The role of creatine kinase in inhibition of mitochondrial permeability transition

Cyclosporin A sensitive smelling of mitochondria isolated from control mouse livers and from the livers of transgenic mice expressing human ubiquitous mitochondrial creatine kinase occurred in the presence of both 40 mu M calcium and 5 mu M atractyloside which was accompanied by a 2.5-fold increase over state 4 respiration rates, Creatine and cyclocreatine inhibited the latter only in transgenic liver mitochondria, Protein complexes isolated from detergent solubilised rat brain extracts, containing octameric mitochondrial creatine kinase, porin and the adenine nucleotide translocator, were reconstituted into malate loaded lipid vesicles, Dimerisation of creatine kinase in the complexes and exposure of the reconstituted complexes to >200 mu M calcium induced a cyclosporin A sensitive malate release, No malate release occurred with complexes containing octameric creatine kinase under the same conditions. (C) 1997 Federation of European Biochemical Societies.