On the function of multiple subunits of cytochrome c oxidase from higher eukaryotes

Tissue‐specific genes code for polypeptide VIa of bovine liver and heart cytochrome c oxidase

“…The functional meaning of cytochrome c oxidase isoenzymes may be understood by a tissue-specific regulation of respiratory function including electron-and/or proton-translocation in complex IV of the respiratory chain of the mitochondrial membrane (see [2]). This assumption is supported by different kinetic properties found for cytochrome c oxidases of bovine liver and heart [5,10].…”

“…Cytochrome c oxidase from higher eucaryotes is composed of 12-13 different protein components (review [1][2][3]). This was concluded from: (i) The occurrence of 12 protein bands after SDS gel electrophoresis in enzyme preparations from many species and tissues [4,5 ]; (ii) The isolation of 12 different polypeptides from bovine heart cytochrome c oxidase by gel chromatography, and the proof of 12 different N-terminal amino acid sequences [6]; (iii) The occurrence of all components in the complex in stoichiometric amounts [4,7]; (iv) The immunoprecipitation of 12 polypeptides from a mitochondrial Triton X-100 lysate with a specific antiserum against subunit IV [8].…”

Purification of all thirteen polypeptides of bovine heart cytochrome c oxidase from one aliquot of enzyme Characterization of bovine fetal heart cytochrome c oxidase

“…Beef heart cytochrome c oxidase can be resolved into 13 different polypeptides using the highly resolving gel system of Kadenbach and Merle [8], as shown in fig. 1 for both adult and fetal forms of the enzyme.…”

“…These are coded for on mitochondrial DNA; they presumably contain the prosthetic groups and are the catalytic core [1,2]. In addition, Correspondence (Present) address: S. Takamiya, Dept of Parasitology, Juntendo University, School of Medicine, 2-l-l Hongo, Bunkyo-Ru, Tokyo 113, Japan cytochrome c oxidase in eukaryotes contains a number of cytoplasmically made polypeptides, ranging from as few as four in lower eukaryotes such as Dictyostelium [6], to six in yeast or Neurospora [7], and as many as ten in mammals [8,9]. It is these cytoplasmically made polypeptides which show tissue-specific and possibly, developmentally different isoenzyme forms, as demonstrated by differences in size and N-terminal sequences [ 1 l] and different immunoreactivities (121 of some subunits.…”

Influence of buffer composition, membrane lipids and proteases on the kinetics of reconstituted cytochrome-c oxidase from bovine liver and heart

“…(B) The enzymes were reconstituted as described in Materials and Methods using asolectin or 90% asolectin and 10% cardiolipin as liposomal lipids. The activity was assayed polarographically as described in Materials and Methods in the buffer: 40 mM KC1, 10 (Fig. 4).…”