Selective Hydrolysis of Aryl Esters under Acidic and Neutral Conditions by a Synthetic Aspartic Protease Mimic

Abstract

Aspartic proteases use a pair of carboxylic acids to activate water molecules for nucleophilic attack. Here we report a nanoparticle catalyst with a similar catalytic motif capable of generating a hydroxide ion in its active site even under acidic reaction conditions. The synthetic enzyme accelerated the hydrolysis of para-nitrophenyl acetate (PNPA) by 91 000 times and could also hydrolyze nonactivated aryl esters at pH 7. The distance between the two acids and, in particular, the flexibility of the catalytic groups in the active site controlled the catalytic efficiency. The synthetic enzyme readily detected the addition of a single methyl on the acyl group of the substrate, as well as the substitution pattern on the phenyl ring.

Mimicking Enzymes: The Quest for Powerful Catalysts from Simple Molecules to Nanozymes

“…AuNPs constitute a valuable option to elicit cooperativity in a synthetic catalyst. Other nanoplatforms, but gold clusters are used for preparing nanocatalysts as resins, polymers, polymeric nanoparticles, inorganic nanoparticles passivated with imprinted polymers, carbon dots, graphene oxide, and metal–organic frameworks, just to mention a few. In contrast to simple, unimolecular catalysts, these systems may allow one to take advantage of all four features, common to natural enzymes, that we have illustrated in the Introduction.…”

Molecularly imprinted polymer nanoparticles for the recognition of ellagic acid

“…Such nanoMIPs can mainly be used in catalytic applications. 34,35 Precipitation polymerization can also generate nanoMIPs. This approach, which was applied first time by Ye to produce nanoMIPs, comprises polymerization with soluble reactants in a high-dilution media, followed by the formation of insoluble nanoMIPs.…”

“…Zhao and coworkers developed a micellar imprinting technique to create nanoMIPs with a hydrophobic core hydrophilic shell that can work in aqueous solutions. Such nanoMIPs can mainly be used in catalytic applications 34,35 . Precipitation polymerization can also generate nanoMIPs.…”

Dynamic Tuning in Synthetic Glycosidase for Selective Hydrolysis of Alkyl and Aryl Glycosides

“…A nanoconfined environment in micellar imprinting affords an extraordinary imprinting effect, and the resulting molecularly imprinted nanoparticles (MINPs) often display imprinting factors in the hundreds or even 10,000 . Specific functional groups may be introduced in the imprinted pockets to turn MINPs into artificial enzymes. − …”

“…Micellar imprinting, therefore, is extremely faithful in reproducing structural features of the template in the imprinted site. 22). Thus, the hydrophobic pyrenyl group contributes majorly to the binding of the templates.…”