title: Cytochrome b561 catalyzes transmembrane electron transfer.
abstract: Purified cytochrome b561 from bovine adrenal medulla chromaffin vesicles has been reconstituted into phosphatidylcholine vesicles by a detergent-dialysis method. When the reconstituted cytochrome-containing vesicles were preloaded with ascorbic acid and cytochrome c was added to the external medium, the internal ascorbic acid was able to reduce the external cytochrome c. This reduction of cytochrome c was dependent on the presence of cytochrome b561 in the membrane and was not due to leakage of ascorbate from the vesicles. These results demonstrate that cytochrome b561 catalyzes a transmembrane electron transfer.
mesh_terms: D000313:Adrenal Medulla / Q000378:metabolism; D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D002837:Chromaffin Granules / Q000378:metabolism*; D002838:Chromaffin System / Q000378:metabolism*; D003573:Cytochrome b Group / Q000378:metabolism*; D003574:Cytochrome c Group / Q000378:metabolism; D004579:Electron Transport; D007425:Intracellular Membranes / Q000378:metabolism*; D007700:Kinetics; D010084:Oxidation-Reduction; D014357:Trypsin / Q000494:pharmacology
chemical_list: D003573:Cytochrome b Group; D003574:Cytochrome c Group; C023646:cytochrome b561; D014357:Trypsin; D001205:Ascorbic Acid