TWO DIFFERENT SPECIES OF CYTOCHROME b 5 IN ONE CELL

Cytochrome b 5 is traditionnaly extracted from liver microsomes. It is however known to be present in a number of other cell membrane fractions: nuclear membrane, Golgi membrane, plasma membrane, outer mitochondrial membrane. In the latter, it has been described to be part of a so-called rotenone insensitive NADH-cytochrome c reductase system.