ACTION OF RIBONUCLEASE PREPARATIONS ON VIABLE YEAST CELLS AND SPHEROPLASTS.

Schlenk, F. (Argonne National Laboratory, Argonne, Ill.), and J. L. Dainko. Action of ribonuclease preparations on viable yeast cells and spheroplasts. J. Bacteriol. 89:428-436. 1965.-Recrystallized pancreatic ribonuclease releases more than half of the ultraviolet-absorbing cellular constituents of Candida utilis and Saccharomyces cerevisiae. The presence of salts and buffer interferes with the action of the enzyme on the cytoplasmic membrane, and intracellular constituents show a similar inhibitory effect. Polymerized ribonuclease and conformational isomers cannot penetrate the pores of the yeast cell wall, but they are effective on the membrane of spheroplasts. All forms of the enzyme interfere strongly with the viability of the cells.