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La transición del ADN G-cuadruplex desplegado al plegado analizado e interpretado por espectroscopia infrarroja

A Larasati Soenarjo¹, Zhihao Lan², Igor V Sazanovich³

¹Department of Chemistry, Imperial College London, White City Campus, London W12 0BZ, United Kingdom.

Journal of the American Chemical Society

|August 30, 2023

Resumen

Los G-cuadruplexos (G4) son estructuras de ADN cruciales para la regulación génica. Este estudio utilizó espectroscopia y cálculos avanzados para revelar el proceso de plegamiento paso a paso del ADN G4, identificando las interacciones moleculares clave involucradas en su formación.

Área de la Ciencia:

Biología molecular
La biofísica
Física Química

Sus antecedentes:

Los G-cuadruplexos (G4) son estructuras de ADN que se encuentran en regiones ricas en guanina.
El ADN G4 juega un papel en la transcripción genética y el mantenimiento de los telómeros, lo que lo convierte en un objetivo farmacológico.
Comprender las interacciones moleculares del G4-ADN es clave para el diseño racional de fármacos.

Objetivo del estudio:

Para investigar las interacciones moleculares que impulsan el plegamiento del ADN G-cuadruplex.
Para dilucidar la secuencia de plegado de una cadena paralela de G4-ADN utilizando métodos experimentales y computacionales.

Principales métodos:

Se utilizó la espectroscopia infrarroja bidimensional de vibración de electrones (EVV 2DIR) para medir los espectros de acoplamiento vibratorio.
Los cálculos químicos cuánticos utilizando la teoría funcional de la densidad (DFT) predijeron espectros de acoplamiento para elementos estructurales.
Los cambios estructurales durante el plegamiento del ADN G4 fueron monitoreados en función de la concentración de iones K+.

Principales resultados:

Se identificaron y rastrearon 102 picos de acoplamiento vibratorio durante el proceso de plegado.
Los fenómenos observados incluyen cambios de frecuencia, cambios de intensidad entre picos y nuevas apariciones de picos.
El estudio propone una secuencia de plegado para el Myc2345 G4-DNA en condiciones experimentales.

Conclusiones:

Los cuartetos de guanina pueden preexistir en la formación de G4-ADN pero permanecer sin apilar.
Los iones de potasio (K +) son cruciales para apilar estos cuartetos y formar la estructura completa G4.
La combinación de la espectroscopia EVV 2DIR y los cálculos DFT proporciona información sobre los mecanismos de plegamiento del ADN G4.

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