title: Labeling of chromatophore membranes and reaction centers from the photosynthetic bacterium Rhodospirillum rubrum with the hydrophobic marker 5-[125I]iodonaphthyl-1-azide..
abstract: Chromatophores of the photosynthetic bacterium Rhodospirillum rubrum and isolated reaction centers were labeled with the lipophilic membrane marker 5-[125I]iodonaphthyl-1-azide. The two smaller reaction center proteins L and M bind more label than the larger subunit H, a fact supporting the proposed localisation of the 3 subunits obtained with hydrophilic labels. Besides these integral proteins the lipids, among them mainly the pigments and the quinones, are highly labeled suggesting a hydrophobic environment around these molecules and a preferred reactivity to iodonaphthylazide. Such a hydrophobic environment may be of great importance for the function of the photosynthetic reaction centers especially for the charge separation and the primary reactions in electron transport.
mesh_terms: D001386:Azides; D020130:Bacterial Chromatophores / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003080:Cold Temperature; D006651:Histocytochemistry; D007457:Iodine Radioisotopes; D008563:Membrane Lipids / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D009281:Naphthalenes; D012246:Rhodospirillum / Q000378:metabolism*
chemical_list: D001386:Azides; D007457:Iodine Radioisotopes; D008563:Membrane Lipids; D008565:Membrane Proteins; D009281:Naphthalenes; D002734:Chlorophyll; C015298:iodonaphthylazide