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Synthesis and Mass Spectrometry Analysis of Oligo-peptoids
Published on: February 21, 2018
Oligo ((4-aminopiperidina-4-ácido carboxílico): un oligopéptido básico inusual con una conformación helicoidal
Joon-il Cho1, Masahiro Tanaka, Sota Sato
1Department of Chemistry and Biotechnology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Journal of the American Chemical Society
|September 4, 2010
Resumen
El oligopéptido básico Api(8) forma una estructura helicoidal en condiciones ácidas. Su conformación helicoidal se rompe en el pH alcalino debido a las interacciones del grupo de piperidina, lo que afecta a la unión de hidrógeno de la columna vertebral del péptido.
Área de la Ciencia:
- Química del péptido Química del péptido
- Química supramolecular de las moléculas.
- Química biofísica y bioquímica.
Sus antecedentes:
- Las conformaciones helicoidales en los polipéptidos suelen estabilizarse mediante enlaces de hidrógeno.
- Los polipéptidos básicos con cadenas laterales cargadas a menudo mantienen estructuras helicoidales a través de varios niveles de pH.
- El aminoácido no natural 4-aminopiperidina-4-ácido carboxílico (Api) presenta propiedades estructurales únicas.
Objetivo del estudio:
- Para investigar el comportamiento conformacional dependiente del pH del oligopéptido básico Api(8).
- Para aclarar el papel del residuo de ácido 4-aminopiperidina-4-carboxílico (Api) en la estructura Api.
- Comprender los mecanismos moleculares subyacentes a la inducción helicoidal y la ruptura en Api (8).
Principales métodos:
- Síntesis y caracterización del oligopéptido Api (8).
- La titulación alcalina para monitorear los cambios conformacionales con el pH.
- Espectroscopia de Resonancia Magnética Nuclear (RMN) para sondear las interacciones estructurales.
Principales resultados:
- Api ((8) adopta una conformación helicoidal exclusivamente en medios ácidos.
- La ruptura de la estructura helicoidal se observó en el rango de pH de 7-10.
- Los estudios de RMN sugieren que los grupos de piperidina no protonados interfieren con el enlace de hidrógeno necesario para la formación de hélices.
Conclusiones:
- La conformación helicoidal de Api ((8) es críticamente dependiente del estado de protonación de sus residuos Api.
- Las interacciones del grupo piperidina en los residuos Api no protonados desestabilizan la estructura helicoidal.
- La protonación o la acilación de grupos de piperidina puede inducir o estabilizar la estructura helicoidal de Api (8).
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