Video Experimental Relacionado
Updated: Jun 28, 2026
07:56
Utilizing Time-Resolved Protein-Induced Fluorescence Enhancement to Identify Stable Local Conformations One α-Synuclein Monomer at a Time
Published on: May 30, 2021
Efectos alostéricos en la disociación del sustrato del citocromo P450 3A4 en nanodiscos observados por espectroscopia
Abhinav Nath1, Peter K Koo, Elizabeth Rhoades
1Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA.
Journal of the American Chemical Society
|November 5, 2008
Resumen
Los estudios de fluorescencia de una sola molécula revelan cómo los efectores influyen en la cinética de la enzima citocromo P450 (CYP) 3A4. Los efectores pueden retrasar la liberación de sustratos, lo que potencialmente mejora el metabolismo de los medicamentos.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Enzimología Enzimología.
- Farmacología Farmacología.
Sus antecedentes:
- El citocromo P450 (CYP) 3A4 es una enzima crucial para el metabolismo de fármacos en humanos.
- El CYP3A4 exhibe una cinética alostérica compleja debido a múltiples sitios de unión para sustratos y efectores.
Objetivo del estudio:
- Para investigar los mecanismos alostéricos del CYP3A4 utilizando fluorescencia de una sola molécula.
- Para medir el efecto de la alfa-nafthoflavona en el tiempo de residencia del tinte rojo del Nilo en el CYP3A4.4.
Principales métodos:
- Se utilizó la microscopía de fluorescencia de reflexión interna total.
- Empleó Nanodiscos de lípidos inmovilizados en superficie para incorporar el CYP3A4.4.
- Tiempos de residencia de una sola molécula medidos del tinte fluorescente Nile Red.
Principales resultados:
- Se ha demostrado que los efectores de CYP3A4 pueden disminuir las tasas de desviación del sustrato.
- Proporcionó evidencia directa para la modulación del efector de la cinética de la enzima.
- Cambios observados en los tiempos de residencia del rojo del Nilo en presencia de alfa-nafthoflavona.
Conclusiones:
- Los métodos de una sola molécula ofrecen poderosos conocimientos sobre los mecanismos alostéricos del CYP.
- La disminución de las tasas de eliminación del sustrato presenta un mecanismo potencial para el metabolismo mejorado por el efector.
- Los hallazgos contribuyen a comprender el metabolismo de los fármacos y la regulación de las enzimas.
Videos de Conceptos Relacionados
01:08Allosteric Regulation
Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or...
01:58Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
01:58Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
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.
01:19Protein Dynamics in Living Cells
Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET.
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...