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Captación y oxidación de hierro por la ferritina moduladas dinámicamente por la arquitectura del fosfato de
Anitha Rajendran1, Sean Henley1, Brent Nannenga2
1Department of Chemistry, State University of New York, Potsdam, NY, USA.
International journal of biological macromolecules
|February 28, 2026
Resumen
Ferritina
Área de la Ciencia:
- Bioquímica y Biología Molecular
- Metabolismo Celular del Hierro
- Interacciones Proteína-Ligando
Sus antecedentes:
- La ferritina es crucial para el almacenamiento celular de hierro y la prevención del estrés oxidativo.
- No se comprende completamente el mecanismo por el cual la estructura de la ferritina detecta y responde al entorno químico celular.
- Comprender la capacidad de respuesta ambiental de la ferritina es clave para descifrar la homeostasis del hierro celular.
Objetivo del estudio:
- Elucidar cómo la arquitectura macromolecular de la ferritina permite la respuesta al entorno químico celular.
- Investigar el mecanismo de compuerta electrostática de la actividad de oxidación del hierro de la ferritina.
- Determinar la influencia de los metabolitos intracelulares en el manejo del hierro por la ferritina.
Principales métodos:
- Criomicroscopía electrónica (crio-EM) de alta resolución para visualizar cambios estructurales.
- Mediciones de fluorescencia y calorimétricas para evaluar la unión de nucleótidos.
- Ensayos in vitro utilizando ferritina purificada y lisados celulares en condiciones variables.
Principales resultados:
- La actividad de oxidación del hierro de la ferritina está modulada por interacciones electrostáticas en sus canales de 3 pliegues, sensible a la carga de la solución.
- Los nucleótidos trifosfato atenuan significativamente la oxidación de Fe2+ catalizada por la ferritina, con efectos más débiles de los difosfatos y monofosfatos.
- La crio-EM reveló cambios dependientes de las condiciones en la densidad no proteica, lo que indica interacciones dinámicas de solvente/iones en lugar de la unión discreta de ligandos.
Conclusiones:
- La ferritina posee un mecanismo intrínseco de compuerta electrostática que regula dinámicamente la oxidación del hierro.
- Este mecanismo permite a la ferritina modular reversiblemente la captación de hierro en respuesta al entorno químico celular, particularmente a las concentraciones de nucleótidos.
- Los hallazgos resaltan la adaptabilidad de la ferritina en el manejo de la homeostasis del hierro en diversas condiciones celulares y organismos.
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