Video Experimental Relacionado
Updated: Jul 20, 2026
08:09
15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the µs-ms Timescale
Published on: April 19, 2021
Espectroscopia de dispersión de relajación cuántica múltiple de RMN que sondea la dinámica de la escala de tiempo de
Dmitry M Korzhnev1, Karin Kloiber, Lewis E Kay
1Protein Engineering Network Centres of Excellence and the Department of Medical Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
Journal of the American Chemical Society
|June 10, 2004
Resumen
Nuevos experimentos de dinámica de proteínas exploran procesos de milisegundos utilizando la coherencia cuántica múltiple (1) H- ((15) N. Este método ofrece mediciones robustas de parámetros de intercambio, especialmente para las proteínas protonadas.
Área de la Ciencia:
- La biofísica es la biofísica.
- Biología Estructural Biología estructural.
- Dinámica de las proteínas Dinámica de las proteínas.
Sus antecedentes:
- La dinámica de las proteínas es crucial para la función.
- Los procesos a escala de tiempo de milisegundos son difíciles de estudiar.
- Los métodos convencionales tienen limitaciones para las proteínas protonadas.
Objetivo del estudio:
- Introducir nuevos experimentos de dispersión de relajación.
- Probe dinámicas de milisegundos en las proteínas.
- Mejorar la medición de los parámetros de intercambio.
Principales métodos:
- Medida (1) H-(15) N relajación de la coherencia cuántica múltiple.
- Utilice los pulsos de reenfoque (1) H o (15) N. Utilice pulsos de reenfoque (1) H o (15) N. Utilice pulsos de reenfoque (1) H o (15) N.
- Analizar los perfiles de dispersión de relajación cuántica única y múltiple.
Principales resultados:
- Las dispersiones cuánticas múltiples son sensibles a los entornos (1) H y (15) N.
- Los perfiles difieren de los experimentos de un solo cuántico.
- Se ha demostrado en el mutante del dominio Fyn SH3.
Conclusiones:
- El análisis combinado de perfiles cuánticos únicos y múltiples proporciona medidas robustas de parámetros de intercambio.
- El método es ventajoso para las proteínas protonadas.
- Aplicado con éxito para estudiar la dinámica de plegado/despliegue de proteínas.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:13¹H NMR: Complex Splitting
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 first.
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 first.
01:10¹H NMR of Labile Protons: Temporal Resolution
Protons bonded to heteroatoms such as nitrogen and oxygen exhibit a range of chemical shift values. This is due to the varying degree of hydrogen bonding between the proton and the heteroatom in other molecules. The extent of hydrogen bonding affects the electron density around the proton, thereby giving different chemical shift values for the protons in the proton NMR spectrum.
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
01:12Two-Dimensional (2D) NMR: Overview
The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
01:13¹H NMR Signal Multiplicity: Splitting Patterns
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...
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...
01:25Applications Of NMR In Biology
Nuclear magnetic resonance (NMR) spectroscopy is a very valuable analytical technique for researchers. It has been used for more than 50 years as an analytical tool. F. Bloch and E. Purcell formulated NMR in 1946 and won the 1952 Nobel Prize in Physics for their work. Biological macromolecules such as proteins, nucleic acids, lipids, and organic molecules including pharmaceutical compounds, can be studied using this versatile tool that exploits the magnetic properties of certain nuclei.
The...
The...