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Estructura y función en las piscidinas antimicrobianas: posición de la histidina, direccionalidad de la inserción de

Mihaela Mihailescu¹, Mirco Sorci², Jolita Seckute³

¹Institute for Bioscience and Biotechnology Research , University of Maryland , Rockville , Maryland 20850 , United States.

Journal of the American Chemical Society

|May 31, 2019

Resumen

Las piscidinas p1 y p3 muestran distintas interacciones en la membrana debido al contenido de histidina. Piscidina p1 y sus derivados

Área de la Ciencia:

La biofísica
La bioquímica
Biología de las membranas

Sus antecedentes:

Las piscidinas son péptidos antimicrobianos ricos en histidina.
Muestran estructuras anfipáticas alfa-hélices.
Su actividad de pH sugiere potencial biomédico.

Objetivo del estudio:

Investigar cómo las variaciones de histidina influyen en la permeabilización de la piscidina.
Comparar la interacción en la membrana de la piscidina p1 y p3.
Elucidar la actividad dependiente del pH y la inserción en la membrana.

Principales métodos:

Difracción de neutrones
Ensayos de fugas de tintes
Titraciones controladas por RMN
Simulaciones de dinámica molecular
Espectroscopia de impedancia electroquímica

Principales resultados:

La permeabilización de la piscidina p3 es sensible al pH, a diferencia de la p1.
La piscidina p1 exhibe una inserción en la membrana más profunda y una mayor disrupción de la membrana.
El contenido de histidina y la anfipaticidad dictan la direccionalidad de la inserción y la resistencia al pH.

Conclusiones:

Las variaciones de histidina en las piscidinas conducen a la permeabilización diferencial de la membrana.
La histidina (H17) única de la piscidina p1 confiere una inserción en la membrana más profunda y resistente al pH.
Se proporcionan conocimientos mecánicos sobre las interacciones péptido-membrana de los antimicrobianos.

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