196 EMIL L. SMITH, ROBERT L. HILL AND J. R. KIMMEL [11 

 One of the best methods of checking the results of degradation experi- 

 ments is to be able to add up, for a given experiment, the amino acids 

 released and the amino acids found in the undegraded residual mercuri- 

 papain. Thus far, only two such experiments have been performed. In 

 Experiment I, the liberated amino acids v^ere collected by dialysis and 



Table 8 



ANALYSIS OF AMINO ACIDS LIBERATED AND THOSE 



REMAINING IN MERCURIPAPAIN AFTER HYDROLYSIS WITH 



AMINOPEPTIDASE (LAP) 



In Experiment I, the undegraded residual mercuripapain was collected by isoelectric 

 precipitation. In Experiment II, the degraded material was isolated by the chromato- 

 graphic procedure shown in Fig. 5. 



* Assumed value. 



t For comparison with intact papain, the total number of tyrosine, tryptophan and 

 proline residues has been assumed to be the same as in the original papain. 



analyzed as described above. A separate aliquot was oxidized with per- 

 formic acid for determination of cysteic acid. The residual mercuripapain 

 was then precipitated isoelectrically, oxidized with performic acid, hydro- 

 lyzed with 6 N-HCl in the usual manner, and the hydrolysate was analyzed. 

 The results are given in Table 8. 



