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Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
Estudio computacional del estado fundamental de la síntesis de fosfato de indol glicerol termófilo: alteraciones
Devleena Mazumder-Shivakumar1, Kalju Kahn, Thomas C Bruice
1Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, USA.
Journal of the American Chemical Society
|May 13, 2004
Resumen
La actividad hipertermofílica de la indol-3-glicerol fosfato sintasa (IGPS) aumenta con la temperatura debido a los conformadores enzima-sustrato más reactivos. Este estudio revela la temperatura de las temperaturas.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Enzimología Enzimología.
- Biología computacional Biología computacional.
Sus antecedentes:
- La síntesis hipertermofílica de indol-3-glicerol fosfato (IGPS) es crucial para la biosíntesis del triptófano.
- Comprender la dinámica enzima-sustrato a diferentes temperaturas es clave para la función de las enzimas.
Objetivo del estudio:
- Para investigar los cambios estructurales del complejo enzima-sustrato con la temperatura.
- Para correlacionar la población de conformadores reactivos con las tasas de reacción.
Principales métodos:
- Se realizaron simulaciones de dinámica molecular (DM) en el sustrato unido a la enzima a 298 K y 385 K.
- El campo de fuerza CHARMM y el modelo de agua TIP3P se utilizaron para las simulaciones.
Principales resultados:
- Un aumento significativo (aprox. 1100 veces) en conformadores reactivos de enzima-sustrato (conformadores de ataque cercano, NACs) se observó a 385 K en comparación con 298 K.
- La población de NACs se correlacionó directamente con el aumento observado en la velocidad de reacción a temperaturas más altas.
- Los residuos del sitio activo Lys53 y Lys110 fueron identificados como críticos para orientar el sustrato para la catálisis.
Conclusiones:
- El aumento dependiente de la temperatura en los NAC facilita la catálisis ácida general en IGPS.
- La formación de NAC es un importante contribuyente a la dependencia de la temperatura de la energía libre de la reacción.
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