Oxidative modifications of the Photosystem II D1 protein by reactive oxygen species: from isolated protein to cyanobacterial cells
Language English Country United States Media print
Document type Journal Article, Research Support, Non-U.S. Gov't
- MeSH
- Photosystem II Protein Complex analysis chemistry MeSH
- Heme chemistry metabolism MeSH
- Ligands MeSH
- Molecular Sequence Data MeSH
- Mutation MeSH
- Oxidation-Reduction MeSH
- Peptide Fragments chemistry metabolism MeSH
- Hydrogen Peroxide pharmacology MeSH
- Reactive Oxygen Species antagonists & inhibitors pharmacology MeSH
- Protein Folding MeSH
- Amino Acid Sequence MeSH
- Cyanobacteria chemistry drug effects genetics MeSH
- Superoxides pharmacology MeSH
- Light MeSH
- Thylakoids chemistry drug effects radiation effects MeSH
- Iron chemistry metabolism MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Photosystem II Protein Complex MeSH
- Heme MeSH
- Ligands MeSH
- Peptide Fragments MeSH
- Hydrogen Peroxide MeSH
- Reactive Oxygen Species MeSH
- Superoxides MeSH
- Iron MeSH
Action of reactive oxygen species (ROS) on the isolated D1 protein, a key component of Photosystem II (PSII) complex, was studied and compared with the effect of high irradiance on this protein in mildly solubilized photosynthetic membranes and cells of the cyanobacterium Synechocystis. Whereas singlet oxygen caused mainly protein modification reflected by shift of its electrophoretic mobility, action of hydrogen peroxide and superoxide resulted in generation of specific fragments. Hydroxyl radicals as the most ROS induced fast disappearance of the protein. The results substantiate the ability of ROS to cause direct scission of the D1 peptide bonds. Similar D1 modification, fragmentation and additionally cross-linking with other PSII subunits were observed during illumination or hydrogen peroxide treatment of mildly solubilized thylakoids. Peroxide-induced fragmentation did not occur in thylakoids of the strain lacking a ligand to the nonheme iron, confirming the role of this prosthetic group in the D1-specific cleavage. The D1 modification, fragmentation and cross-linking were suppressed by ROS scavengers, supporting the direct role of ROS in these phenomena. Identical symptoms of the ROS-induced D1 damage were detected in illuminated cells of Synechocystis mutants with a higher probability of ROS formation, documenting the relevance of the in vitro results for the situation in vivo.
References provided by Crossref.org
Tocopherol controls D1 amino acid oxidation by oxygen radicals in Photosystem II
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