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Reducción de nitrito mediada por modelos de hemo. Rutas hacia NO y HNO?
Julie L Heinecke1, Chosu Khin, Jose Clayston Melo Pereira
1Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California 93106-9510, USA.
Journal of the American Chemical Society
|February 21, 2013
Resumen
Un modelo de ferrihemo soluble en agua facilita la transferencia de oxígeno del nitrito a varias moléculas. Este proceso regenera las especies activas de hierro y forma óxido nítrico (NO) y nitroxilo (HNO), relevantes para el nitrito.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Química Medicinal La Química Medicinal es el campo de la Química Medicinal.
Sus antecedentes:
- El nitrito inorgánico juega un papel protector en las lesiones de isquemia/reperfusión (I/R).
- La formación de óxido nítrico (NO) es un mecanismo clave que subyace a los efectos protectores del nitrito.
- Comprender la química redox del nitrito es crucial para las aplicaciones terapéuticas.
Objetivo del estudio:
- Para investigar los mecanismos de transferencia de átomos de oxígeno de un modelo de ferrihemo soluble en agua.
- Para dilucidar las vías de formación de NO y nitroxilo (HNO) a partir de nitrito.
- Explorar la relevancia de estas transformaciones redox para las funciones protectoras del nitrito en la lesión I/R.
Principales métodos:
- Se utilizó un modelo de ferrihemo soluble en agua, Fe (III) (TPPS).
- Reacciones estudiadas con varios reductores incluyendo fosfinas y tiolos biológicos (cisteína, glutatión).
- Empleó sensores electroquímicos y experimentos de captura para identificar intermedios reactivos.
Principales resultados:
- La transferencia de átomos de oxígeno mediada por Fe (III) (TPPS) desde el nitrito a las fosfinas y los tiolos.
- Los ácidos sulfénicos se formaron a partir de tiolos, pero reaccionaron rápidamente con el exceso de tiol.
- Las transformaciones redox condujeron a la regeneración de Fe (III) (TPPS) y la formación de N2O, NO y HNO.
Conclusiones:
- El modelo de ferrihema facilita la transferencia de átomos de oxígeno derivados del nitrito y el ciclo redox.
- El HNO se identifica como un intermediario clave en la formación de N2O.
- Los mecanismos estudiados proporcionan información sobre los efectos protectores del nitrito durante las lesiones I/R.
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