Video Experimental Relacionado
Updated: Jun 29, 2026
10:07
Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance
Published on: August 26, 2025
Dinámica de la unión de ligando de la dispersión de relajación de RMN 13C en abundancia natural
John S Zintsmaster1, Brian D Wilson, Jeffrey W Peng
1Department of Chemistry and Biochemistry, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, Indiana 46556, USA.
Journal of the American Chemical Society
|October 7, 2008
Resumen
Carr-Purcell-Meiboom-Gill (CPMG) 13Calpha La dispersión de relajación de RMN mide la dinámica de los ligandos durante la unión al receptor sin etiquetado de isótopos. Este método revela regiones de ligandos flexibles, lo que ayuda a comprender las complejas relaciones de formación y actividad.
Área de la Ciencia:
- La biofísica es la biofísica.
- Biología Química Biología química.
- Biología Estructural Biología estructural.
Sus antecedentes:
- Comprender la dinámica de los ligandos en la unión al receptor es crucial para el descubrimiento de fármacos.
- El etiquetado de isótopos para el análisis de ligandos es a menudo poco práctico en entornos farmacéuticos.
- La espectroscopia de Resonancia Magnética Nuclear (RMN) ofrece una visión de la dinámica molecular.
Objetivo del estudio:
- Para demostrar la utilidad de la dispersión de relajación de RMN 13Calpha de Carr-Purcell-Meiboom-Gill (CPMG) para perfilar la dinámica del ligando.
- Para validar la aplicabilidad del método en la abundancia natural de 13C.
- Para establecer relaciones de flexibilidad-actividad en las interacciones ligando-receptor.
Principales métodos:
- Utilizando las mediciones de dispersión de relajación de RMN CPMG 13Calpha.
- Realizar experimentos con abundancia natural de 13C para evitar el etiquetado de isótopos.
- Analizando la modulación de desplazamiento químico de los núcleos del ligando 13Calpha al momento de la unión.
Principales resultados:
- La dispersión de RMN de CPMG 13Calpha perfila efectivamente la dinámica de los ligandos durante la unión al receptor.
- El método identifica con éxito ángulos de torsión flexibles (por ejemplo, psi, chi1) que influyen en la formación de complejos.
- Viabilidad demostrada incluso sin una estructura receptora conocida.
- Aplicado para estudiar la unión del ligando fosfo-peptídico a Pin1.
Conclusiones:
- La dispersión de relajación de RMN CPMG 13Calpha es una herramienta práctica para estudiar la dinámica de los ligandos en la investigación farmacéutica.
- La técnica proporciona información valiosa sobre las relaciones entre la flexibilidad y la actividad.
- Permite la caracterización de eventos de unión de ligandos sin enriquecimiento isotópico o información estructural.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:28Atomic 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...
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...
01:04¹³C NMR: ¹H–¹³C Decoupling
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
01:10Carbon-13 (¹³C) NMR: Overview
Carbon-13 is a naturally occurring NMR-active isotope of carbon with a low natural abundance of 1.1%. In contrast, carbon-12 is the most abundant isotope of carbon with zero nuclear spin. Therefore, it is NMR inactive. The gyromagnetic ratio of carbon-13 is smaller than that of protons. As a result, carbon-13 resonance is about 6000 times weaker than proton resonance. For a given magnetic field strength, the resonance frequency of carbon-13 is about one-fourth of the resonance frequency for...
02:18The Equilibrium Binding Constant and Binding Strength
The equilibrium binding constant (Kb) quantifies the strength of a protein-ligand interaction. Kb can be calculated as follows when the reaction is at equilibrium:
00:52¹H 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...