Open AccessTissue-specific regulation of bovine heart cytochrome-c oxidase activity by ADP via interaction with subunit VIa.
Author(s) -
G. Anthony,
Achim Reimann,
Bernhard Kadenbach
Publication year - 1993
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.90.5.1652
Subject(s) - cytochrome c oxidase , electron transport complex iv , protein subunit , oxidase test , biochemistry , enzyme , cytochrome c , cytochrome , biology , microbiology and biotechnology , chemistry , mitochondrion , gene
The activity of reconstituted cytochrome-c oxidase (EC 1.9.3.1) 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.