Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

¹H NMR: Interpreting Distorted and Overlapping Signals01:02

¹H 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...
NMR Spectroscopy: Spin–Spin Coupling01:08

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...
Atomic Nuclei: Nuclear Spin State Overview01:03

Atomic Nuclei: Nuclear Spin State Overview

NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule01:10

Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule

In the AX proton spin system, proton A can sense the two spin states of a coupled proton X, resulting in a doublet NMR signal with two peaks of equal (1:1) intensity. When proton A is coupled to two equivalent protons (AX2 spin system), the spin states of each X can be aligned with or against the external field, creating three possible scenarios. This results in a 1:2:1  triplet signal, where the central peak corresponds to the chemical shift of A and is twice as large or intense as the others.
¹³C NMR: ¹H–¹³C Decoupling01:04

¹³C 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...
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Genetically Encoding Propiolamide Warhead for the Construction of Phage Displayed Cyclic Peptide Library.

Chembiochem : a European journal of chemical biology·2026
Same author

Quantum transduction from electron spin state to a signaling state in a wild-type LOV photoreceptor.

bioRxiv : the preprint server for biology·2026
Same author

Visualizing and Braking Protein Ring Flips with Difluorotyrosines.

Analytical chemistry·2026
Same author

Transmembrane Domain Oligomerization and Intracellular Domain-Lipid Interaction Oppositely Modulates OX40 Receptor Activation Unveiled by <sup>19</sup>F NMR.

Journal of the American Chemical Society·2026
Same author

Trityl-Nitroxide Triradicals for Efficient High-Field Dynamic Nuclear Polarization.

Analytical chemistry·2026
Same author

Beyond a Passive Tether: Structural Insights into the Disordered Tail of Hsp90.

Journal of the American Chemical Society·2026

Related Experiment Video

Updated: Jun 3, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
14:55

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy

Published on: September 17, 2017

Unlocking Gd(III) Anisotropy: Determining the Zero-Field Splitting Axes to Enhance Spin-Label Structural Analysis.

Alexey Bogdanov1, Veronica Frydman2, Xun-Cheng Su3

  • 1Department of Chemical and Biological Physics, The Weizmann Institute of Science, P.O. Box 26, Rehovot 7610001, Israel.

Journal of the American Chemical Society
|June 2, 2026
PubMed
Summary
This summary is machine-generated.

Determining zero-field splitting (ZFS) orientation in Gadolinium(III) complexes is crucial for magnetic resonance. This study introduces a new method using electron-nuclear double resonance (ENDOR) to directly measure ZFS orientation in Gd(III) spin labels.

More Related Videos

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
11:19

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels

Published on: July 4, 2016

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
08:53

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092

Published on: October 2, 2017

Related Experiment Videos

Last Updated: Jun 3, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
14:55

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy

Published on: September 17, 2017

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
11:19

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels

Published on: July 4, 2016

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
08:53

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092

Published on: October 2, 2017

Area of Science:

  • Magnetic Resonance
  • Structural Biology
  • Quantum Chemistry

Background:

  • Zero-field splitting (ZFS) of Gadolinium(III) complexes is vital for magnetic resonance imaging (MRI), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and Gd-based spin labeling in structural biology.
  • Determining the molecular-frame orientation of the ZFS tensor in Gd(III) chelate complexes in frozen solution is challenging due to experimental and computational demands, compounded by structural and dynamic heterogeneity.

Purpose of the Study:

  • To introduce an experimental strategy for direct determination of the ZFS tensor orientation in Gd(III) complexes.
  • To enable accurate quantitative analysis of Gd(III) anisotropy and improve structure determination using Gd-based labels.
  • To provide benchmarks for quantum-chemical predictions of ZFS tensors.

Main Methods:

  • Utilized orientation-selective (OS) electron-nuclear double resonance (ENDOR) with 19F and 1H.
  • Employed a dual-mode analysis of Gd-F ENDOR spectra, measuring electron-nuclear distances at the Gd(III) central transition and Gd-F vector orientation using OS-ENDOR on high-|mS| transitions.
  • Applied a simple molecular modeling calculation based on the electric-field-gradient tensor for theoretical comparison.

Main Results:

  • Successfully determined the molecular-frame ZFS orientation for commonly used Gd-DO3A and Gd-PyMTA spin labels.
  • Accurately extracted electron-nuclear distances and determined Gd-F vector orientations.
  • Identified the location of Gd-DO3A labels in two 19F-containing proteins, revealing that existing rotamer libraries overestimate conformational distributions.
  • Experimentally determined ZFS orientations were compared with theoretical predictions.

Conclusions:

  • The developed experimental strategy enables direct determination of ZFS tensor orientation in Gd(III) complexes.
  • This method facilitates improved structure determination using Gd-based labels and provides critical data for refining quantum-chemical predictions.
  • The findings highlight limitations of current rotamer libraries for modeling Gd-based label conformations.