The effects of ultraviolet irradiation on P680+ reduction in PS II core complexes measured for individual S-states and during repetitive cycling of the oxygen-evolving complex

1996 ◽  
Vol 49 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Adele Post ◽  
P. B. Lukins ◽  
P. J. Walker ◽  
A. W. D. Larkum
Keyword(s):  
Ultraviolet Irradiation ◽  
Oxygen Evolving Complex ◽  
Ps Ii ◽  
Oxygen Evolving ◽  
S States ◽  
Ps Ii Core Complexes ◽  
Ps Ii Core

scholarly journals Physiologically active chloroplasts contain pools of unassembled extrinsic proteins of the photosynthetic oxygen-evolving enzyme complex in the thylakoid lumen.

1991 ◽  
Vol 115 (2) ◽  
pp. 321-328 ◽  
Author(s):  
W F Ettinger ◽  
S M Theg
Keyword(s):  
Oxygen Evolving Complex ◽  
Ps Ii ◽  
Thylakoid Lumen ◽  
Core Proteins ◽  
Before And After ◽  
Detergent Treatment ◽  
Extrinsic Proteins ◽  
Oxygen Evolving ◽  
Triton X ◽  
Ps Ii Core

The oxygen-evolving complex (OEC) of photosystem II (PS II) consists of at least three extrinsic membrane-associated protein subunits, OE33, OE23, and OE17, with associated Mn2+, Ca2+, and Cl- ions. These subunits are bound to the lumen side of PS II core proteins embedded in the thylakoid membrane. Our experiments reveal that a significant fraction of each subunit is normally present in unassembled pools within the thylakoid lumen. This conclusion was supported by immunological detection of free subunits after freshly isolated pea thylakoids were fractionated with low levels of Triton X-100. Plastocyanin, a soluble lumen protein, was completely released from the lumen by 0.04% Triton X-100. This gentle detergent treatment also caused the release from the thylakoids of between 10 and 20%, 40 and 60%, and 15 and 50% of OE33, OE23, and OE17, respectively. Measurements of the rates of oxygen evolution from Triton-treated thylakoids, both in the presence and absence of Ca2+, and before and after incubation with hydroquinone, demonstrated that the OEC was not dissociated by the detergent treatment. Thylakoids isolated from spinach released similar amounts of extrinsic proteins after Triton treatment. These data demonstrate that physiologically active chloroplasts contain significant pools of unassembled extrinsic OEC polypeptide subunits free in the lumen of the thylakoids.

Photoinactivation of Photosynthetic Electron Transport under Anaerobic and Aerobic Conditions in Isolated Thylakoids of Spinach

1992 ◽  
Vol 47 (1-2) ◽  
pp. 63-68 ◽  
Author(s):  
Rekha Chaturvedi ◽  
M. Singh ◽  
P. V. Sane
Keyword(s):  
Electron Transport ◽  
Photosynthetic Electron Transport ◽  
Oxygen Evolving Complex ◽  
Reaction Centre ◽  
Ps Ii ◽  
Ps I ◽  
S2 State ◽  
The Stability ◽  
Oxygen Evolving ◽  
Spinach Thylakoids

Abstract The effect of exposure to strong white light on photosynthetic electron transport reactions of PS I and PS II were investigated in spinach thylakoids in the absence or presence of oxygen. Irrespective of the conditions used for photoinactivation, the damage to PS II was always much more than to PS I. Photoinactivation was severe under anaerobic conditions compared to that in air for the same duration. This shows that the presence of oxygen is required for prevention of photoinactivation of thylakoids. The susceptibility of water-splitting complex in photoinactivation is indicated by our data from experiments with chloride-deficient chloroplast membranes wherein it was observed that the whole chain electron transport from DPC to MV was much less photoinhibited than that from water. The data from the photoinactivation experiments with the Tris-treated thylakoids indicate another photodam age site at or near reaction centre of PS II. DCMU-protected PS II and oxygen-evolving complex from photoinactivation. DCMU protection can also be interpreted in terms of the stability of the PS II complex when it is in S2 state.

Reconstitution of the Endogenous Plastoquinone Pool in Photosystem II (PS II) Membrane Fragments, Inside-Out-Vesicles, and PS II Core Complexes from Spinach

Biochemistry ◽  
1995 ◽  
Vol 34 (48) ◽  
pp. 15721-15731 ◽  
Author(s):  
J. Kurreck ◽  
A. G. Seeliger ◽  
F. Reifarth ◽  
M. Karge ◽  
G. Renger
Keyword(s):  
Photosystem Ii ◽  
Ps Ii ◽  
Plastoquinone Pool ◽  
Inside Out ◽  
Ps Ii Core Complexes ◽  
Ps Ii Core

Effects of hydrogen/deuterium exchange on photosynthetic water cleavage in PS II core complexes from spinach

