Tissue-specific regulation of bovine heart cytochrome-c oxidase activity by ADP via interaction with subunit VIa

Proc Natl Acad Sci U S A. 1993 Mar 1;90(5):1652-6. doi: 10.1073/pnas.90.5.1652.


The activity of reconstituted cytochrome-c oxidase (EC from bovine heart is stimulated by intraliposomal ADP but not by NaCl of the same ionic strength. A monoclonal antibody which reacts with subunits VIa-H (heart-type) and VIc, due to the evolutionary relationship between these subunits, also stimulates the activity of the enzyme from bovine heart but not from bovine liver. The antibody induces a conformational change in the heart enzyme but not in the liver enzyme, as shown by the visible difference spectrum. Preincubation of heart cytochrome-c oxidase with the antibody prevents stimulation of activity by intraliposomal ADP after reconstitution in liposomes. Reconstituted liver cytochrome c oxidase is not stimulated by intraliposomal ADP. The data suggest tissue-specific regulation of the activity of cytochrome-c oxidase by ADP via interaction with the matrix domain of subunit VIa-H.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate / metabolism*
  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal
  • Cattle
  • Electron Transport Complex IV / chemistry
  • Electron Transport Complex IV / immunology
  • Electron Transport Complex IV / metabolism*
  • Kinetics
  • Macromolecular Substances
  • Membrane Proteins / chemistry
  • Membrane Proteins / immunology
  • Membrane Proteins / metabolism
  • Mitochondria, Heart / enzymology
  • Mitochondria, Liver / enzymology
  • Molecular Sequence Data
  • Myocardium / enzymology*
  • Sequence Alignment


  • Antibodies, Monoclonal
  • Macromolecular Substances
  • Membrane Proteins
  • Adenosine Diphosphate
  • Electron Transport Complex IV