Video Experimental Relacionado
Updated: Dec 15, 2025
11:54
Ligand-Mediated Nucleation and Growth of Palladium Metal Nanoparticles
Published on: June 25, 2018
10.7K
Cooperatividad alostérica y síntesis dirigida por plantilla con ligandos apilados en nanorredes de porfirina
Pernille S Bols1, Michel Rickhaus1, Lara Tejerina1
1Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom.
Journal of the American Chemical Society
|July 8, 2020
Resumen
Se estudió la cooperatividad alostérica en química supramolecular. La cooperatividad negativa obstaculizaba la síntesis de plantillas, mientras que la cooperatividad positiva la hacía posible, demostrando un vínculo entre la vinculación y la síntesis.
Área de la Ciencia:
- Química supramolecular
- Síntesis Química
- Química Física
Sus antecedentes:
- La cooperatividad alostérica describe cómo la unión de una molécula afecta la unión de otra.
- La síntesis dirigida por plantilla utiliza una plantilla para guiar la formación de un producto.
- Comprender la interacción entre estos fenómenos es crucial para el diseño de sistemas moleculares.
Objetivo del estudio:
- Investigar la relación entre la cooperatividad alostérica y la síntesis dirigida por plantilla.
- Para explorar cómo los diferentes modos de unión de ligandos influyen en la formación de nanos.
- Evaluar la eficacia de los ligandos como modelos basados en su cooperatividad.
Principales métodos:
- Estudio de complejos de nanoanillos de porfirina de zinc con ligandos de oligopiridina.
- Utilizando la titulación por desnaturalización UV-NIR para determinar las constantes de formación.
- El uso de la espectroscopia RMN para confirmar los factores de cooperatividad.
Principales resultados:
- Se observó una cooperatividad alostérica negativa (α ≈ 10^-3-10^-4) para los ligandos tridentados que se unen a una nanoreda de 6-porfirina, lo que dificulta la síntesis de la plantilla.
- Se observó una cooperatividad alostérica positiva (α > 40) para los ligandos hexadentados que se unen a una nanoreda de 12 porfirina, lo que permite una síntesis efectiva de la plantilla de Vernier.
- La cooperatividad negativa estaba vinculada a una disociación más rápida del complejo 1:2, mientras que la cooperatividad positiva facilitaba la formación de productos.
Conclusiones:
- El grado y el tipo de cooperatividad alostérica tienen un impacto directo en la eficacia de los ligandos como plantillas en la síntesis de nanorines.
- La cooperatividad positiva en plantillas de Vernier apiladas promueve la formación de macrociclos en una conformación circular abierta.
- Este enfoque ofrece ventajas para sintetizar macrociclos que se resisten a la adopción de geometrías específicas.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:58Cooperative Allosteric Transitions
8.5K
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
8.5K
01:58Cooperative Allosteric Transitions
2.6K
2.6K
00:49Ligand Binding and Linkage
5.4K
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence...
5.4K
01:19Allosteric Proteins-ATCase
6.3K
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
6.3K
02:51Metal-Ligand Bonds
23.4K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
23.4K
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
3.0K
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
3.0K