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Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
Hidrogenasa I ligada a la membrana de la bacteria hipertermófila Aquifex aeolicus: activación de enzimas, intermedios
Maria-Eirini Pandelia1, Vincent Fourmond, Pascale Tron-Infossi
1Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D45470, Mülheim a.d. Ruhr, Germany.
Journal of the American Chemical Society
|May 6, 2010
Resumen
La hidrogenasa ligada a la membrana de Aquifex aeolicus muestra una mayor tolerancia al oxígeno y una reactivación más rápida, lo que la hace mejor para la oxidación de H2. Sus interacciones del sitio activo con el oxígeno fueron detalladas utilizando espectroscopia avanzada.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Enzimología Enzimología.
- La biofísica es la biofísica.
Sus antecedentes:
- La hidrogenasa ligada a la membrana (Hase I) de Aquifex aeolicus es una enzima redox conocida por su alta termostabilidad y tolerancia al oxígeno.
- Comprender sus mecanismos catalíticos e interacciones con el oxígeno es crucial para las aplicaciones biotecnológicas.
Objetivo del estudio:
- Para investigar la interacción de Aquifex aeolicus Hase I con el oxígeno molecular.
- Para dilucidar los detalles estructurales y la química redox del sitio activo de la enzima.
- Comprender el mecanismo de inactivación y reactivación del oxígeno.
Principales métodos:
- La electroquímica de la película proteica se utilizó para estudiar la actividad catalítica y las interacciones del oxígeno.
- La espectroscopia de infrarrojos con transformación de Fourier (FTIR) junto con la electroquímica in situ identificaron detalles estructurales del sitio activo y estados redox.
Principales resultados:
- La coordinación del sitio activo [NiFe] es similar a la hidrogenasas estándar, con una fracción de Fe ((CN) ((2) CO conservada.
- Se detectaron cuatro intermedios catalíticos (Ni-B, Ni-SI(a), Ni-C, Ni-R, con potenciales de punto medio desplazados positivamente en comparación con las hidrogenasas mesófilas.
- El oxígeno inhibe la enzima formando un estado inactivo de Ni-B en el sitio activo, similar a la inactivación anaeróbica.
Conclusiones:
- Aquifex aeolicus Hase I es más adecuado para la oxidación de H2 que la producción debido a su potencial redox.
- La reactivación desde el estado inactivo de Ni-B es significativamente más rápida que en las hidrogenasas mesófilas, a pesar de la termodinámica desfavorable.
- El estudio proporciona información sobre el mecanismo enzimático y la tolerancia al oxígeno de esta hidrogenasa hipertermofílica.
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