Video Experimental Relacionado

Updated: Jul 2, 2026

NMR 15N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins

NMR ¹⁵N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins

Published on: November 1, 2024

Cambios en la dinámica de SRE-RNA en la unión al dominio VTS1p-SAM estudiado por relajación de RMN 13C

Florian C Oberstrass¹, Frédéric H-T Allain, Sapna Ravindranathan

¹Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zürich, Switzerland.

Journal of the American Chemical Society

|August 14, 2008

Resumen

La unión a las proteínas altera la dinámica del ARN, haciendo que los movimientos sean más uniformes. Se observó una mayor flexibilidad en algunos sitios y rigidez en otros, junto con un sorprendente movimiento colectivo lento en el bolsillo de unión de la proteína.

Área de la Ciencia:

La bioquímica es la bioquímica.
Biología Molecular Biología Molecular
Biología Estructural Biología estructural.

Sus antecedentes:

Las interacciones proteína-ARN son cruciales para los procesos biológicos.
La dinámica del ARN influye significativamente en la unión y función de las proteínas.
Estudios limitados cuantifican los cambios de movimiento en el ARN tras la interacción con las proteínas.

Objetivo del estudio:

Para estudiar cuantitativamente los cambios en la dinámica del ARN (escalas de tiempo de pico-nanosegundos a micro-millisegundos) en la unión a las proteínas.
Para caracterizar el impacto de la interacción del dominio VTS1p-SAM en la dinámica SRE-ARN.
Investigar la relación entre la dinámica del ARN, la unión a las proteínas y la termodinámica.

Principales métodos:

Estudio cuantitativo (13) de relajación por RMN C. Estudio de relajación por RMN.
Análisis de formalismo libre de modelo de las tasas de relajación de (13) C.
Utilizado en su totalidad (13) C/(15) SRE-ARN etiquetado con N en estados libres y unidos a proteínas.

Principales resultados:

Diferencias distintivas de movimiento observadas entre las regiones del tallo y del bucle en el ARN libre.
La unión a las proteínas condujo a movimientos de ARN más homogéneos.
Aumento de la flexibilidad en los carbonos aromáticos y aumento de la rigidez en los carbonos anómeros al unirse.
Evidencia de un lento movimiento colectivo de ARN dentro del bolsillo de unión a las proteínas.

Conclusiones:

La unión a las proteínas homogeneiza la dinámica del ARN, alterando la flexibilidad en diferentes regiones.
El aumento observado en la dinámica de la unión desafía la noción de restricción de movimiento universal.
La ganancia de entropía del aumento del movimiento del ARN puede contribuir favorablemente a la energía libre de unión.

Más Videos Relacionados

Practical Aspects of Sample Preparation and Setup of 1H R1ρ Relaxation Dispersion Experiments of RNA

Practical Aspects of Sample Preparation and Setup of ¹H R_1ρ Relaxation Dispersion Experiments of RNA

Published on: July 9, 2021

15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the µs-ms Timescale

¹⁵N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the µs-ms Timescale

Published on: April 19, 2021

Videos de Conceptos Relacionados

Atomic Nuclei: Types of Nuclear Relaxation

Atomic Nuclei: Types of Nuclear Relaxation

Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...

¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR

¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR

The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.

NMR Spectroscopy: Spin–Spin Coupling

NMR Spectroscopy: Spin–Spin Coupling

The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved in...

RNA Stability

RNA Stability

Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...

RNA Stability

RNA Stability

Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...