scholarly journals Characterization of the Free and Membrane-Associated Fractions of the Thylakoid Lumen Proteome in Arabidopsis thaliana

2021 ◽  
Vol 22 (15) ◽  
pp. 8126
Author(s):  
Peter J. Gollan ◽  
Andrea Trotta ◽  
Azfar A. Bajwa ◽  
Ilaria Mancini ◽  
Eva-Mari Aro
Keyword(s):  
Arabidopsis Thaliana ◽  
Photosynthetic Electron Transport ◽  
Oxygen Evolving Complex ◽  
Ps Ii ◽  
Post Translational Modifications ◽  
Thylakoid Lumen ◽  
Novel Proteins ◽  
The Difference ◽  
Oxygen Evolving

The thylakoid lumen houses proteins that are vital for photosynthetic electron transport, including water-splitting at photosystem (PS) II and shuttling of electrons from cytochrome b6f to PSI. Other lumen proteins maintain photosynthetic activity through biogenesis and turnover of PSII complexes. Although all lumen proteins are soluble, these known details have highlighted interactions of some lumen proteins with thylakoid membranes or thylakoid-intrinsic proteins. Meanwhile, the functional details of most lumen proteins, as well as their distribution between the soluble and membrane-associated lumen fractions, remain unknown. The current study isolated the soluble free lumen (FL) and membrane-associated lumen (MAL) fractions from Arabidopsis thaliana, and used gel- and mass spectrometry-based proteomics methods to analyze the contents of each proteome. These results identified 60 lumenal proteins, and clearly distinguished the difference between the FL and MAL proteomes. The most abundant proteins in the FL fraction were involved in PSII assembly and repair, while the MAL proteome was enriched in proteins that support the oxygen-evolving complex (OEC). Novel proteins, including a new PsbP domain-containing isoform, as well as several novel post-translational modifications and N-termini, are reported, and bi-dimensional separation of the lumen proteome identified several protein oligomers in the thylakoid lumen.

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.

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.

scholarly journals Manganese–calcium clusters supported by calixarenes

2015 ◽  
Vol 44 (5) ◽  
pp. 2132-2137 ◽  
Author(s):  
Rebecca O. Fuller ◽  
George A. Koutsantonis ◽  
Ivan Lozić ◽  
Mark I. Ogden ◽  
Brian W. Skelton
Keyword(s):  
Photosystem Ii ◽  
Structural Characterization ◽  
Oxygen Evolving Complex ◽  
Oxygen Evolving ◽  
Calixarene Ligand

An investigation inspired by the structure of the oxygen-evolving complex of photosystem II has resulted in the isolation and structural characterization of the first examples of Mn/Ca clusters supported by a calixarene ligand.

Structural characterization of the manganese sites in the photosynthetic oxygen-evolving complex using x-ray absorption spectroscopy

1990 ◽  
Vol 112 (7) ◽  
pp. 2549-2557 ◽  
Author(s):  
James E. Penner-Hahn ◽  
Richard M. Fronko ◽  
Vincent L. Pecoraro ◽  
Charles F. Yocum ◽  
Scott D. Betts ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Structural Characterization ◽  
Oxygen Evolving Complex ◽  
X Ray ◽  
Photosynthetic Oxygen ◽  
Oxygen Evolving ◽  
X Ray Absorption
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