Purification and Properties of Horse Pancreatic Ribonuclease

Abstract

1. Two ribonucleases [EG 2.7.7.16], RNase Eq₁ and Eq₂,were purified 180 and 130 fold, respectively, by successive IRG-50 and phos-phocellulose column chromatography after ammonium sulfate fractiona-tion of horse pancreas extract 2. RNases Eqj and Eqt were found to be different from RNase A in respect to the elution position on IRG-50 column chromatography. 3. RNase Eqt was homogeneous in both sedimentational and electro-phoretic analyses, whereas RNase Eqs was found to be still heterogeneous in electrophoretic examination. 4. RNases Eqt and Eqt have properties very similar to those of RNase A in respect to molecular weight and heat stability. 5. RNases Eqi and Eqs have the base specificity similar to that of RNase A and are markedly inhibited by Cu⁺⁺, Zn⁺⁺and Hg⁺⁺