Alanine residues ribonuclease

Several studies with ribonuclease suggest that ( ertain peptide bonds of a given kind are more available to proteolysis than others (reviewed by Scheraga and Rupley, 1962). Thus, pepsin hydrolyzes one bond between residues 120 and 121 which leads to inactivation of the molecule (Anfinsen, 19.56). Subtilisin (Richards and Vithayathil, 1959) rapidly splits a single bond between alanine and serine at residues 20 and 21. Carboxypeptidase... 

However, the specific activities of certain amino acid residues are significantly different when the two reagents are compared. Thus, the specific activity of lysine in ribonuclease labeled with TI is lower and that of alanine is higher than for labeling with HST. It appears, therefore, that some distortion can occur when tritiated scavengers are employed. It was pointed out earlier that a possible explanation of such distortions might lie in the reactions by which the radicals produced... 

In part B are given the ribonuclease and taka-diastase sites of action with the first 11 residues of the alanine tRNA (after R.W. Holley). 

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