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Assessing Energy Substrate Oxidation In Vitro with 14CO2 Trapping
Published on: March 23, 2022
Descubrimiento de un túnel de acceso de sustrato formado dinámicamente en el monóxido de carbono
Po-hung Wang1, Maurizio Bruschi, Luca De Gioia
1Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom.
Journal of the American Chemical Society
|May 30, 2013
Resumen
Los investigadores descubrieron un canal oculto y dinámico utilizado por el dióxido de carbono (CO2) para llegar a los sitios activos de la enzima. Este canal, formado por el movimiento de proteínas, guía el CO2 y asegura el transporte direccional de su producto, el monóxido de carbono (CO).
Área de la Ciencia:
- Bioquímica y Biología Molecular.
- La biofísica computacional es una biofísica computacional.
Sus antecedentes:
- El transporte de ligandos a los sitios activos de proteínas es crucial para los procesos biológicos y las enfermedades.
- Comprender estos mecanismos de transporte es clave para la función de las enzimas y el diseño de fármacos.
Objetivo del estudio:
- Para investigar el transporte de pequeños ligandos, específicamente CO2, al sitio activo del complejo enzimático de monóxido de carbono deshidrogenasa/acetil-CoA sintasa (CODH/ACS).
- Para dilucidar el mecanismo de los canales formados dinámicamente dentro de las proteínas para la difusión de ligandos.
Principales métodos:
- Utilizó un modelo de difusión-reacción.
- Empleó dinámicas moleculares y cálculos de la teoría funcional de densidad.
- Estructuras de rayos X analizadas para identificar la dinámica de las proteínas y la formación de canales.
Principales resultados:
- Se desentrañó un canal de gas formado dinámicamente para la difusión de CO2 al grupo C de CODH/ACS.
- Identificó los residuos His113 y His116 que controlan el transporte de ligandos en una escala de tiempo de milisegundos.
- Transporte direccional de CO demostrado desde el clúster C de CODH al clúster A de ACS a través de una red reforzada de enlaces de hidrógeno.
Conclusiones:
- Las proteínas pueden formar canales transitorios y escurridizos para el transporte eficiente de pequeños ligandos.
- La enzima CODH/ACS utiliza un canal dinámico para la entrada de CO2 y asegura una salida unidireccional de CO2.
- Esto proporciona un modelo general de cómo las proteínas grandes guían a los ligandos pequeños a los sitios activos.
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