[Mitochondrial localization of cytochrome c1 with specific antibodies]

A specific antibody against cytochrome c1 (pig heart mitochondria) has been obtained. It inhibits the electron transport of the respiratory chain in the intact mitochondria at the cytochrome c1 site of inner mitochondrial membrane ; but it has no effect on the isolated submitochondrial particles (inside-out inner mitochondrial membrane vesicles free of any outer membrane or outside-out inner membrane). Thus the topologic position of cytochrome c1 in the inner mitochondrial membrane is asymetrically lcoated on the outer side of the inner mitochondrial membrane. These results agree with our previous researches on ATP-ase and cytochromes b, c and a, indicating the location on the inner side for the first one, transmembranous for the last one, on the outer side for the others respiratory chain components. Thus the electron transport from cytochrome b to a takes place in the outer region of inner mitochondrial membrane and the transmembranous location of cytochrome-oxidase facilitates the transfer of the electrons to oxygen.