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Formation of Ordered Biomolecular Structures by the Self-assembly of Short Peptides
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Oligómeros peptoides con cadenas laterales alfa-quirales y aromáticas: requisitos de secuencia para la formación de
1Department of Chemical Engineering, Northwestern University, Evanston, Illinois 60208, USA.
Journal of the American Chemical Society
|July 13, 2001
Resumen
Las glicinas (peptoides) sustituidas por oligo-N pueden formar hélices quirales estables cuando el N se sustituye con cadenas laterales específicas. Al menos un 50% de residuos quirales aromáticos y un residuo quiral en el extremo C son claves para la formación estable de hélices peptoides.
Área de la Ciencia:
- Química sintética es la química sintética.
- Se trata de una química supramolecular.
- Los biomateriales son biomateriales.
Sus antecedentes:
- Las glicinas (peptoides) sustituidas por oligo-N carecen de enlaces de hidrógeno en la columna vertebral, lo que dificulta la formación de una estructura alfa-helical.
- Los peptoides con cadenas laterales quirales y aromáticas específicas sustituidas por N pueden formar hélices estables, quirales, similares a la poliprolina.
- Estas hélices peptoides exhiben espectros de dicroísmo circular (CD) intensos similares a las hélices alfa de péptidos.
Objetivo del estudio:
- Investigar los factores relacionados con la secuencia que influyen en la formación de hélices peptoides estables.
- Determinar el porcentaje mínimo de residuos aromáticos quirales requeridos para la estructura helicoidal.
- Identificar los motivos de secuencia que estabilizan estas hélices peptoides quirales.
Principales métodos:
- Síntesis y caracterización de más de 30 peptoides heterooligoméricos.
- Espectroscopia de dicroísmo circular (CD) para evaluar la estructura helicoidal.
- Estudios de RMN 1H-13C HSQC para analizar la estructura y la estabilidad.
Principales resultados:
- Una composición de al menos 50% de residuos alfa-quirales y aromáticos es necesaria para una estructura helicoidal estable en los peptoides hexaméricos.
- Un residuo aromático quiral en el extremo carboxílico estabiliza significativamente las hélices peptoides cortas.
- El patrón de residuos aromáticos con una periodicidad triple crea una "cara aromática", estabilizando aún más la hélice.
- Las longitudes de la cadena más allá de 12-15 residuos reducen el impacto de la colocación de residuos, pero no el porcentaje en la estabilidad.
Conclusiones:
- Las estructuras helicoidales quirales estables se pueden diseñar en oligómeros peptoides a través de la ingeniería estratégica de la cadena lateral.
- El porcentaje y la ubicación de los residuos alfa-quirales y aromáticos son elementos de diseño críticos para los peptoides helicoidales.
- Estos hallazgos proporcionan información para el diseño de peptoides biomiméticos con estructuras secundarias predecibles.
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