Factors influencing the incorporation of amino acid into the protein of microsome and mitochondria preparations of rat liver and liver tumour

Publisher Website
Google Scholar
Abstract
After the incubation of microsomes and pH 5 fraction of liver and liver tumor with C14-leucine, the radioactivity of the tumor-microsomal protein was lower than that of liver. When liver microsomes were incubated with tumor pH 5 fraction, instead of liver pH 5 fraction, less incorporation resulted. The adenosine triphosphate(ATP)-dependent incorporation of leucine and lysine into the ribonucleic acid of pH 5 fraction of liver tumor was lower than into that of normal liver. The ATP-dependent incorporation of Cl4-leucine into preparations of liver and tumor mitochondria was studied. Incorporation into the mitochondrial protein was higher in the presence of cell sap than in its absence. Under all experimental conditions the amino acid incorporation into tumor mitochondria was lower than into liver mitochondria. The stimulating action of tumor cell sap on liver mitochondria was as great as that of liver cell sap. The tumor pH 5 fraction was less effective than that of liver in stimulating mitochondrial incorporation. Ribonuclease stimulated the incorporation of amino acids into liver-mitochondrial protein in the absence of cell sap, but reduces the incorporation stimulated by cell sap.