title: PRoperties of the low-temperature photosystem I primary reaction in the P-700-chlorophyll alpha-protein.
abstract: The Photosystem I primary reaction, as measured by electron paramagnetic resonance changes of P-700 and a bound iron-sulfur center, has been studied at 15 degrees K in P-700-chlorophyll alpha-protein complexes isolated from a blue-green alga. One complex, prepared with sodium dodecyl sulfate shows P-700 photooxidation only at 300 degrees K, whereas a second complex, prepared with Triton X-100, is photochemically active at 15 degrees K as well as at 300 degrees K. Analysis of these two preparations shows that the absence of low-temperature photoactivity in the sodium dodecyl sulfate complex reflects a lack of bound iron-sulfur centers in this preparation and supports the assignment of an iron-sulfur center as the primary electron acceptor of Photosystem I.
mesh_terms: D001665:Binding Sites; D002734:Chlorophyll / Q000378:metabolism*; D000458:Cyanobacteria / Q000378:metabolism*; D003580:Cytochromes / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D007501:Iron / Q000032:analysis; D046911:Macromolecular Substances; D008667:Metalloproteins / Q000378:metabolism; D010788:Photosynthesis; D010940:Plant Proteins / Q000378:metabolism*; D011092:Polyethylene Glycols; D011485:Protein Binding; D013455:Sulfur / Q000032:analysis; D013696:Temperature
chemical_list: D003580:Cytochromes; D046911:Macromolecular Substances; D008667:Metalloproteins; D010940:Plant Proteins; D002734:Chlorophyll; D011092:Polyethylene Glycols; D013455:Sulfur; D007501:Iron