.

Main Methods:

• Ab initio metadynamics simulations to analyze conformational free energy landscapes.
• Synthesis of carba-cyclophellitol with an N-(4-azidobutyl)carboxamide moiety.
• Enzyme inhibition assays and 3-D structural analysis.

Main Results:

• Simulations revealed a strong bias for the ⁴H₃ transition-state conformation in cyclopropyl inhibitors.
• Carba-cyclophellitol demonstrated potent inhibition of TmGH1 β-glucosidase with a K_i of 8.2 nM.
• Structural analysis confirmed binding in the ⁴H₃ conformation, validating the design strategy.

Conclusions:

• The carba-cyclophellitol analogue is a potent inhibitor of Thermotoga maritima TmGH1 β-glucosidase.
• Conformational strain induced by the cyclopropyl unit enhances inhibitor binding affinity.
• This approach offers a promising strategy for developing novel, tight-binding enzyme inhibitors.