Loosli, Andreas Rusbandi, Untung Edy Gradinaru, Julieta Bernauer, Klaus Schläpfer, Carl-Wilhelm Meyer, Michel Mazurek, Sylwester Novic, Marjana Ward, Thomas R. 2005-12-24 Incorporation of a biotinylated ruthenium tris(bipyridine) [Ru(bpy)₂(Biot-bpy)]²⁺ (<b>1</b>) 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)-<b>1 </b>species were synthesized and incorporated in tetrameric (strept)avidin to afford (δ-[Ru(bpy)₂(Biot-bpy)]²⁺)<i>_x</i>⊂avidin, (Λ- [Ru(bpy)₂(Biot-bpy)]²⁺)<i>_x</i>⊂avidin, (δ-[Ru(bpy)₂(Biot- bpy)]²⁺)<i>_x</i>⊂streptavidin, and (Λ-[Ru(bpy)₂(Biot-bpy)]²⁺) <i>_x</i>⊂streptavidin (<i>x</i> = 1-4) For these four systems, the overall stability constants are log <i>β</i>₄ = 28.6, 30.3, 36.2, and 36.4, respectively. Critical analysis of the CD titrations data suggests a strong cooperativity between the first and the second binding event (<i>x</i> = 1, 2) and a pronounced difference in affinity between avidin and streptavidin for the dicationic guest <b>1 </b>as well as modest enantiodiscrimination properties with avidin as host. application/pdf https://folia.unifr.ch/global/documents/300492 https://folia.unifr.ch/documents/300492/files/schlaepfer_shb.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1021/ic051405t info:eu-repo/semantics/openAccess License undefined Inorganic Chemistry. - 2006, vol. 45, no. 2, p. 660-668 info:eu-repo/classification/udc/54 (Strept)avidin as host for biotinylated coordination complexes: stability, chiral discrimination, and cooperativity http://purl.org/coar/resource_type/c_6501