Related Experiment Video
Updated: Jun 15, 2025

Author Spotlight: Exploring Intrinsically Disordered Protein Dynamics Through NMR Relaxation Experiments
Published on: November 1, 2024
Existence of Singularities in NMR Relaxation Dispersion Profiles: Implications for Hidden Dynamics
1NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701-4907, United States.
Abstract:
It is common for NMR relaxation dispersion experiments to suggest an absence of dynamics despite anecdotal indications of conformational dynamics. We explore the potential explanations and approaches to this conundrum. Some inconsistencies have been observed between two relaxation dispersion experiments, Carr-Purcell-Meiboom-Gill (CPMG) and adiabatic relaxation dispersion experiments, in recent dynamic studies of different biomolecules. Theoretical analyses show that such seemingly paradoxical results might come from a complex exchange topology that is concealed by the application of the simple two-site exchange model for interpretation of the relaxation dispersion data. Scenarios are explored and revealed in which the presence of complex millisecond conformational exchange could suppress the amplitude of CPMG relaxation dispersion profiles, even when the exchange rates are within the detectable range of the experiments. With experimental errors, the suppressed relaxation dispersion profiles could lead to the conclusion of "no millisecond conformational exchange". However, such hidden dynamics can potentially be detected by adiabatic relaxation dispersion experiments. Finally, we demonstrate some advantages of adiabatic relaxation dispersion experiments over conventional relaxation dispersion experiments and a simplified computational approach to analyze the adiabatic relaxation dispersion profiles.
More Related Videos
Related Concept Videos
¹H NMR: Interpreting Distorted and Overlapping Signals
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...
Atomic Nuclei: Types of Nuclear Relaxation
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...
NMR Spectrometers: Resolution and Error Correction
¹³C NMR: ¹H–¹³C Decoupling
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
Two-Dimensional (2D) NMR: Overview
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

