A Study on the Distribution of Cytochrome-c-oxidase Subunit in the Cristae of Mitochondria

미토콘드리아 크리스테에 존재하는 cytochrome-c-oxidase의 단백질 소단위 분포에 관한 연구

The topology of the enzyme has been investigated by biochemical studies including chemical labeling and cross linking. Thirteen subunits(polypeptides) of the cytochrome-c-oxidase have localistic characteristics of existing in the matrix side or cytoplasmic side in the mitochondria. In order to observe the distribution of the enzyme subunit on the mitochondria membrane, immunogold-labeling methods were employed. Antibody was obtained from the serum of immunized rabbit with enzyme subunit antigen which was obtained from cytochrome-c-oxidase of the beef heart muscle mitochondria. Beef heart muscle tissue as a tissue antigen was stained with immunized rabbit IgG and protein A gold complex. Electron microscopy has identified the existance of cytochrome-c-oxidase subunit $Mt_I,\;Mt_{II}\;and\;Mt_{III}$ on the membrane of cristae and outer chamber of mitochondria and the subunit $C_{IV}$ on the membrane of cristae and matrix of mitochondria. Particularly, the subunit $C_{IV}$ was also observed to exist in the sarcoplasm of muscle tissue.