Haute école pédagogique du canton de Vaud

Utilisation de TICE dans l'enseignement de la chimie au secondaire 2 : mise en oeuvre, apports, contraintes et évaluation

Delval, Franck ; Gradinaru, Julieta ; Donzé, Laurent (Dir.)

Mémoire de Master Advanced Studies (MAS) : Haute école pédagogique du canton de Vaud, 2017 ; mp7119.

Dans ce travail, nous nous intéressons à l’utilisation de Technologies de l’Information et de la Communication dans l’Enseignement (TICE) dans l'enseignement de la chimie au secondaire 2, particulièrement pour des classes de première année maturité. Partant du constat que l’abstraction des phénomènes rencontrés en chimie, due à l'échelle infiniment petite où ils s’y...

Université de Neuchâtel

(Strept)avidin as Host for Biotinylated Coordination Complexes: Stability, Chiral Discrimination, and Cooperativity

Loosli, Andreas ; Rusbandi, Untung Edy ; Gradinaru, Julieta ; Bernauer, Klaus ; Schlaepfer, Carl Wilhelm ; Meyer, Michel ; Mazurek, Sylwester ; Novic, Marjana ; Ward, Thomas R.

In: Inorganic Chemistry, 2006, vol. 45, no. 2, p. 660-668

To determine the stepwise association constants, to assess cooperativity and chiral discrimination properties of (strept)avidin toward biotinylated coordination complexes, diastereopure [Ru(bpy)2(Biot-bpy)]2+ (1) complexes were synthesized. Analysis of the CD titration data suggests a strong cooperativity between the first and the second binding events in tetrameric...

Université de Neuchâtel

Artificial Metalloenzymes: (Strept)avidin as Host for Enantioselective Hydrogenation by Achiral Biotinylated Rhodium−Diphosphine Complexes

Skander, Myriem ; Humbert, Nicolas ; Collot, Jérôme ; Gradinaru, Julieta ; Klein, Gérard ; Loosli, Andreas ; Sauser, Jérôme ; Zocchi, Andrea ; Gilardoni, François ; Ward, Thomas R.

In: Journal of the American Chemical Society (JACS), 2004, vol. 126, no. 44, p. 14411–14418

We report on the generation of artificial metalloenzymes based on the noncovalent incorporation of biotinylated rhodium−diphosphine complexes in (strept)avidin as host proteins. A chemogenetic optimization procedure allows one to optimize the enantioselectivity for the reduction of acetamidoacrylic acid (up to 96% ee (R) in streptavidin S112G and up to 80% ee (S) in WT avidin)....

Université de Neuchâtel

Artificial Metalloenzymes for Enantioselective Catalysis Based on Biotin−Avidin

Collot, Jérôme ; Gradinaru, Julieta ; Humbert, Nicolas ; Skander, Myriem ; Zocchi, Andrea ; Ward, Thomas R.

In: Journal of the American Chemical Society (JACS), 2003, vol. 125, no. 30, p. 9030-9031

Incorporation of biotinylated racemic three-legged d6-piano stool complexes in streptavidin yields enantioselective transfer hydrogenation artificial metalloenzymes for the reduction of ketones. Having identified the most promising organometallic catalyst precursors in the presence of wild-type streptavidin, fine-tuning of the selectivity is achieved by saturation mutagenesis at...

Université de Fribourg

(Strept)avidin as host for biotinylated coordination complexes: stability, chiral discrimination, and cooperativity

Loosli, Andreas ; Rusbandi, Untung Edy ; Gradinaru, Julieta ; Bernauer, Klaus ; Schlaepfer, Carl Wilhelm ; Meyer, Michel ; Mazurek, Sylwester ; Novic, Marjana ; Ward, Thomas R.

In: Inorganic Chemistry, 2006, vol. 45, no. 2, p. 660 -668

Incorporation of a biotinylated ruthenium tris(bipyridine) [Ru(bpy)₂(Biot-bpy)]²⁺ (1) in either avidin or streptavidin-(strept)avidin-can be conveniently followed by circular dichroism spectroscopy. To determine the stepwise association constants, cooperativity, and chiral discrimination properties, diastereopure (Λ and δ)-1 species were synthesized and incorporated in...

Université de Neuchâtel

Hierarchical Self-Assembly of One-Dimensional Streptavidin Bundles as a Collagen Mimetic for the Biomineralization of Calcite

Burazerovic, Sabina ; Gradinaru, Julieta ; Pierron, Julien ; Ward, Thomas R.

In: Angewandte Chemie International Edition, 2007, vol. 46, no. 29, p. 5510-5514

We report on our efforts to create efficient artificial metalloenzymes for the enantioselective hydrogenation of N-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 1, combined with saturation mutagenesis at...