Video Experimental Relacionado

Updated: Apr 14, 2026

Thermostabilization, Expression, Purification, and Crystallization of the Human Serotonin Transporter Bound to S-citalopram

Thermostabilization, Expression, Purification, and Crystallization of the Human Serotonin Transporter Bound to S-citalopram

Published on: November 27, 2016

La base estructural de la unión ordenada al sustrato por la serotonina N-acetiltransferasa: complejo enzimático a una

A B Hickman¹, M A Namboodiri, D C Klein

¹Laboratory of Developmental Neurobiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-0560, USA.

|May 13, 1999

Resumen

Este estudio revela cómo la serotonina N-acetiltransferasa se une a la acetilcoenzima A, causando un cambio conformacional que crea el sitio de unión de la serotonina. Las perspectivas estructurales también destacan un canal de agua y el Tyr-168.

Área de la Ciencia:

La bioquímica es la bioquímica.
Biología Estructural Biología estructural.
Cronobiología cronobiología.

Sus antecedentes:

La serotonina N-acetiltransferasa (SNAT) es crucial para la síntesis de la melatonina.
La melatonina regula el ritmo circadiano.
SNAT pertenece a la superfamilia de las acetiltransferasas GNAT.

Objetivo del estudio:

Para aclarar la base estructural de la actividad de SNAT.
Comprender el mecanismo de unión al acetil-CoA y la formación del sitio de unión a la serotonina.
Para investigar el papel catalítico de los residuos específicos.

Principales métodos:

Cristalografía de rayos X de SNAT sin sustrato y ligado analógico.
Comparación estructural de diferentes estados enzimáticos.
Mutagénesis dirigida al sitio.

Principales resultados:

La unión de la acetil coenzima A (AcCoA) induce un cambio conformacional significativo en el SNAT.
Este cambio conduce a la formación del sitio de unión de la serotonina.
Un canal lleno de agua y Tyr-168 están implicados en la catálisis.

Conclusiones:

La flexibilidad conformacional de SNAT es clave para su funcionamiento.
La enzima utiliza características estructurales específicas para facilitar la transferencia de acetilo y la eliminación de protones.
Tyr-168 juega un papel crítico en el mecanismo catalítico de SNAT.

Más Videos Relacionados

A Plate-Based Assay for the Measurement of Endogenous Monoamine Release in Acute Brain Slices

A Plate-Based Assay for the Measurement of Endogenous Monoamine Release in Acute Brain Slices

Published on: August 11, 2021

Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET

Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET

Published on: October 9, 2021

Videos de Conceptos Relacionados

Induced-fit Model

Induced-fit Model

Most chemical reactions in cells require enzymes—biological catalysts that speed up the reaction without being consumed or permanently changed. They reduce the activation energy needed to convert the reactants into products. Enzymes are proteins, that usually work by binding to a substrate—a reactant molecule that they act upon.
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical...

Ligand Binding and Linkage

Ligand Binding and Linkage

Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence...

SN2 Reaction: Stereochemistry

S_N2 Reaction: Stereochemistry

In an SN2 reaction, the nucleophilic attack on the substrate and departure of the leaving group occurs simultaneously through a transition state. As the nucleophile approaches the substrate from the back-side, the configuration of the substrate carbon changes from tetrahedral to trigonal bipyramidal and then back to tetrahedral, leading to an inversion in the configuration of the product.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...

SN1 Reaction: Kinetics

S_N1 Reaction: Kinetics

In an SN2 reaction, the reaction rate depends on both the type of nucleophile and the substrate. A hindered tertiary alkyl halide is practically inert to the SN2 mechanism despite using a strong nucleophile.
However, Sir Christopher Ingold and Edward D. Hughes, who studied the kinetics of various nucleophilic substitution reactions, noticed that a tertiary alkyl halide does undergo a nucleophilic substitution reaction in the presence of a weak nucleophile. While studying the substitution...

Allosteric Proteins-ATCase

Allosteric 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...

Adrenergic Agonists: Chemistry and Structure-Activity Relationship

Adrenergic Agonists: Chemistry and Structure-Activity Relationship

Adrenergic agonists' structure-activity relationship (SAR) determines their selectivity and efficacy. These agonists comprise a phenylethylamine moiety with an aromatic ring and an ethylamine side chain.
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of...