PICOREL CASTAÑO , Rafael

The light-induced difference absorption spectra associated to the photo-accumulation of reduced pheophytin a were studied in the isolated D1–D2–Cyt b559 complex in the presence of variable methyl viologen concentrations and different illumination conditions under anaerobiosis. Depending on the methyl viologen/reaction centre ratio, the relative...

Toxic Cu (II) effect on cytochrome b559 under aerobic photoinhibitory conditions was examined in two different photosystem II (PSII) membrane preparations active in oxygen evolution. The preparations differ in the content of cytochrome b559 redox potential forms. Difference absorption spectra showed that the presence of Cu (II) induced the...

Anomalies in photosynthetic activity of the soybean cell line STR7, carrying a single mutation (S268P) in the chloroplastic gene psbA that codes for the D1 protein of the photosystem II, have been examined using different spectroscopic techniques. Thermoluminescence emission experiments have shown important differences between STR7 mutant and...

The cytochrome b559 is a heme-bridged heterodimeric protein with two subunits, α and β. Both subunits from Synechocystis sp. PCC 6803 have previously been cloned and overexpressed in Escherichia coli and in vivo reconstitution experiments have been carried out. The formation of homodimers in the bacterial membrane with endogenous heme was only...

A study of the in vitro reconstitution of sugar beet cytochrome b 559 of the photosystem II is described. Both α and β cytochrome subunits were first cloned and expressed in Escherichia coli. In vitro reconstitution of this cytochrome was carried out with partially purified recombinant subunits from inclusion bodies. Reconstitution with...

Detergent effect on Cytochrome b559 from spinach photosystem II was studied by electron paramagnetic resonance (EPR) spectroscopy in D1-D2-Cyt b559 complex preparations. Various n-dodecyl-β-D-maltoside concentrations from 0 to 0.2% (w/v) were used to stabilise the D1-D2-Cyt b559 complexes. Low spin heme ...