ENZYMES OF THE TUBERCLE BACILLUS 



145 



contained 0.05 cc. of 0.1 per cent yeast nucleic acid in distilled 

 water and was considered as 100 per cent. The total volume in 

 this experiment was 10 cc. instead of 6 cc. as above and to this 

 was added 1 cc. 0.1 per cent freshly prepared yeast nucleic acid 

 solution. The results obtained, in percentage of the standard 

 nucleic acid solution, were as follows: 



* The turbidity produced in the test solution was greater than that accounted 

 for by the nucleic acid added. No explanation has been found for this e.xcept 

 the fact that certain substances may have been liberated by the autolysis 

 of the tubercle bacilli which combine with the precipitant to form a turbidity. 



t The turbidity of the heated control after the albumin precipitant#ras added 

 was also greater than that accounted for by the nucleic acid added but less than 

 that of the unheated test. 



Summary. The autolysate from tubercle bacilli possesses an 

 enzyme capable of splitting nucleic acid into simpler form. 



Experiment II. In an attempt to corroborate the findings of 

 experiment I by amino acid determinations, the following 

 experiment was performed and the results are given for what 

 they may be worth. 



Two cubic centimeter amounts of bacillary residue were 

 prepared in four tubes. Sufficient hydrochloric acid was added 

 in one tube to make the final strength 0.1 per cent; to the second 

 tube sufficient hydrochloric acid to make the final strength 

 0.1 per cent and 3 cc. 0.1 per cent acid caseinate; the third was 

 kept as a neutral control; and to the fourth was added 3 cc. 0.1 

 per cent nucleic acid. All were diluted to 10 cc. with physio- 

 logical salt solution, 2 cc. toluene and 1 cc. chloroform was 

 added and the tubes incubated at 37°C. At various intervals 

 definite amounts of the solution were withdrawn and tested for 

 amino acid a nitrogen content. 



