Effect of linolenic acid on release of the 43 kDa polypeptide and manganese from photosystem II membranes depleted of the 33 kDa extrinsic polypeptide

1991 ◽  
Vol 82 (2) ◽  
pp. 271-277
Author(s):  
Maciej Garstka ◽  
Zbigniew Kaniuga
Keyword(s):  
Photosystem Ii ◽  
Linolenic Acid

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

Involvement of protein phosphorylation in the sensitivity of photosystem II to strong illumination

1994 ◽  
Vol 92 (1) ◽  
pp. 181-187
Author(s):  
Maria T. Giardi ◽  
Josef Komenda ◽  
Jiri Masojidek
Keyword(s):  
Photosystem Ii ◽  
Protein Phosphorylation

Dihomo-γ-Linolenic Acid in Patients with Atherosclerosis: Effects on Platelet Aggregation, Plasma Lipids and Low-Density Lipoprotein-Induced Inhibition of Prostacyclin Generation

1984 ◽  
Vol 51 (02) ◽  
pp. 186-188 ◽  
Author(s):  
A Szczeklik ◽  
R J Gryglewski ◽  
K Sladek ◽  
E Kostka-Trąbka ◽  
A Żmuda
Keyword(s):  
Linolenic Acid ◽  
Plasma Lipids ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Thromboxane A2 ◽  
Low Density ◽  
Red Cell ◽  
Double Blind ◽  
Daily Dose ◽  
Antithrombotic Effects

SummaryDihomo-γ-linolenic acid (DHLA), a precursor of monoenoic anti-aggregatory prostaglandins (PGE1, PGD2), was administered for 4 weeks in a daily dose of 1.0 g into 33 patients with atherosclerosis on a basis of a double-blind trial. Comparison of treatment and placebo groups revealed elevation of DHLA in red cell lipids in DHLA-treated subjects. No differences, however, between the two groups could be observed in platelet aggregability, thromboxane A2 generation by platelets, serum cholesterol, PGE1 and PGE2 levels, and in inhibitory activity of low-density lipoproteins against prostacyclin synthetizing system in arteries. The dietary supplementation used did not lead to distinct antithrombotic effects.

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