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Cicloadiciones dinámicamente complejas [6+4] y [4+2] en la biosíntesis de Spinosyn A

Ashay Patel¹, Zhuo Chen², Zhongyue Yang¹

¹Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095-1569, United States.

Journal of the American Chemical Society

|February 25, 2016

Resumen

La enzima SpnF cataliza una reacción compleja de Diels-Alder. Los cálculos cuánticos revelan vías dinámicas paso a paso y un intermedio entrópico, que ofrece nuevos conocimientos sobre la catálisis enzimática.

Área de la Ciencia:

La bioquímica
Enzimología
Química computacional

Sus antecedentes:

SpnF es una enzima crucial para la biosíntesis de la espinosina A.
Cataliza una reacción transanular de Diels-Alder, una transformación química compleja.

Objetivo del estudio:

Para aclarar el mecanismo de reacción de SpnF utilizando métodos computacionales.
Investigar el papel de los efectos dinámicos en las cicloadiciones catalizadas por enzimas.

Principales métodos:

Se emplearon cálculos mecánicos cuánticos.
Se realizaron simulaciones dinámicas moleculares.

Principales resultados:

La reacción de Diels-Alder catalizada por SpnF no es puramente concertada o escalonada.
Un estado de transición ambimodal conduce tanto a ciclos de carga observados [4+2] como a los no observados [6+4].
Se identificaron vías dinámicamente escalonadas que involucran un "intermedio entrópico" y un reordenamiento de Cope.

Conclusiones:

El control enzimático de las reacciones puede implicar efectos dinámicos no estadísticos.
Comprender estas dinámicas proporciona nuevas perspectivas sobre las estrategias catalíticas de las enzimas.

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