Options
Hierarchical Self-Assembly of One-Dimensional Streptavidin Bundles as a Collagen Mimetic for the Biomineralization of Calcite
Auteur(s)
Burazerovic, Sabina
Gradinaru, Julieta
Pierron, Julien
Ward, Thomas R.
Date de parution
2007
In
Angewandte Chemie International Edition, Wiley, 2007/46/29/5510-5514
Résumé
We report on our efforts to create efficient artificial metalloenzymes for the enantioselective hydrogenation of <i>N</i>-protected dehydroamino acids using either avidin or streptavidin as host proteins. Introduction of chiral amino acid spacers - phenylalanine or proline - between the biotin anchor and the flexible aminodiphosphine moiety <b>1</b>, combined with saturation mutagenesis at position S112X of streptavidin, affords second generation artificial hydrogenases displaying improved organic solvent tolerance, reaction rates (3-fold) and (<i>S</i>)-selectivities (up to 95 % ee for <i>N</i>-acetamidoalanine and <i>N</i>-acetamidophenylalanine). It is shown that these artificial metalloenzymes follow Michaelis-Menten kinetics with an increased affinity for the substrate and a higher <i>k</i><sub>cat</sub> than the protein-free catalyst (compare <i>k</i><sub>cat</sub> 3.06 min<sup>-1</sup> and <i>K</i><sub>M</sub> 7.38 mM for [Rh(COD)<b>Biot-1</b>]<sup>+</sup> with <i>k</i><sub>cat</sub> 12.30 min<sup>-1</sup> and <i>K</i><sub>M</sub> 4.36 mM for [Rh(COD) <b>Biot-(<i>R</i>)-Pro-1</b>]<sup>+</sup> WT Sav). Finally, we present a straightforward protocol using Biotin-Sepharose to immobilize artificial metalloenzymes (>92 % ee for <i>N</i>-acetamidoalanine and <i>N</i>-acetamidophenylalanine using [Rh(COD) <b>Biot-(<i>R</i>)-Pro-1</b>]<sup>+</sup> Sav S112W).
Identifiants
Type de publication
journal article
