Abstract
An improved method for preparation of pure RNase T1 was described. The purified enzyme was demonstrated to be homogeneous by moving boundary electropdoresis and some other criteria, and the isoelectric point was determined to lie around pH 2.9. The enzyme was shown to be free from sugar and the nitrogen content was determined to be 16.5 per cent. The amino acid composition of the enzyme was determined. The corrected analytical values accounted quantitatively for the weight and the nitrogen content of the enzyme. The analyses indicated the following 105 amino acid residues in the enzyme molecule (mol. wt. 11,127): Asp15 Thr6 Ser17 Glu10 Pro4 Gly12 Ala7 (Cys-)4 Val7 Ileu2 Leu3 Tyr3 Phe4 Lys1 His3 Arg1 Try1 (–CONH2)11.