Allosteric effects in organic chemistry: binding cooperativity in a model for subunit interactions

Rebek, Julius; Costello, T.; Marshall, L.; Wattley, R. V.; Gadwood, Robert C.; Onan, Kay D.

doi:10.1021/ja00311a043

Cited by 191 publications

(83 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…3 As another way to incorporate a crown-ether moiety to bpy, we focused our attention on 3,3′-disubstituted-2,2′-bipyridine (3,3′-R2-bpy) and its ruthenium(II) complex. [5][6][7][8] In free 3,3′-R2-bpy, the R orient to trans with respect to one another, owing to a steric hindrance between R. When 3,3′-R2-bpy coordinates to a ruthenium ion, its structure becomes more or less distorted from octahedral (Oh) symmetry because of a steric repulsion between the Rs. 5,6 Such a circumstance in the complex brings about a non-emissive or weakly emissive property.…”

Section: Introductionmentioning

confidence: 99%

Photochemical Ion Receptor Based on a Structurally Distorted Ruthenium(II) Complex Having a Crown-Ether Moiety at the 3,3′-Positions on the 2,2′-Bipyridine Ligand

2002

View full text Add to dashboard Cite

Ru(bpy)2(CE-bpy)2+ was prepared where bpy and CE-bpy were 2,2′-bipyridine and bpy having a crown-ether moiety at the 3,3′-positions, respectively. Although Ru(bpy)2(CE-bpy) 2+ showed only very weak emission in acetonitrile, recognition of Na + , Li + , or K + by the crown-ether moiety in CE-bpy resulted in increases in both the emission intensity and the lifetime of the complex, demonstrating that it acted as a photoreceptor. The results were discussed in terms of a steric hindrance between the 3,3′-substituents on CE-bpy and structural changes in both CE-bpy and the complex upon ion recognition, as studied by variable-temperature

show abstract

Section: Introductionmentioning

confidence: 99%

Photochemical Ion Receptor Based on a Structurally Distorted Ruthenium(II) Complex Having a Crown-Ether Moiety at the 3,3′-Positions on the 2,2′-Bipyridine Ligand

2002

View full text Add to dashboard Cite

show abstract

“…Over the years, a large number of artificial receptors displaying positive (5)(6)(7)(8) and negative (9)(10)(11) homotropic and positive (12)(13)(14)(15)(16)(17)(18)(19)(20) and negative (21)(22)(23) heterotropic cooperative binding phenomena have been developed. Although in many cases the origins of the cooperative effects could be identified, few studies have dealt in detail with the kinetics and thermodynamics of such complicated multicomponent receptor-guest systems.…”

mentioning

confidence: 99%

Squaring cooperative binding circles

Deutman

Monnereau

Moalin

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The cooperative binding effects of viologens and pyridines to a synthetic bivalent porphyrin receptor are used as a model system to study how the magnitudes of these effects relate to the experimentally obtained values. The full thermodynamic and kinetic circles concerning both activation and inhibition of the cage of the receptor for the binding of viologens were measured and evaluated. The results strongly emphasize the apparent character of measured binding and rate constants, in which the fractional saturation of receptors with other guests is linearly expressed in these constants. The presented method can be used as a simple tool to better analyze and comprehend the experimentally observed kinetics and thermodynamics of natural and artificial cooperative systems.kinetics ͉ slippage ͉ supramolecular chemistry ͉ thermodynamics C ooperative binding plays an important role in nature, where it is used to construct well-defined assemblies and is used as a tool to transfer information at the cellular level (1). The formation of the tobacco mosaic virus (2) and the binding of oxygen to hemoglobin (3) are 2 well-known examples of cooperative processes. Cooperative binding interactions can be homotropic or heterotropic, when the combined binding to a multivalent receptor involves the same or different types of guests. In additions, these interactions can be positive or negative, when the binding of a guest promotes or obstructs the binding of a second guest (4).One of the challenges in the field of supramolecular chemistry is to design artificial systems that display cooperative binding effects, not only to better understand the mechanisms involved in the natural processes but also to prepare functional materials and catalysts that benefit from such binding interactions. Over the years, a large number of artificial receptors displaying positive (5-8) and negative (9-11) homotropic and positive (12-20) and negative (21-23) heterotropic cooperative binding phenomena have been developed. Although in many cases the origins of the cooperative effects could be identified, few studies have dealt in detail with the kinetics and thermodynamics of such complicated multicomponent receptor-guest systems. This is surprising, because unlike the complex biological systems, the artificial receptor-guest systems can be easily studied, and the fine details of cooperative behavior can be uncovered. It is generally known that measured association constants are context dependent in the sense that apparent values that depend on, e.g., the solvent system, salt concentrations, pH, and in the worst case impurities, are obtained (4). As a consequence, the observed cooperative binding effects might often deviate from the intrinsic ones.To investigate how the measured cooperative binding effects as derived from the observed experimental binding constants are related to the intrinsic ones, we present a detailed study of the combined binding of viologens and pyridines to the bivalent zinc porphyrin receptor Zn1 (24, 25) (Scheme 1). Pyridine ligan...

show abstract

“…Many cyclic polyethers were formed starting from 2,2'-dihydroxybiphenyl; [1][2][3] their coordination with organic cations like tert-butylammonium was studied, 2 as well as the transport of Li, Na, K cations 4,5 and of Hg(CF 3 ) 2 6,7 through a liquid membrane. In such macrocycles one or two polyoxaethylene chains were attached to one biphenyl unit.…”

Section: Introductionmentioning

confidence: 99%

Pd-catalyzed amination of dibromobiphenyls in the synthesis of macrocycles comprising two biphenyl and two polyamine moieties

Uglov¹,

Averin²,

Buryak³

et al. 2011

Arkivoc

View full text Add to dashboard Cite

Dedicated to Prof. Usein M. Dzhemilev on the occasion of his 65 th anniversaryAbstract Two approaches to the synthesis of polyazamacrocycles containing two biphenyl and two polyamine moieties are described. The first route comprises the synthesis of N,N'-bis(bromobiphenyl) substituted di-and poly-amines by the reactions of 2.2-3 equivalents of 4,4'-or 3,3'-dibromobiphenyls with corresponding di-and polyamines followed by the reaction with a second molecule of the amine. The second approach includes the synthesis of bis(polyamine) substituted biphenyls by the reactions of 4,4'-or 3,3'-dibromobiphenyls with four equivalents of di-and poly-amines with subsequent reaction of these in situ prepared intermediates with dibromobiphenyls. The yields of target macrocycles obtained according to two routes are compared and the advantage of the approach via bis(polyamine) substituted biphenyls in the majority of cases is established. Side products, when formed in all reactions, were analyzed.

show abstract

Allosteric effects in organic chemistry: binding cooperativity in a model for subunit interactions

Cited by 191 publications

References 0 publications

Photochemical Ion Receptor Based on a Structurally Distorted Ruthenium(II) Complex Having a Crown-Ether Moiety at the 3,3′-Positions on the 2,2′-Bipyridine Ligand

Photochemical Ion Receptor Based on a Structurally Distorted Ruthenium(II) Complex Having a Crown-Ether Moiety at the 3,3′-Positions on the 2,2′-Bipyridine Ligand

Squaring cooperative binding circles

Pd-catalyzed amination of dibromobiphenyls in the synthesis of macrocycles comprising two biphenyl and two polyamine moieties

Contact Info

Product

Resources

About