Related Experiment Video
Updated: Mar 9, 2026
11:44
Spin Saturation Transfer Difference NMR SSTD NMR: A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes
Published on: November 12, 2016
18.7K
Separating Dipolar and Chemical Exchange Magnetization Transfer Processes in 1 H-CEST
Tairan Yuwen1, Ashok Sekhar1, Lewis E Kay1,2
1Departments of Molecular Genetics, Biochemistry, and Chemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
Angewandte Chemie (International Ed. in English)
|December 31, 2016
Summary
A new amide proton Chemical Exchange Saturation Transfer (CEST) experiment enables precise studies of protein conformational exchange. This method suppresses NOE effects, accurately measuring millisecond-timescale dynamics and chemical shifts for minor protein conformers.
Area of Science:
- Biochemistry
- Structural Biology
- Biophysical Chemistry
Background:
- Protein conformational dynamics are crucial for function.
- Studying proteins in millisecond exchange requires specialized techniques.
- Existing methods like Nuclear Overhauser Effect (NOE) can complicate Chemical Exchange Saturation Transfer (CEST) measurements.
Purpose of the Study:
- To develop a novel amide proton 1H-CEST experiment for studying protein conformational exchange.
- To suppress Nuclear Overhauser Effect (NOE) interferences in CEST profiles.
- To accurately determine the chemical shifts and dynamics of minor protein conformers.
Main Methods:
- Development of a spin-state-selective magnetization transfer approach for 1H-CEST.
- Application of the method to proteins exhibiting millisecond-timescale conformational interconversion.
- Analysis of CEST profiles to extract chemical exchange parameters.
Main Results:
- The novel 1H-CEST experiment effectively suppresses NOE-based signal changes.
- Accurate amide 1H chemical shifts of minor protein conformers were obtained.
- The methodology successfully characterized proteins exchanging on the millisecond timescale.
Conclusions:
- The spin-state-selective magnetization transfer 1H-CEST approach is a powerful tool for studying protein conformational dynamics.
- This technique provides quantitative insights into protein exchange processes.
- Enables detailed structural and dynamic characterization of transient protein states.
Related Concept Videos
01:12Double Resonance Techniques: Overview
829
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
829
01:13¹H NMR: Complex Splitting
2.1K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
2.1K
01:13¹H NMR Signal Multiplicity: Splitting Patterns
7.8K
When protons A and X are coupled, their nuclear spin energy levels are slightly modified. This is because the energy required to excite proton A to a spin state parallel to proton X is slightly different from the energy required for it to become anti-parallel to spin X. Consequently, there are two possible excitation frequencies for A (A1 and A2), depending on the spin state of X, and vice versa. The mutual nature of coupling implies that the difference between frequencies A1 and A2, indicated...
7.8K
01:04¹³C NMR: ¹H–¹³C Decoupling
2.0K
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...
2.0K
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.7K
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...
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...
1.7K
01:182D NMR: Overview of Heteronuclear Correlation Techniques
849
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
849