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Mecanismo catalítico de la hidrolasa de epóxido de limoneno, un estudio teórico de estudio
Kathrin H Hopmann1, B Martin Hallberg, Fahmi Himo
1Theoretical Chemistry, Department of Biotechnology, Royal Institute of Technology, AlbaNova University Center, SE-106 91 Stockholm, Sweden.
Journal of the American Chemical Society
|October 13, 2005
Resumen
Este estudio revela el mecanismo catalítico de la hidrolasa de epóxido de limoneno (LEH) utilizando métodos computacionales. LEH utiliza una catálisis general concertada ácido/base para la producción de limoneno-1,2-diol a partir de limoneno-1,2-epoxido.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Enzimología Enzimología.
- Química computacional es la química computacional.
Sus antecedentes:
- La hidrolasa de epóxido de limoneno (LEH) es clave en una nueva vía de degradación del limoneno en Rhodococcus erythropolis DCL14.
- El LEH cataliza la hidrólisis del limoneno-1,2-epoxido hasta el limoneno-1,2-diol.
Objetivo del estudio:
- Para dilucidar el mecanismo catalítico de la hidrolasa de epóxido de limoneno (LEH).
- Para explicar la regioselectividad observada en la hidrólisis de estereoisómeros de epóxido de limoneno.
Principales métodos:
- Investigación teórica utilizando la teoría funcional de la densidad (DFT) con el método B3LYP.
- Modelado del sitio activo de LEH basado en la estructura cristalina, incluyendo aminoácidos clave (Asp101, Asp132) y una molécula de agua.
Principales resultados:
- El mecanismo catalítico implica una catálisis general ácido/base concertada.
- Asp101 protona el sustrato, mientras que Asp132 extrae un protón de la molécula de agua atacante.
- El modelo explica la hidrólisis regioselectiva experimentalmente observada de los estereoisómeros de limoneno-1,2-epoxido.
Conclusiones:
- LEH emplea un mecanismo catalítico específico que involucra residuos de ácido y base para la hidrólisis de epoxidos.
- Los hallazgos proporcionan información molecular sobre la función y la especificidad de LEH en el metabolismo del limoneno.
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