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Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Los enlaces de péptido único exhiben espectros de dicroísmo circulares de poli (pro) II ("bobina aleatoria")
Isa Gokce1, Robert W Woody, Gregor Anderluh
1Institute of Cell and Molecular Biosciences, University of Newcastle-upon-Tyne, Framlington Place, Newcastle-upon-Tyne NE2 4HH, UK.
Journal of the American Chemical Society
|July 7, 2005
Resumen
Los enlaces péptidos simples exhiben una conformación preferida, influyendo en el espectro de las proteínas desordenadas. Este hallazgo se deriva del análisis de los espectros de dicroísmo circular de los derivados de aminoácidos en la luz ultravioleta lejana.
Área de la Ciencia:
- Química biofísica y bioquímica.
- La espectroscopia es una técnica de espectroscopia.
- Estructura de las proteínas Estructura de las proteínas
Sus antecedentes:
- Los espectros de dicroísmo circular (CD) UV lejano de los polipéptidos son cruciales para comprender la estructura secundaria de las proteínas.
- La conformación poliprolina (PP) II es un estado desordenado común observado en las proteínas.
Objetivo del estudio:
- Para investigar las preferencias conformacionales de los enlaces péptidos simples utilizando la espectroscopia de CD UV lejano.
- Determinar la base estructural para el espectro característico PP II.
Principales métodos:
- Medición de espectros de dicroísmo circular de UV lejano para varios derivados de aminoácidos con enlaces peptídicos únicos.
- Análisis de los cambios espectrales al calentar para identificar las transiciones conformacionales.
Principales resultados:
- Los derivados de N-acetil-alanina y Gly-Ala exhibieron un espectro similar al de la poliprolina (PP) II.
- La alaninamida mostró una señal positiva débil, y Ala-Gly no mostró un espectro PP II.
- Se observó una transición de dos estados al calentar, consistente con los polipéptidos PP II.
Conclusiones:
- El máximo negativo característico de PP II a <200 nm surge del acoplamiento del enlace peptídico al N-terminal quiral alfa-carbono.
- Los enlaces péptidos más simples poseen una conformación preferida que dicta los espectros CD de las proteínas desordenadas, independientemente de su tamaño.
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