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The flexibility–complementarity dichotomy in receptor–ligand interactions
Synthetic supramolecular complexes provide an opportunity for quantitative systematic exploration of the relationship between chemical structure and molecular recognition phenomena. A family of closely related zinc porphyrin–pyridine complexes was used to examine the interplay of conformational flex...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Royal Society of Chemistry
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5811160/ https://www.ncbi.nlm.nih.gov/pubmed/29560233 http://dx.doi.org/10.1039/c4sc03398a |
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author | Sun, Hongmei Hunter, Christopher A. Llamas, Eva Marina |
author_facet | Sun, Hongmei Hunter, Christopher A. Llamas, Eva Marina |
author_sort | Sun, Hongmei |
collection | PubMed |
description | Synthetic supramolecular complexes provide an opportunity for quantitative systematic exploration of the relationship between chemical structure and molecular recognition phenomena. A family of closely related zinc porphyrin–pyridine complexes was used to examine the interplay of conformational flexibility and geometric complementarity in determining the selectivity of molecular recognition events. The association constants of 48 zinc porphyrin–pyridine complexes were measured in two different solvents, toluene and 1,1,2,2-tetrachloroethane (TCE). These association constants were used to construct 32 chemical double mutant cycles to dissect the free energy contributions of intramolecular H-bonds between the phenol side arms of the porphyrins and the ester or amide side arms of the pyridine ligands. Effective molarities (EM) for the intramolecular interactions were determined by comparison with the corresponding intermolecular H-bonding interactions. The values of EM do not depend on the solvent and are practically identical for amide and ester H-bond acceptors located at the same site on the ligand framework. However, there are variations of an order of magnitude in EM depending on the flexibility of the linker used to connect the H-bond acceptors to the pyridine ligands. Rigid aromatic linkers give values of EM that are an order of magnitude higher than the values of EM for the corresponding ester linkers, which have one additional torsional degree of freedom. However, the most flexible ether linkers give values of EM that are also higher than the values of EM for the corresponding ester linkers, which have one less torsional degree of freedom. Although the penalty for conformational restriction on binding is higher for the more flexible ether linkers, this flexibility allows optimization of the geometric complementarity of the ligand for the receptor, so there is a trade off between preorganization and fit. |
format | Online Article Text |
id | pubmed-5811160 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Royal Society of Chemistry |
record_format | MEDLINE/PubMed |
spelling | pubmed-58111602018-03-20 The flexibility–complementarity dichotomy in receptor–ligand interactions Sun, Hongmei Hunter, Christopher A. Llamas, Eva Marina Chem Sci Chemistry Synthetic supramolecular complexes provide an opportunity for quantitative systematic exploration of the relationship between chemical structure and molecular recognition phenomena. A family of closely related zinc porphyrin–pyridine complexes was used to examine the interplay of conformational flexibility and geometric complementarity in determining the selectivity of molecular recognition events. The association constants of 48 zinc porphyrin–pyridine complexes were measured in two different solvents, toluene and 1,1,2,2-tetrachloroethane (TCE). These association constants were used to construct 32 chemical double mutant cycles to dissect the free energy contributions of intramolecular H-bonds between the phenol side arms of the porphyrins and the ester or amide side arms of the pyridine ligands. Effective molarities (EM) for the intramolecular interactions were determined by comparison with the corresponding intermolecular H-bonding interactions. The values of EM do not depend on the solvent and are practically identical for amide and ester H-bond acceptors located at the same site on the ligand framework. However, there are variations of an order of magnitude in EM depending on the flexibility of the linker used to connect the H-bond acceptors to the pyridine ligands. Rigid aromatic linkers give values of EM that are an order of magnitude higher than the values of EM for the corresponding ester linkers, which have one additional torsional degree of freedom. However, the most flexible ether linkers give values of EM that are also higher than the values of EM for the corresponding ester linkers, which have one less torsional degree of freedom. Although the penalty for conformational restriction on binding is higher for the more flexible ether linkers, this flexibility allows optimization of the geometric complementarity of the ligand for the receptor, so there is a trade off between preorganization and fit. Royal Society of Chemistry 2015-02-01 2014-12-15 /pmc/articles/PMC5811160/ /pubmed/29560233 http://dx.doi.org/10.1039/c4sc03398a Text en This journal is © The Royal Society of Chemistry 2015 http://creativecommons.org/licenses/by/3.0/ This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0) |
spellingShingle | Chemistry Sun, Hongmei Hunter, Christopher A. Llamas, Eva Marina The flexibility–complementarity dichotomy in receptor–ligand interactions |
title | The flexibility–complementarity dichotomy in receptor–ligand interactions
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title_full | The flexibility–complementarity dichotomy in receptor–ligand interactions
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title_fullStr | The flexibility–complementarity dichotomy in receptor–ligand interactions
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title_full_unstemmed | The flexibility–complementarity dichotomy in receptor–ligand interactions
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title_short | The flexibility–complementarity dichotomy in receptor–ligand interactions
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title_sort | flexibility–complementarity dichotomy in receptor–ligand interactions |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5811160/ https://www.ncbi.nlm.nih.gov/pubmed/29560233 http://dx.doi.org/10.1039/c4sc03398a |
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