Photoreduction of 2,6-Dichlorophenolindophenol by Diphenylcarbazide: A Photosystem 2 Reaction Catalyzed by Tris-Washed Chloroplasts and Subchloroplast Fragments
AUTOR(ES)
Vernon, Leo P.
RESUMO
The use of diphenylcarbazide as an electron donor coupled to the photoreduction of 2,6-dichlorophenolindophenol by tris-washed chloroplasts or subchloroplast fragments provides a simple and sensitive assay for photosystem 2 of chloroplasts. By varying the concentration of tris buffer at pH 8.0 during an incubation period it is shown that the destruction of oxygen evolution activity is accompanied by a corresponding emergence of an ability to photooxidize diphenylcarbazide, as evidenced by absorbance changes due to diphenylcarbazide at 300 nm. The temperature-sensitive oxidation of diphenylcarbazide is inhibited by DCMU and by high ionic strengths. This activity appears to measure the primary photochemical reaction of photosystem 2.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=396317Documentos Relacionados
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