The effect of pyruvic acid thiosemicarbazone on ornithine carbamoyl transferase ofLycopersicon esculentum Mill

The pyruvic acid thiosemicarbazone was found to inhibitin vitro the soluble ornithine carbamoyl transferase as well as the enzyme in a mitochondria-rich cell fraction. For proving the inhibition of ornithine carbamoyl transferase in mitochondria-rich fraction a new method for DEAE-thin-layer chromatography of radiocarbon labelled citrulline and ornithine was used. The mitochondria prepared by discontinuous sucrose density gradient centrifugation are physiologically active and oxidized succinate under state 3 conditions. The respiratory control ratio was determined to 3.3. The results obtained show that this analogue of pyruvic acid is an inhibitor of ornithine carbamoyl transferase.