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Start Over Creator Garab, G. Format bez média Harvested from CDK

2. Alternative cyanide-sensitive oxidase interacting with photosynthesis in synechocystis PCC6803. Ancestor of the terminal oxidase of chlororespiration?

Creator:
Büchel, C., Zsíros, O., and Garab, G.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
absorbance, azide, cyanobacteria, cytochromes, flash radiation, KCN, NaN3, phylogeny, respiration, and salicyl hydroxamic acid
Language:
Multiple languages
Description:
Influence of respiration on photosynthesis in Synechocystis PCC6803 was studied by measuring the redox transients of cytochrome f (cyt f) upon excitation of the cells with repetitive single turnover flashes. Upon the addition of KCN the flash-induced oxidation of cyt f was increased and the rereduction of cyt f+ was accelerated. Dependence of these effects on the concentration of KCN clearly demonstrated the existence of two cyanide-sensitive oxidases interacting with photosynthesis: cyt aa3, which was sensitive to low concentrations of cyanide, and an alternative oxidase, which could be suppressed by using ≥1 mM KCN. The interaction between the photosynthetic and the respiratory electron transport chains was regulated mainly by the activity of the alternative cyanide-sensitive oxidase. The oxidative pathway involving the alternative cyanide-sensitive oxidase was insensitive to salicyl hydroxamic acid and azide. The close resemblance of the inhibition pattern reported here and that described for chlororespiration in algae and higher plants strongly suggest that an oxidase of the same type as the alternative cyanide-sensitive oxidase of cyanobacteria functions as a terminal oxidase in chloroplasts. and C. Büchel, O. Zsíros, G. Garab.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Effect of chromium on photosystem 2 in the unicellular green alga, Chlorella pyrenoidosa

Creator:
Hörcsik, Z. T., Kovács, L., Láposi, R., Mészáros, I., Lakatos, G., and Garab, G.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, D1 protein, Western blot analysis, and thermoluminescence
Language:
Multiple languages
Description:
We investigated the effect of chromium (20-40 g m-3, 8-72 h) on the photosystem 2 (PS2) activities of Chlorella pyrenoidosa cells. By using chlorophyll fluorescence transients, thermoluminescence, oxygen polarography, and Western blot analysis for D1 protein we found that inhibition of PS2 can be accounted for by the enhanced photodestruction of the reaction centres in the cells cultivated in the presence of Cr(VI) at 25 °C in "white light" (18 W m-2). Hence photodestruction of D1 is caused by an enhanced oxidative stress and lipid peroxidation, as indicated by the appearance of a high-temperature thermoluminescence band. and Z. T. Hörcsik ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Increased thermal stability of photosystem II and the macro-organization of thylakoid membranes, induced by co-solutes, associated with changes in the lipid-phase behaviour of thylakoid membranes

Creator:
Kotakis, C., Akhtar, P., Zsiros, O., Garab, G., and Lambrev, P. H.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, circular dichroism, merocyanine-540, non-bilayer lipids, osmolyte, time-resolved fluorescence spectroscopy, 2, and 581
Language:
Multiple languages
Description:
The principal function of the thylakoid membrane depends on the integrity of the lipid bilayer, yet almost half of the thylakoid lipids are of non-bilayer-forming type, whose exact functions are not fully understood. Non-bilayer lipids can be extruded from the membrane in the presence of high concentrations of co-solutes. We applied 2 M sucrose to induce lipid phase separation in isolated thylakoid membranes, following consequent structural and physiological effects. Circular dichroism spectroscopy indicated significant changes in the chiral macro-arrangement of the pigment-protein complexes, which were reversed after washing out the co-solute. Similarly, merocyanine-540 fluorescence suggested reversible changes in the lipid phases. The PSII function, as tested by chlorophyll fluorescence induction transients and time-resolved fluorescence, was almost unaffected. However, the presence of sucrose dramatically increased the PSII thermostability, which can partly be explained by a direct osmolyte effect and partly by the lipid phase separation stabilizing the stacked membrane., C. Kotakis, P. Akhtar, O. Zsiros, G. Garab, P. H. Lambrev., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public