title: Isolation of a manganese-containing protein complex from photosystem II preparations of spinach.
abstract: Purified 125I-labeled 33-kDa protein binds to calcium-washed photosystem II preparations at high-affinity and low-affinity binding sites. Filling 70% of the high-affinity site with 33-kDa protein induces 63% of the maximum achievable reconstitution of O2-evolving activity. When N-succinimidyl [(4-azidophenyl)dithio]propionate modified 33-kDa protein was reconstituted into Ca(II)-washed membranes under conditions that primarily filled the high-affinity site and then cross-linked to adjacent proteins by illumination of the photoaffinity label, a cross-linked protein complex was formed that could be solubilized from the membranes with sodium dodecyl sulfate. The protein complex consisted of 22-, 24-, 26-, 28-, 29-, and 31-kDa proteins cross-linked to the 33-kDa protein and contained about 3-4 mol of Mn/mol of protein.
mesh_terms: D001386:Azides / Q000494:pharmacology; D002734:Chlorophyll / Q000302:isolation & purification* / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D045342:Light-Harvesting Protein Complexes; D008345:Manganese / Q000032:analysis*; D008970:Molecular Weight; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins / Q000302:isolation & purification* / Q000378:metabolism; D010944:Plants / Q000378:metabolism*
chemical_list: D001386:Azides; D003432:Cross-Linking Reagents; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D002734:Chlorophyll; D008345:Manganese; C033169:3-((4-azidophenyl)dithio)propionic N-hydroxysuccinimide