Département de chimie moléculaire

Nature's catalysts are specifically evolved to carry out efficient and selective reactions. Recent developments in biotechnol. have allowed the rapid optimization of existing enzymes for enantioselective processes. However, the ex nihilo creation of catalytic activity from a noncatalytic protein scaffold remains very challenging. Herein, we describe the creation of an artificial enzyme upon incorporation of a vanadyl ion into the biotin-binding pocket of streptavidin, a protein devoid of catalytic activity. The resulting artificial metalloenzyme catalyzes the enantioselective oxidn. of prochiral sulfides with good enantioselectivities both for dialkyl and alkyl-aryl substrates (up to 93{%} enantiomeric excess). ESR spectroscopy, chem. modification, and mutagenesis studies suggest that the vanadyl ion is located within the biotin-binding pocket and interacts only via second coordination sphere contacts with streptavidin. [on SciFinder(R)]