We report here the first example of peptide-functionalized gold nanoparticles hydrolytically active against carboxylate esters. The active units are constituted by His-Phe-OH terminating thiols. The confinement of the catalytic units in the monolayer covering the nanoparticles triggers a cooperative hydrolytic mechanism operative at pH <7 in which a carboxylate and an imidazolium ion act as general base and general acid, respectively. Such a mechanism is absent with an analogous monomeric dipeptide, and this results in a more than 300-fold rate acceleration of the hydrolytic process at low pH in the presence of the functional nanoparticles.
Titolo: | Carboxylate-Imidazole Cooperativity in dipeptide-functionalized gold nanoparticles with esterase-like activity |
Autori: | |
Data di pubblicazione: | 2005 |
Stato di pubblicazione: | Pubblicato |
Rivista: | |
Abstract: | We report here the first example of peptide-functionalized gold nanoparticles hydrolytically active against carboxylate esters. The active units are constituted by His-Phe-OH terminating thiols. The confinement of the catalytic units in the monolayer covering the nanoparticles triggers a cooperative hydrolytic mechanism operative at pH <7 in which a carboxylate and an imidazolium ion act as general base and general acid, respectively. Such a mechanism is absent with an analogous monomeric dipeptide, and this results in a more than 300-fold rate acceleration of the hydrolytic process at low pH in the presence of the functional nanoparticles. |
Handle: | http://hdl.handle.net/11368/2626246 |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1021/ja043547c |
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