THE EFFECTS OF RIBONUCLEASE ON THE RIBONUCLEIC ACID AND ENZYME ACTIVITIES OF MICROSOMES ISOLATED FROM RAT LIVER HOMOGENATES

1. The RNA of isolated rat liver microsomes is readily accessible to ribonuclease digestion. About 85% of the RNA-ribose is removed by the nuclease; data in the literature suggest that the rest remains in smaller polynucleotides rather than RNA per se. 2. Digestion of microsomes with ribonuclease dissolved in glycyl-glycine buffer, pH 7.0, has no effect upon the activities of the enzymes studied: glucose-6-phosphatase, esterase, triacetic acid lactonase, adenosine-5'-phosphatase, acid phosphatase, adenosine triphosphatase, and succinoxidase. 3. Digestion with ribonuclease dissolved in water has no effect upon the acid phosphatase and adenosine-5'-phosphatase activities, while esterase, adenosine triphosphatase and succinoxidase activities are somewhat lower. Glucose-6-phosphatase activity is markedly reduced, as it is by incubation of microsomes with either water or buffer alone.