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Los grupos metilo del N-óxido de trimetilamina se orientan lejos de las interfaces hidrofóbicas
Laura B Sagle1, Katherine Cimatu, Vladislav A Litosh
1Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77843, USA.
Journal of the American Chemical Society
|October 5, 2011
Resumen
El N-óxido de trimetilamina (TMAO) orienta sus grupos metilo lejos de las superficies hidrofóbicas, lo que sugiere que su papel de estabilización de proteínas implica la exclusión preferencial de las interfaces. Esto afecta el plegamiento y la estabilidad de las proteínas.
Área de la Ciencia:
- Química biofísica y bioquímica.
- Ciencia de la interfaz Ciencia de la interfaz.
- Estabilización de las proteínas de estabilización.
Sus antecedentes:
- El N-óxido de trimetilamina (TMAO) es un conocido osmolito y estabilizador de proteínas.
- Comprender el comportamiento molecular en las interfaces es crucial para la estabilidad de las proteínas.
- La orientación de los osmolitos en las interfaces influye en sus interacciones con las biomoléculas.
Objetivo del estudio:
- Para investigar la orientación molecular del TMAO en las interfaces acuosas/hidrofóbicas.
- Para aclarar el papel de la estructura de TMAO en su comportamiento interfacial.
- Para conectar las propiedades interfaciales de TMAO con sus efectos estabilizadores de proteínas.
Principales métodos:
- Se empleó la espectroscopia de frecuencia de suma vibratoria (VSFS).
- Estudió la interfaz octadecyltrichlorosilane (OTS) / agua.
- Investigó la interfaz aire/agua con diferentes concentraciones de TMAO.
Principales resultados:
- Se observó que los grupos metilo de TMAO apuntaban hacia la fase acuosa, lejos de la interfaz OTS hidrofóbica.
- En la interfaz aire/agua, el TMAO mostró alineación, pero se encontró que estaba agotado, aumentando la tensión superficial.
- Incluso a altas concentraciones (5 M), los grupos OH colgantes del agua persistieron en la interfaz aire/agua.
Conclusiones:
- La orientación y el agotamiento de TMAO de las interfaces hidrofóbicas son impulsados por la naturaleza hidrófila de sus grupos metilo y óxido.
- El agotamiento observado sugiere una contribución entrópica al mecanismo de estabilización de proteínas de TMAO.
- La orientación molecular y la exclusión interfacial son factores clave en la capacidad de TMAO para estabilizar las estructuras de las proteínas.
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