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Aromatización enzimática de piridina durante la biosíntesis de tiopéptidos
Andrew J Rice1,2, Jarrett M Pelton3, Nicholas J Kramer3
1Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States.
Journal of the American Chemical Society
|November 9, 2022
Resumen
Los investigadores aclararon el mecanismo de formación de piridina en las pirítidas (tiopéptidos) que contienen tiazol. Se identificó un residuo crítico de tirosina, que facilita el paso final de aromatización en esta vía biosintética compleja.
Área de la Ciencia:
- La bioquímica
- Biología molecular
- Síntesis de productos naturales
Sus antecedentes:
- Los pirítidos que contienen tiazol, o tiopéptidos, son péptidos complejos sintetizados por ribosoma y modificados post-traduccionalmente (RiPP) conocidos por sus potentes bioactividades.
- Una característica estructural clave es un heterociclo de piridina formado a través de la cicloadición enzimática [4 + 2], aunque su mecanismo de formación sigue sin estar claro.
Objetivo del estudio:
- Investigar el mecanismo poco conocido de la formación de anillos de piridina en la biosíntesis del tiopéptido.
- Identificar los residuos y las etapas clave involucradas en la vía enzimática de síntesis de piridina.
Principales métodos:
- Se utilizaron mutagénesis dirigida y ensayos cinéticos para estudiar las tiopéptidas piridinas.
- Se han empleado análogos de sustratos, enlaces entre enzimas y sustratos y experimentos de rescate químico.
- Construido sobre la identificación del intermediario Bycroft-Gowland.
Principales resultados:
- Delineó las funciones de varios residuos conservados en las tiopeptidas piridina sintasas.
- Se identificó un residuo crítico de tirosina esencial para la etapa final de aromatización de la formación de piridina.
- Proporcionó información mecanicista sobre la [4 + 2]-cicloadición y la posterior síntesis de piridina.
Conclusiones:
- Se estableció un marco mecanicista para la formación de tiopéptido piridina.
- Destacó el papel crucial de una tirosina específica en el proceso de aromatización.
- Estableció las bases para futuras investigaciones sobre la biosíntesis y la ingeniería de tiopéptidos.
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