Video Experimental Relacionado
Updated: May 10, 2026
12:47
Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins
Published on: December 27, 2016
Medición de los equilibrios de ionización del sitio activo en la partícula central del proteosoma de 670 kDa
Algirdas Velyvis1, Lewis E Kay
1Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8. avelyvis@pound.med.utoronto.ca
Journal of the American Chemical Society
|June 27, 2013
Resumen
El proteosoma 20S es el proteosoma 20S.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Biología Estructural Biología estructural.
Sus antecedentes:
- La partícula central del proteosoma 20S regula la función celular a través de la proteólisis.
- Es un objetivo farmacológico clave para las terapias contra el cáncer.
- La comprensión de los mecanismos de escisión del sustrato es crucial para el desarrollo farmacéutico.
Objetivo del estudio:
- Para aclarar el papel de Thr1 en el mecanismo catalítico del proteasoma 20S.
- Para identificar la base responsable de aceptar el protón Thr1 durante la escisión del enlace péptido.
Principales métodos:
- Utilizó una muestra de proteasoma 20S altamente deuterada.
- Incorporado (13) CH3 etiquetado en las posiciones Thr-gamma.
- Se midió el pKa del grupo amino Thr1.
Principales resultados:
- El pKa del grupo amino Thr1 se determinó como 6.3.
- Esto indica que el grupo amino Thr1 se desprotona durante la actividad enzimática máxima.
- Proporciona evidencia de que el grupo amino Thr1 actúa como la base catalítica.
Conclusiones:
- El grupo amino terminal de Thr1 actúa como la base en el paso inicial de la escisión del enlace peptídico por el proteosoma 20S.
- Este hallazgo aclara un aspecto clave del mecanismo catalítico del proteasoma.
- Informa el diseño de nuevos fármacos dirigidos al proteasoma.
Más Videos Relacionados
10:28Measuring Interactions of Globular and Filamentous Proteins by Nuclear Magnetic Resonance Spectroscopy (NMR) and Microscale Thermophoresis (MST)
Published on: November 2, 2018
16:40T-wave Ion Mobility-mass Spectrometry: Basic Experimental Procedures for Protein Complex Analysis
Published on: July 31, 2010
Videos de Conceptos Relacionados
01:17The Proteasome Structure
The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
The proteasome is an...
The proteasome is an...
01:33Proteomics
A proteome is the entire set of proteins that a cell type produces. We can study proteomes using the knowledge of genomes because genes code for mRNAs, and the mRNAs encode proteins. Although mRNA analysis is a step in the right direction, not all mRNAs are translated into proteins.
Proteomics is the study of proteomes' function. It involves the large-scale systematic study of the proteome to denote the protein complement expressed by a genome. Scientist Mark Wilkins coined the term proteomics...
Proteomics is the study of proteomes' function. It involves the large-scale systematic study of the proteome to denote the protein complement expressed by a genome. Scientist Mark Wilkins coined the term proteomics...
01:03¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons
Protons in identical electronic environments within a molecule are chemically equivalent and have the same chemical shift. The replacement test is a useful tool to identify chemical equivalence and predict NMR spectra. A substituent replaces each of the protons being examined and the resulting molecules are compared. If the same molecule is obtained, the protons are equivalent or homotopic. Replacement of any hydrogens in ethane by chlorine yields chloroethane because all six protons are...
01:07Proton (¹H) NMR: Chemical Shift
Organic molecules primarily contain carbon and hydrogen atoms. While all the hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant. It has a significant energy separation between its nuclear spin states due to its large gyromagnetic ratio. As per Boltzmann's distribution, an increase in the energy separation implies a greater excess population of nuclei available for excitation, resulting in a strong NMR absorption signal.
Absorption signals of all the protium nuclei in a...
Absorption signals of all the protium nuclei in a...
01:19NMR Spectroscopy Of Amines
In proton NMR spectroscopy, primary amines and secondary amines showcase their N–H protons as a broad signal in the chemical shift range between δ 0.5 and 5 ppm. The exact position in this range depends on several factors, including sample concentration, hydrogen bonding, and the type of solvent used. Since amine protons undergo fast proton exchange in solution, the protons are labile and therefore do not participate in any splitting with adjacent protons. Thus, the observed peak is broad and...
01:13Mass Spectrometry: Isotope Effect
Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the mass differences between isotopes. Furthermore, the intensity of these signals is dependent on the...