FEBS Letters ◽  
1996 ◽  
Vol 378 (2) ◽  
pp. 140-144 ◽  
Author(s):  
M. Karge ◽  
K.-D. Irrgang ◽  
S. Sellin ◽  
R. Feinäugle ◽  
B. Liu ◽  
...  
Keyword(s):  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Ps Ii ◽  
Hydrogen Deuterium ◽  
Water Cleavage ◽  
Ps Ii Core Complexes ◽  
Ps Ii Core

Surface structure of the photosystem II complex

1991 ◽  
Vol 49 ◽  
pp. 196-197
Author(s):  
Kenneth R. Miller ◽  
Jules S. Jacob
Keyword(s):  
Photosystem Ii ◽  
Photosynthetic Reaction Center ◽  
Oxygen Evolving Complex ◽  
Photosynthetic Membrane ◽  
Ps Ii ◽  
Quick Freezing ◽  
Inner Surface ◽  
Oxygen Evolving ◽  
Excellent Source ◽  
Photosynthetic Mutant

The Photosystem II (PS-II) complex is organized around a photosynthetic reaction center (RC) embedded in the photosynthetic membrane. PS-II traps the energy of sunlight and uses it drive highenergy electron transport across the photosynthetic membrane. PS-II is closely associated with a group of proteins known as the oxygen-evolving complex (OEC), which are bound to the inner surface of the photosynthetic membrane. This complex splits water to yield electrons that are passed to the RC, releasing molecular oxygen. We have used freeze-etch electron microscopy to study 2-dimensional crystals of the PS-II complex obtained from a photosynthetic mutant of barley (viridiszb63) kindly provided by Dr. David Simpson of the Carlsberg Institute of Copenhagen (Simpson & von Wettstein, 1980). The photosynthetic membranes of these mutant plants lack photosystem I, and consequently contain extensive crystalline membrane regions enriched in PS-II. These plants are an excellent source of PS-II sheetlike crystals, obtainable without the use of detergents or chemical modification: Figure 1, prepared by quick-freezing, deep-etching, and rotary shadowing, illustrates the appearance of these sheetlike crystals.

Surface Charge Density Changes in Isolated Photosystem II Membranes Induced by Depletion of the Extrinsic Polypeptides of the Oxygen Evolving System

1990 ◽  
Vol 45 (6) ◽  
pp. 627-632 ◽  
Author(s):  
Alexander G. Ivanov ◽  
Mira C. Busheva ◽  
Maya Y. Velitchkova
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Oxygen Evolving Complex ◽  
Partial Recovery ◽  
Ps Ii ◽  
Extrinsic Polypeptides ◽  
Evolving System ◽  
Oxygen Evolving System ◽  
Oxygen Evolving

Abstract Treatment of PS II particles with either 1 M NaCl or alkaline Tris (1 M , pH 8.4) caused a considerable decrease in the average net negative surface charge density, concomitant with depletion of the extrinsic 17, 24 and 33 kDa proteins of the oxygen evolving complex from the membranes. The partial recovery of the values for surface charge in both NaCl- and Tris-treated membranes was registered after reconstitution experiments with the three proteins. These results are compared with the data for the charge densities of the thylakoid membranes, to examine the role of the three extrinsic proteins in the formation of heterogeneous arrangement of surface charge across the appressed (granal) thylakoids.

Effect of Tobamovirus Infection on Thermoluminescence Characteristics of Chloroplasts from Infected Plants

1999 ◽  
Vol 54 (9-10) ◽  
pp. 634-639 ◽  
Author(s):  
Jaber Rahoutei ◽  
Matilde Barón ◽  
Isabel García-Luque ◽  
Magdolna Droppa ◽  
Neményi ◽  
...  
Keyword(s):  
Nicotiana Benthamiana ◽  
Peak Position ◽  
Oxygen Evolving Complex ◽  
Transport Activity ◽  
Concomitant Increase ◽  
Oxidative Breakdown ◽  
Electron Transport Activity ◽  
Oxygen Evolving ◽  
Splitting System ◽  
S States

Changes of thermoluminescence characteristics as well as the O2-evolving capacity was analysed in chloroplasts isolated from Nicotiana benthamiana infected with pepper and paprika mild mottle viruses and their chimeric hybrids. The electron transport activity in thylakoids of virus-infected plants was inhibited and could be restored by adding DPC or Ca2+ which indicated that the virus infection altered the oxygen-evolving complex. In thermoluminescence characteristics of plants infected with either viruses, the first well defined response was a shift in the peak position of the B band from 20 °C to 35 °C corresponding to S3(S2)QB- and S2QB- charge recombinations, respectively, which showed an inhibition in the formation of higher S states in the water splitting system. Simultaneously, a new band appeared around 70 °C due to chemiluminescence of lipid peroxidation. Further progress of the viral infection dramatically decreased the intensity of bands originated from charge recombinations with a concomitant increase of the band at 70 °C indicating the general oxidative breakdown of injured thylakoids

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