title: Extra proton translocation and membrane potential generation--universal properties of cytochrome bc1/b6f complexes reconstituted into liposomes.
abstract: Isolated cytochrome complexes from different sources like beef heart mitochondria, spinach chloroplasts, cyanobacteria, and photosynthetic bacteria were incorporated into liposomes by sonication as revealed by sucrose density gradient centrifugation and electron microscopy. The reconstituted cytochrome complexes show suppressed rates of quinol-cytochrome c/plastocyanin oxidoreduction which can be stimulated by ionophores and uncouplers. In addition, extra proton translocation out of the vesicles and membrane potential generation during electron transport were observed, suggesting a universal mechanism of electron and proton transport through all the tested cytochrome complexes.
mesh_terms: D000818:Animals; D002417:Cattle; D002736:Chloroplasts / Q000201:enzymology*; D000458:Cyanobacteria / Q000201:enzymology*; D003580:Cytochromes / Q000378:metabolism*; D045348:Cytochromes f; D014450:Electron Transport Complex III; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008081:Liposomes; D046911:Macromolecular Substances; D008564:Membrane Potentials; D008929:Mitochondria, Heart / Q000201:enzymology*; D009097:Multienzyme Complexes / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D010944:Plants / Q000201:enzymology; D011808:Quinone Reductases / Q000378:metabolism*; D012242:Rhodobacter sphaeroides / Q000201:enzymology*; D013045:Species Specificity
chemical_list: D003580:Cytochromes; D008081:Liposomes; D046911:Macromolecular Substances; D009097:Multienzyme Complexes; D045348:Cytochromes f; D009247:NADH, NADPH Oxidoreductases; D011808:Quinone Reductases; D014450:Electron Transport Complex III