Identification and primary structure of the cardiolipin-binding domain of mitochondrial creatine kinase.
It was recently shown that the mitochondrial isozyme of heart creatine kinase binds to cardiolipin on the outer half of the inner membrane [Müller, M., et al. (1985) J. Biol. Chem. 260, 3839-3843]. The enzyme has now been extracted and purified to homogeneity from rat heart mitochondria, and cleaved with CNBr. The fragments have been separated on an FPLC system using a Mono Q HR 5/5 column. Only one of these binds to cardiolipin-containing liposomes and has thus been identified as the cardiolipin-binding domain of the enzyme. Its amino acid sequence has been determined. The fragment contains 25 amino acids and corresponds to the N-terminal region of the protein. The binding of the fragment of cardiolipin-containing liposomes was inhibited by adriamycin. Another and larger CNBr fragment could be specifically labelled with periodate-oxidized (di-aldehyde) ATP and has thus been identified as the ATP-binding domain. Chemical modification of the basic amino acids Lys and Arg of the enzyme abolished its binding to cardiolipin.
Cheneval
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Laboratory of Biochemistry, Swiss Federal Institute of Technology, Zürich.
Carafoli
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D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002308:Cardiolipins / Q000378:metabolism*; D003402:Creatine Kinase / Q000378:metabolism*; D003488:Cyanogen Bromide; D008854:Microscopy, Electron; D008929:Mitochondria, Heart / Q000201:enzymology*; D008969:Molecular Sequence Data; D010446:Peptide Fragments; D051381:Rats; D013329:Structure-Activity Relationship
D002308:Cardiolipins; D010446:Peptide Fragments; D000255:Adenosine Triphosphate; D003402:Creatine Kinase; D003488:Cyanogen Bromide