The identification of the site of action of NN'-dicyclohexylcarbodi-imide as a proteolipid in mitochondrial membranes.
Mitochondrial membranes were incubated with NN'-dicyclohexyl[(14)C]carbodi-imide, which irreversibly inhibited the partial reactions of oxidative phosphorylation by 95-100%. Solutions of the membranes were analysed on polyacrylamide gels. Of the radioactivity recovered from the gels 90% was shown to be associated with a single protein of molecular weight about 10000. The radioactive protein and associated phospholipid was solubilized from the membrane by extraction with chloroform-methanol mixtures and was concentrated 50-fold by solvent fractionation and adsorption chromatography on Sephadex LH-20. Several protein-radioactivity peaks were obtained by Sephadex LH-20 chromatography. However, 90-100% of the radioactivity in each peak was shown to be associated with a single protein similar to the major radioactive protein observed in electrophoretograms of the membrane solutions. It is concluded that dicyclohexylcarbodi-imide inhibits mitochondrial oxidative phosphorylation by reacting covalently with a group on this chloroform-methanol-soluble protein. The possible role of this protein in oxidative phosphorylation is discussed.
D000179:Acrylates; D000818:Animals; D001665:Binding Sites; D002247:Carbon Isotopes; D002417:Cattle; D002845:Chromatography; D003510:Cyclohexanes / Q000378:metabolism*; D003911:Dextrans; D004589:Electrophoresis, Disc; D005782:Gels; D007094:Imides / Q000378:metabolism*; D066298:In Vitro Techniques; D008074:Lipoproteins / Q000378:metabolism; D008566:Membranes / Q000378:metabolism*; D008931:Mitochondria, Muscle / Q000378:metabolism*; D008970:Molecular Weight; D009206:Myocardium / Q000378:metabolism; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010743:Phospholipids
D000179:Acrylates; D002247:Carbon Isotopes; D003510:Cyclohexanes; D003911:Dextrans; D005782:Gels; D007094:Imides; D008074:Lipoproteins; D010743:Phospholipids