Video Experimental Relacionado
Updated: Jul 10, 2026
05:19
Rapid Glyco-Qualitative Assessment of Recombinant Proteins Using a Fully Automated System
Published on: June 28, 2024
Inhibición distintiva de las isoformas del caso O-GlcNAc por un tiolsulfonato alfa-GlcNAc
Eun J Kim1, Benjamin Amorelli, Mohannad Abdo
1Laboratory of Cell Biochemistry and Biology, NIDDK, National Institute of Health, Bethesda, Maryland 20892, USA.
Journal of the American Chemical Society
|November 13, 2007
Resumen
La O-GlcNAcase corta (OGA) es resistente a los inhibidores comunes, a diferencia de la OGA larga. Un nuevo inhibidor, el alfa-GlcNAc tiolsulfonato (2), se dirige selectivamente a la OGA corta e inhibe irreversiblemente la OGA larga.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Enzimología Enzimología.
- Biología celular Biología celular.
Sus antecedentes:
- O-GlcNAcase (OGA) regula el metabolismo de O-GlcNAc, que es crucial para los procesos celulares.
- El OGA humano existe como dos variantes de empalme: el OGA largo (con dominio HAT) y el OGA corto (sin dominio HAT).
- Las funciones de la OGA corta y el papel del dominio HAT en la catálisis de la OGA son en gran medida desconocidas.
Objetivo del estudio:
- Para investigar las características enzimáticas de OGA corto.
- Para identificar inhibidores selectivos para el corto OGA.
- Para dilucidar los diferentes mecanismos de inhibición de las variantes OGA.
Principales métodos:
- Ensayos de inhibición enzimática utilizando inhibidores conocidos de la OGA (PUGNAc, NAG-tiazolina).
- Prueba de alfa-GlcNAc tiolsulfonato (2) como un inhibidor potencial para las dos variantes de OGA.
- Análisis de la interacción del inhibidor con las variantes OGA, incluidos los estudios de modificación covalente.
Principales resultados:
- El OGA corto muestra resistencia a PUGNAc y NAG-tiazolina, a diferencia del OGA largo.
- El alfa-GlcNAc tiolsulfonato (2) es un potente inhibidor de las OGA cortas (Ki = 10 microM) con selectividad sobre las OGA largas y las hexosaminidasas.
- El inhibidor 2 modifica irreversiblemente el OGA largo a través de la unión covalente al dominio HAT, alterando su actividad y la escisión de la caspasa-3.
Conclusiones:
- El dominio HAT influye en la sensibilidad al inhibidor de la OGA.
- Alfa-GlcNAc tiolsulfonato (2) ofrece un enfoque inhibidor selectivo para el corto OGA.
- Los diferentes mecanismos de inhibición resaltan distintas funciones funcionales y posibilidades regulatorias para las variantes de empalme OGA.
Videos de Conceptos Relacionados
01:19Allosteric Proteins-ATCase
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
01:30Enzyme Inhibition
Inhibitors are molecules that reduce enzyme activity by binding to the enzyme. In a normally functioning cell, enzymes are regulated by a variety of inhibitors. Drugs and other toxins can also inhibit enzymes. Some inhibitors bind to the enzyme’s active site, while others inhibit enzymatic activity by binding to other sites on the protein structure.
01:18Indirect-Acting Cholinergic Agonists: Mechanism of Action
Indirect-acting cholinergic agonists work by interacting with an enzyme called acetylcholinesterase (AChE) in the synaptic cleft. They can be reversible or irreversible inhibitors and have different effects on the enzyme.
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
01:24Acetals and Thioacetals as Protecting Groups for Aldehydes and Ketones
Acetals are formed by reacting two equivalents of alcohol with carbonyl compounds like aldehydes or ketones. Acetals are unaffected by bases, nucleophiles, oxidizing agents, and reducing agents. They serve as protecting groups for aldehydes and ketones. Acetals can be easily formed and also easily removed via mild acid hydrolysis.
In the presence of multiple functional groups, when selective reduction of one group over the other is desired, groups like aldehydes and ketones that form acetals...
In the presence of multiple functional groups, when selective reduction of one group over the other is desired, groups like aldehydes and ketones that form acetals...
01:29Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
Indirect-acting cholinergic agonists are agents that interact with the acetylcholinesterase enzyme in the synaptic cleft, preventing the breakdown of acetylcholine into choline and acetate. Consequently, the concentration of acetylcholine in the synaptic cleft increases. These agonists can be classified into reversible and irreversible inhibitors based on their duration of action.
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...