<br/>The active sites of zinc (II) containing hydrolytic enzymes typically have histidines, glutamates or aspartates and in some cases cysteines coordinated. We have synthesized a macrocylcic amine ligand with a pendant cyclodextrin ring, namely, 1,5,9-triazacyclododecane β-cyclodextrin, (TACD β-cyclodextrin) that presents three amine nitrogen donors for Zn (II) coordination and a proximal cyclodextrin ring for substrate binding as well as coordination with an alkaline earth metal ion, Ba (II). This presentation will demonstrate the effectiveness of this complex to catalyze the hydrolysis of an activated ester at the pH corresponding to the pKa of the Zin (II) bound water that upon deprotonation serves as a nucleophile during the hydrolysis. Rate enhancement for the hydrolysis of p-nitrophenyl phosphate (PNPA) with the Zn (II) complex in presence of Ba(II) ion bound to β-cyclodextrin over that of the complex in its absence is presented. The effect of substrate concentration on the catalytic reaction will be examined to determine the catalytic turnover number.

Cooperative catalytic hydrolysis using a dinuclear metalloenzyme mimic

2019 Spring National Meeting

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