Mechanismen der Proteinsynthese, II. Reinigung der Ribosomen ausEscherichia colivon Nucleasen und deren Charakterisierung

Abstract
After purification of E. coli A 19 ribosomes by 5-7 centrifugations with 0. 5 M NH4CI in standard buffer and subsequent dialysis against 0. 2mM MnCl2, the remaining ribonucleolytic activity is reduced to 10-3-10-4 times its original level. The nucleolytic activity washed away corresponds to RNase II. A residual, apparently exo-nucleolytic activity, remaining on the ribosomes after 5 times washing with NH4O differs in its ion requirement from nucleolytic enzymes previously known.