[Metabolism and various properties of proteinase controlling catalase metabolism in rat liver mitochondria].

The Mg,ATP-dependent serine proteinase (Mr = 50 kD; pH optimum 8.0) was isolated and purified 750-fold. The substrate specificity of the enzyme to some protein substrates (catalase, aldolase, uratoxidase, superoxide dismutase, albumin, cytochrome c, insulin) was investigated. The proteinase shows an affinity for proteins whose molecular mass is more than 100 kD. Some quantitative parameters of the enzyme metabolism, e.g., rate constants for synthesis and degradation of serine proteinase and the time of functioning of the de novo synthesized protein, were investigated.