Formación de enlaces cruzados His-Cys post-traducionales en la tirosinasa inducida por las especies de cobre (II) -peroxo
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Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Nobutaka Fujieda1, Takuya Ikeda, Michiaki Murata
1Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
Journal of the American Chemical Society
|January 12, 2011
Resumen
La formación autocatalítica del enlace cruzado His-Cys en la tirosinasa (Aspergillus oryzae) ocurre cuando la apoenzima es tratada con cobre (II) aeróbicamente. Se propone que un intermediario de peróxido de dicobre (II) sea crucial para esta reacción.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Enzimología Enzimología.
- Química de las metaloproteínas.
Sus antecedentes:
- La tirosinasa es una enzima que contiene cobre crucial para la biosíntesis de la melanina.
- La comprensión de los mecanismos catalíticos de la tirosinasa es esencial para diversas aplicaciones biotecnológicas.
Objetivo del estudio:
- Para dilucidar el mecanismo de la formación de enlaces cruzados His-Cys autocatalíticos en Aspergillus oryzae tirosinasa.
- Para identificar los intermediarios reactivos clave involucrados en el proceso de activación de la enzima.
Principales métodos:
- Tratamiento de la apoenzima tirosinasa con Cu (II) bajo condiciones aeróbicas.
- Análisis espectroscópicos y cinéticos para caracterizar los intermediarios de reacción.
Principales resultados:
- Demostración de la formación autocatalítica del enlace cruzado His-Cys en el sitio activo de la tirosinasa.
- La evidencia sugiere la participación de una especie (μ-η(2):η(2)-peroxo) dicopro (II) como un intermediario clave.
Conclusiones:
- El estudio revela un nuevo mecanismo autocatalítico para el enlace cruzado His-Cys en la tirosinasa.
- El dicopro (II) peroxido intermedio propuesto ofrece información sobre la activación del cobre y el oxígeno en las metalloenzimas.
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