Video Experimental Relacionado

Updated: Jul 18, 2026

Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase

Protein Film Infrared Electrochemistry Demonstrated for Study of H₂ Oxidation by a [NiFe] Hydrogenase

Published on: December 4, 2017

Descomposición inducida por monóxido de carbono del sitio activo del grupo [Ni-4Fe-5S] de CO deshidrogenasa

Holger Dobbek¹, Vitali Svetlitchnyi, Jago Liss

¹Laboratorium für Proteinkristallographie, Universität Bayreuth, Bayreuth, Germany. Holger.Dobbeck@uni-bayreuth.de

Journal of the American Chemical Society

|April 29, 2004

Resumen

Las estructuras cristalinas revelan diferencias en los entornos de coordinación de Ni dentro de las deshidrogenasas de monóxido de carbono (CODH). El estudio muestra que el grupo [Ni-4Fe-4S] en CODHII es una forma inactiva derivada del grupo [Ni-4Fe-5S] activo.

Área de la Ciencia:

La bioquímica es la bioquímica.
Biología Estructural Biología estructural.
Enzimología Enzimología.

Sus antecedentes:

Se han reportado estructuras cristalinas de varias deshidrogenasas de monóxido de carbono (CODH) que contienen Ni, Fe y S.
Los CODH de bacterias anaerobias presentan un sitio activo de Cluster C con Ni, Fe y S, que muestra variaciones en los entornos de coordinación de Ni en diferentes especies.
Estudios anteriores destacaron similitudes estructurales en los pliegues de proteínas, pero diferencias significativas en la coordinación de Ni dentro del grupo C de CODHs de *Carboxydothermus hydrogenoformans*, *Rhodospirillum rubrum* y *Moorella thermoacetica*.

Objetivo del estudio:

Para aclarar la relación entre la estructura del grupo C en *Carboxydothermus hydrogenoformans* CODH II (CODHII(Ch)) y su funcionalidad proteica.
Investigar los cambios estructurales en CODHII ((Ch) bajo condiciones variables y su impacto en la actividad catalítica.

Principales métodos:

Determinó la actividad de oxidación de CO de CODHII ((Ch) bajo diferentes condiciones de cristalización.
Cristales de enzimas preparados que utilizan Dithiothreitol o Dithionite como agentes reductores bajo atmósferas de N ((2) o CO.
Estructuras cristalinas disueltas de CODHII ((Ch) a resoluciones que van desde 1.1 a 1.6 Å bajo diversas condiciones.

Principales resultados:

CODHII ((Ch) totalmente activo incubado con ditionita bajo N ((2) mostró el cúmulo [Ni-4Fe-5S] activo.
La exposición corta al CO con Dithiothreitol produjo CODHII ((Ch) catalíticamente competente con un grupo [Ni-4Fe-5S] reducido en CO.
El tratamiento prolongado con CO condujo a la pérdida de actividad y la formación de un racimo [Ni-4Fe-4S] inactivo que carecía de un ligando mu(2)-S, originario del racimo [Ni-4Fe-5S].

Conclusiones:

El grupo [Ni-4Fe-4S] en CODHII (Ch) representa un producto de descomposición inactivado del grupo [Ni-4Fe-5S] activo.
Las diferencias estructurales en los entornos de coordinación de Ni tienen un impacto significativo en la funcionalidad del CODH.
Comprender estas relaciones estructural-funcionales es crucial para los mecanismos de las enzimas CODH.

Más Videos Relacionados

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO₂ Reduction

Published on: April 10, 2018

Solar-Driven Electrochemical Green Fuel Production from CO2 and Water Using Ti3C2Tx MXene-Supported CuZn and NiCo Catalysts

Solar-Driven Electrochemical Green Fuel Production from CO₂ and Water Using Ti₃C₂T_x MXene-Supported CuZn and NiCo Catalysts

Published on: November 7, 2025

Videos de Conceptos Relacionados

Electron Transport Chains

Electron Transport Chains

The final stage of cellular respiration is oxidative phosphorylation that consists of two steps: the electron transport chain and chemiosmosis. The electron transport chain is a set of proteins found in the inner mitochondrial membrane in eukaryotic cells. Its primary function is to establish a proton gradient that can be used during chemiosmosis to produce ATP and generate electron carriers, such as NAD+ and FAD, that are used in glycolysis and the citric acid cycle.
The ETC is comprised of...

Catalysis

Catalysis

The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.

Oxidative Cleavage of Alkenes: Ozonolysis

Oxidative Cleavage of Alkenes: Ozonolysis

In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.

Role of Reduced Coenzymes NADH and FADH₂

Role of Reduced Coenzymes NADH and FADH₂

The energy released from the breakdown of the chemical bonds within nutrients can be stored either through the reduction of electron carriers or in the bonds of adenosine triphosphate (ATP). In living systems, a small class of compounds functions as mobile electron carriers, molecules that bind to and shuttle high-energy electrons between compounds in pathways. The principal electron carriers that will be considered originate from the B vitamin group and are derivatives of nucleotides; they are...

Electron Transport Chain: Complex III and IV

Electron Transport Chain: Complex III and IV

During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...

Carbon-dioxide Fixation

Carbon-dioxide Fixation

Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...