Crane 1956 Biochim Biophys Acta
|Crane FL, Glenn JL, Green DE (1956) Studies on the electron transfer-pathway IV. The electron transfer particle. Biochim Biophys Acta 22:475-87.|
Abstract: The preparation and properties of an electron transfer particle (ETP) obtained from beef heart mitochondria are described. ETP catalyzes the oxidation of 5.7 μmoles DPNH and 2 μmoles succinate per min per mg at 38°. This specific activity is 3 to 5 times greater than that of the original mitochondrial suspension. These two oxidative reactions are profoundly influenced by 1) concentration of phosphate, 2) the presence of metal complexing agents, and 3) the ionic strength of the medium.
Preparations of ETP contain flavin, cytochromes a, b and c1, non-heme iron and copper in constant proportions as well as cytochrome c in variable quantity depending upon the conditions of isolation. Both flavin and hemes are reducible by either substrate and to the same complete extent. Preparations of ETP from which the bulk of cytochrome c has been removed show no requirement for added cytochrome c in the oxidation of DPNH by molecular oxygen, whereas a partial requirement for cytochrome c in the oxidation of succinate is demonstrable under some but not all conditions. The exposure of ETP to deoxycholate leads to a particle which can interact readily with external cytochrome c. Procedures which induce fragmentation of ETP are also described. The significance of the fact of the constant composition of ETP for the dynamics of electron transport is discussed. • Keywords: Electron transfer particle, Beef heart
Organism: Bovines Tissue;cell: Heart Preparation: Isolated mitochondria, SMP Enzyme: Complex IV;cytochrome c oxidase
Coupling state: OXPHOS