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Updated: Feb 8, 2026

Visualizing the Conformational Dynamics of Membrane Receptors Using Single-Molecule FRET

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Visualización directa de la dinámica de conformación de los trimadores de hemaglutinina de la gripe

Dibyendu Kumar Das¹, Ramesh Govindan¹, Ivana Nikić-Spiegel²

¹Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, MA 02111, USA.

|July 3, 2018

Resumen

La hemaglutinina de la gripe (HA) sufre cambios conformacionales dinámicos y reversibles, no un solo paso irreversible, durante la fusión de la membrana viral. Este proceso dinámico, visualizado por smFRET, asegura que la fusión ocurra solo con la interacción de la membrana objetivo.

Área de la Ciencia:

Virología
La biofísica
Biología molecular

Sus antecedentes:

La hemaglutinina de la gripe (HA) media la entrada del virus a través de la fusión de la membrana.
El cambio conformacional de la subunidad HA2 es clave para la fusión.
Los modelos actuales muestran el HA2 como estático e irreversiblemente reorganizado a pH ácido.

Objetivo del estudio:

Para visualizar directamente los cambios conformacionales desencadenados por el pH de los trimadores de HA.
Para aclarar la naturaleza dinámica de HA2 durante la fusión de la membrana.
Desafiar el modelo estático de la fusión mediada por HA.

Principales métodos:

Imágenes de transferencia de energía de resonancia de Förster de una sola molécula (smFRET).
Visualización de los trímeres de HA en la superficie viral.
Análisis de la dinámica conformacional dependiente del pH.

Principales resultados:

HA2 exhibe un intercambio reversible entre los estados previos a la fusión y los estados intermedios.
La acidificación y la unión al receptor cambian el equilibrio de HA2 hacia la fusión.
La interacción con la membrana objetivo induce una transición irreversible al estado posterior a la fusión.

Conclusiones:

La fusión de membranas mediada por HA es un proceso dinámico de múltiples pasos.
Las conformaciones reversibles de HA2 previenen la fusión prematura.
Este mecanismo dinámico asegura la entrada eficiente del virus en el sitio objetivo.

Palabras clave:

Fusión por membrana Dinámica de las proteínas fluorescencia de una sola molécula En el caso de los Entrada del virus

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