Incorporation of amino acids into microsomal proteins of normal and malignant tissues.

Rapidly proliferating normal and malignant cells had a greater initial rate of amino acid incorporation into mierosomal proteins than did normal cells. The rate of mierosomal protein renewal in Novikoff hepatoma was greater than that of liver cells. The initial rates of amino acid incorporation into hepatoma and liver ribonueleoprotein particles were approximately equal. The soluble fractions of the liver and hepatoma cells were essentially interchangeable. Hepatoma mierosome and pH 5 enzymes had a greater proportion of ribonucleie acid (RNA) in RNA plus proteins than did normal liver mierosomes.