[Respiration-stimulated activation of DNAase I associated with mitochondria].

The influence of respiration and Ca++ transport in the liver mitochondria on the activation of DNAase I, associated with these organelles, was studied. It was shown that 96% of the total activity of this enzyme in mitochondria is in the latent state. Aeration of the mitochondrial suspension leads to a sharp increase in the enzyme activity. The activation of DNAase I is inhibited by EGTA addition (optimal pH 8.0), and stimulated in mitochondria, releasing Ca++. It is concluded that the activation of DNAase I is dependent on the state of cellular energetics. Participation of mitochondrial phospholypase A, activated by the Ca++ release from mitochondria during DNAase I activation is suggested.