Studies on protein synthesis by protoplasts of saccharomyces carlsbergensis III. Studies on the specificity and the mechanism of the action of ribonuclease on protein synthesis

Abstract

In this paper, the experimental results are presented of a continued study on the specificity and the mechanism of the inhibition by ribonuclease of protein synthesis in protoplasts of Saccharomyces carlsbergensis. By comparing the effects of native pancreatic ribonuclease with those of heat-denatured enzyme and protamine, it is shown that at least part of the observed inhibition of protein synthesis has to be attributed to the enzymic action of ribonuclease.

The enzyme was found to cause both a lysis of the protoplasts and an inhibition of protein synthesis. Mg2+ was found to abolish the lysing action of RNAase, whereas protein synthesis remained inhibited for 50–90%. From the data it is concluded that RNAase inhibits protein synthesis primarily by its action on the yeast cell membrane.