X, A. 1 



Pratt: Papain 



23 



Table XIX. — Effect of hydrocyanic acid on papain digestion of milk 



protein. 



No. o£ 

 flask. 



Milk. 



Water. 



Papain 



solution. 



Papain. 



Hydro- 

 cyanic 



acid 

 solution. 



Hydro- 

 cyanic 

 acid. 



Protein 

 undi- 

 gested. 



Protein 



di- 

 gested. 



Protein 



di- 

 gested. 



Parts of 

 protein 

 digested 

 by 1 part 

 papain. 





cc. 



ec. 



cc. 



mg. 



cc. 



Per cent. 



mg. 



mg. 



Per cent. 





1 



25 



15 



10 



50 







0.00 



270 



881 



76.6 



17.6 



2 



25 



14 



10 



60 



1 



0.02 



197 



954 



82.8 



19.1 



3 



25 



13 



10 



50 



2 



0.04 



178 



973 



84.5 



19.5 



4 



25 



12 



10 



60 



3 



0.06 



196 



955 



83.0 



19.1 



6 



25 



11 



10 



50 



* 



0.08 



200 



951 



82.6 



19.0 



« 



25 



10 



10 



50 



5 



0.10 



189 



962 



83.5 



19.2 



7 



25 



9 



10 



50 



6 



0.12 



181 



970 



84.2 



19.4 



8 



25 



8 



10 



50 



7 



0.14 



179 



972 



84.4 



19.4 



9 



25 



7 



10 



50 



8 



0.16 



178 



973 



84.4 



19.4 



10 



25 



6 



10 



60 



9 



0.18 



179 



972 



84.4 



19.4 



11 



25 



5 



10 



50 



10 



0.20 



187 



964 



83.7 



19.3 



Protein in blanks 1,151 milligrams. 

 Time of digestion, thirty minutes. 

 Temperature, 40°. 



The remarkable effect of hydrocyanic acid was not studied in 

 detail, as it has no bearing on the actual use or preparation of 

 papain. However, the difficulty of obtaining samples of pure 

 papain of known history made it worth while to examine the 

 digestion of peptone under these conditions. 



THE FORMATION OF TRYPTOPHANE FROM WITTE'S PEPTONE 



The following mixtures were prepared and incubated at 40°. 



Mixture 1. 



Peptone, 5 per cent 

 Papain, 1 per cent 

 Water, distilled 

 Toluol 



Mixture 2. 



Peptone, 5 per cent 



Papain, 1 per cent 



Hydrocyanic acid solution, 0.1 per cent 



Toluol 



Mixture S, control. 



Peptone, 5 per cent 



Hydrocyanic acid solution, 0.1 per cent 



Water, distilled 



Toluol 



ce. 



20.0 



20.0 



20.0 



0.5 



cc. 



20.0 



20.0 



20.0 



0.5 



ce. 

 20.0 

 20.0 

 20.0 



0.5 



