English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/8231
Compartir / Impacto:
Add this article to your Mendeley library MendeleyBASE
Citado 17 veces en Web of Knowledge®  |  Ver citas en Google académico
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar otros formatos: Exportar EndNote (RIS)Exportar bibText (RIS)Exportar csv (RIS)

Alterations in Photosystem II electron transport as revealed by thermoluminescence of Cu-poisoned chloroplasts

Autor Horváth, Gábor; Arellano, Juan B. ; Droppa, Magdolna; Barón Ayala, Matilde
Palabras clave Copper
Electron transfer
Photosystem II
Tyrosine Z
Fecha de publicación ago-1998
Citación Photosynthesis Research 57(2): 175-182 (1998)
ResumenThe thermoluminescence characteristics of functionally intact thylakoids and TRIS-washed BBY particles were studied under Cu(II) poisoned conditions. In thylakoids, both the A and B thermoluminescence bands corresponding to S3QA- and S2S3QB- charge recombinations, respectively showed specific responses to Cu(II) treatment. The amplitude of the B band was gradually decreased, which corresponds to the Cu(II) induced inactivation of TyrZ. The simultaneous stepwise shift in the peak position of the B band indicated, however, that S3QB- charge recombination is more resistant to Cu(II) poisoned conditions. The shifted peak position of the A band toward the higher temperature in Cu(II) treated thylakoids also showed a change in the redox span between the recombination partners generating the A band of the glow curve. The AT band due to the His+QA- recombination in TRIS-washed BBY particles was insensitive to Cu(II) addition indicating that Cu(II) did not affect either His+ or QA-. The unaffected intensity of the A and AT bands when Cu(II) inhibits TyrZ function favours the assumption of an alternative pathway in which functional TyrZ is not required. In addition, Cu-induced changes of the TL bands were compared to those produced by the Tyr and His modifiers NBD and DEPC, respectively. We obtained very similar results regarding TL bands by either adding NBD or Cu-poisoning in functional thylakoids. Regarding DEPC, the A and AT bands were abolished by increasing concentrations of the His modifier. This effect was associated with the decrease of the B band and its replacement by the Q band at around 0°C. Comparing our data obtained by Cu, NBD and DEPC treatments, we have found a strong interrelation between His+ and S3 state. We assume that in some inhibitory conditions in the S3 state His is oxidized in place of Mn and this alternative pathway does not require functional TyrZ.
Descripción 7 pages, 6 figures.
Versión del editorhttp://dx.doi.org/10.1023/A:1006051815176
URI http://hdl.handle.net/10261/8231
ISSN0166-8595 (Print)
1573-5079 (Online)
Aparece en las colecciones: (IRNASA) Artículos
(EEZ) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
Horvath et al 1998Digital CSIC.pdf222,11 kBAdobe PDFVista previa
Mostrar el registro completo

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.