In vitro association of mitochondrial ATP- dependent protease with mitochondrial heat-shock proteins.

Specific antibodies against the mitochondrial ATP- dependent protease and heat-shock proteins were used to study the association of these proteins with an abnormal bacterial protein, CRAG. It was shown that the mitochondrial ATP-dependent protease from rat liver and Zajdela hepatoma bind to the CRAG protein and that this binding was mediated through the heat-shock proteins. It was also demonstrated that the protease associated with heat-shock proteins is capable of degrading large proteins as well as small peptides in an ATP-dependent fashion. Zajdela hepatoma mitochondria, with enhanced mitochondrial proteolysis, were shown to contain more ATP-dependent protease associated with heat-shock proteins.