Video Experimental Relacionado
Updated: Jul 11, 2026
14:39
Measuring Phagosome pH by Ratiometric Fluorescence Microscopy
Published on: December 7, 2015
Estructura del canal iónico 1 sensible al ácido con una resolución de 1,9 A y un pH bajo
Jayasankar Jasti1, Hiroyasu Furukawa, Eric B Gonzales
1Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA.
Nature
|September 21, 2007
Resumen
Este estudio revela la estructura cristalina de bajo pH de los canales iónicos sensibles al ácido (ASIC), detallando cómo la unión de protones a grupos carboxilo desencadena la apertura del canal a través de cambios conformacionales.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Estructural Biología estructural.
- La neurociencia es la neurociencia.
Sus antecedentes:
- Los canales iónicos sensibles al ácido (ASIC) son receptores activados por protones involucrados en el dolor, el accidente cerebrovascular y la memoria.
- Los ASIC pertenecen a la familia de los canales de sodio epitelial/degenerina.
Objetivo del estudio:
- Para determinar la estructura cristalina de bajo pH de un pollo mutante de deleción ASIC1.
- Para dilucidar el mecanismo de activación de protones en ASICs.
Principales métodos:
- Cristalografía de rayos X con una resolución de 1.9 A.
- Estudios electrofisiológicos con el uso de mutantes de aspartato a asparagina.
Principales resultados:
- La estructura homotrimérica en forma de cáliz revela características clave que incluyen hélices transmembrana y un dominio extracelular rico en disulfuro.
- Los residuos ácidos y los pares carboxilo-carboxilato en el dominio extracelular son cruciales para la detección de protones.
- Un dominio "pulgar" enlaza la unión de protones con la apertura del canal iónico, lo que demuestra cambios conformacionales de largo alcance.
Conclusiones:
- La estructura proporciona una base molecular detallada para la activación de protones ASIC.
- La detección de protones implica grupos carboxilatos específicos y cambios de conformación transmitidos al poro del canal iónico.
Videos de Conceptos Relacionados
04:02Weak Acid Solutions
Few compounds act as strong acids. A far greater number of compounds behave as weak acids and only partially react with water, leaving a large majority of dissolved molecules in their original form and generating a relatively small amount of hydronium ions. Weak acids are commonly encountered in nature, being the substances partly responsible for the tangy taste of citrus fruits, the stinging sensation of insect bites, and the unpleasant smells associated with body odor. A familiar example of a...
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...
03:05Acid Strength and Molecular Structure
Binary Acids and Bases
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...