Video Experimental Relacionado
Updated: Jul 16, 2025
14:44
Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
9.6K
Efectos de las esferas de coordinación primaria y secundaria en la estructura y función de la azurina nitrosilante
Casey Van Stappen1, Huiguang Dai1,2, Anex Jose3
1Department of Chemistry, University of Texas at Austin, 105 E 24th St., Austin, Texas 78712, United States.
Journal of the American Chemical Society
|September 11, 2023
Resumen
La esfera de coordinación secundaria tiene un impacto en la reactividad de la proteína de cobre en la S-nitrosilación (SNO). Los investigadores identificaron factores clave como la fuerza del enlace Cu-S y la localización del espín que gobiernan la eficiencia de esta modificación biológica crucial.
Área de la Ciencia:
- La bioquímica
- Química bioorgánica
- Química de las metaloproteínas
Sus antecedentes:
- Se conocen las funciones de la esfera de coordinación secundaria (SCS) en los potenciales redox de las metaloproteínas, pero se comprende menos el impacto en la reactividad.
- Las proteínas de cobre catalizan la S-nitrosilación (SNO), una modificación vital después de la traducción que regula el óxido nítrico.
- Los factores que permiten la nitrosilación y la actividad moduladora de Cu (II) S siguen sin estar claros.
Objetivo del estudio:
- Investigar la influencia de la SCS en la S-nitrosilación catalizada por Cu (II).
- Desarrollar variantes de azurina para sondear las relaciones estructura-actividad.
- Elucidar el mecanismo molecular de la catálisis del SNO por proteínas de cobre.
Principales métodos:
- Se utilizaron variantes de azurina con actividad catalítica modulada.
- Se emplean espectroscopias de absorción electrónica, XAS (borde S y Cu K), EPR y de resonancia Raman.
- Se realizó un análisis computacional QM/MM para vincular estructura y mecanismo.
Principales resultados:
- Se identificaron tres factores clave que se correlacionan con la competencia cinética: la fuerza del enlace Cu-S, la localización del espín Cu y las contribuciones S ((p_s) / S ((p_p).
- Apoyó una vía de reacción que involucra el ataque de enlaces Cu-S, no mecanismos electrofílicos o radicales.
- Se estableció un vínculo entre la estructura de la proteína y la actividad catalítica del SNO.
Conclusiones:
- Obtuvo una visión más profunda de los mecanismos biológicos SNO.
- Proporcionó una base para el diseño de enzimas SNO artificiales.
- Ofreció una base para el desarrollo de estrategias terapéuticas contra las enfermedades relacionadas con la desregulación del SNO.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:202° Amines to N-Nitrosamines: Reaction with NaNO2
4.3K
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
4.3K
02:34Structural Isomerism
19.3K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
19.3K
02:57Coordination Number and Geometry
15.9K
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
15.9K
03:02Colors and Magnetism
11.8K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
11.8K
01:371° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
3.8K
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
3.8K
02:51Metal-Ligand Bonds
20.9K
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...
20.9K