Looking for the Origin of Allosteric Cooperativity in Metallopolymers. Issue 24 (3rd May 2016)

• Record Type: Journal Article
• Authors: Babel, Lucille; Hoang, Thi Nhu Y; Guénée, Laure; Besnard, Céline; Wesolowski, Tomasz A.; Humbert‐Droz, Marie; Piguet, Claude
• Is Part Of: Chemistry. Volume 22:Issue 24(2016)
• Page Start: 8113
• Page End: 8123
• Publication Date: 2016-05-03
• Subjects: cooperativity -- host–guest systems -- lanthanides -- metallopolymers -- solvation; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201600857
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The basic concept of allosteric cooperativity used in biology, chemistry and physics states that any change in the intermolecular host–guest interactions operating in multisite receptors can be assigned to intersite interactions. Using lanthanide metals as guests and linear multi‐tridentate linear oligomers of variable lengths and geometries as hosts, this work shows that the quantitative modeling of metal loadings requires the consideration of a novel phenomenon originating from solvation processes. It stepwise modulates the intrinsic affinity of each isolated site in multisite receptors, and this without resorting to allosteric cooperativity. An easy‐to‐handle additive model predicts a negative power law dependence of the intrinsic affinity on the length of the linear metallopolymer. Applied to lanthanidopolymers, the latter common analysis overestimates cooperativity factors by more than two orders of magnitude. Abstract : Make it right : Taking the affinity of a monomeric host as a reference for the estimation of intersite interactions in related oligomers and polymers may overestimate allosteric cooperativity (see figure) by more than two orders of magnitude! A simple power‐law dependence on the total number of binding sites introduces a pertinent correction for the rationalization of metal loading in lanthanidopolymers.