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Formación autoduplex de un oligodeoxyadenilato A(py) sustituido y su fluorescencia única
Young Jun Seo1, Hanju Rhee, Taiha Joo
1Department of Chemistry, BK School of Molecular Science, Pohang University of Science and Technology, Pohang 790-784, Korea.
Journal of the American Chemical Society
|March 31, 2007
Resumen
Las unidades de pireno unidas a la deoxyadenosina forman auto-duplexos inesperados de homoadenina, alterando la fluorescencia. Este conjunto de ácido nucleico cambia de color y emite una señal de fluorescencia roja única y de larga duración.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Química supramolecular de las moléculas.
Sus antecedentes:
- Los oligodeoxyadenilatos son cadenas cortas de ADN compuestas de bases de adenina.
- Las unidades de pireno se pueden incorporar a los ácidos nucleicos como sondas fluorescentes.
- El control del ensamblaje de ácido nucleico y las propiedades de fluorescencia es crucial para el diagnóstico molecular y la nanotecnología.
Objetivo del estudio:
- Para investigar la formación de nuevas estructuras de ácido nucleico impulsadas por intercaladores de pireno.
- Para explorar la relación entre la colocación de pireno y las propiedades de fluorescencia resultantes.
- Para caracterizar las características espectroscópicas y estructurales de los oligodeoxyadenilatos modificados por pireno.
Principales métodos:
- Adhesión covalente de las unidades de pireno a las bases de desoxyadenosina en los oligodeoxyadenilatos.
- Análisis espectroscópico que incluye UV-Vis, dicroísmo circular (CD) y espectroscopia de fluorescencia.
- Estudios de temperatura de fusión (Tm) y electroforesis en gel para evaluar la estabilidad estructural y el montaje.
- Mediciones de fluorescencia con resolución temporal mediante el conteo de fotones únicos correlacionados con el tiempo (TCSPC) y técnicas de conversión ascendente.
Principales resultados:
- Inesperados auto-duplexos intermoleculares de homoadenina se formaron cuando las unidades de pireno estaban a distancias específicas (1,4 relaciones).
- Una banda de fluorescencia rojiza única (pico a 580 nm) observada para dúplex con más de dos espacios entre las unidades de pireno.
- Los oligómeros mostraban colores de fluorescencia distintos (rojo-naranja, verde, azul) dependiendo de la ubicación del pireno.
- La fluorescencia roja única exhibió una larga vida útil, confirmada por mediciones con resolución de tiempo.
Conclusiones:
- Los intercaladores de pireno de pequeñas moléculas pueden inducir un nuevo autoensamblaje de ácido nucleico.
- La disposición específica de las unidades de pireno dicta la formación de auto-duplexos de homoadenina y la salida de fluorescencia.
- Este sistema impulsado por pireno ofrece una plataforma sintonizable para el ensamblaje de ácido nucleico con señales fluorescentes distintas.
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