426 



Histon and its Preparation 



[April 



3. Characteristic precipitation reactions (Bang). Table 3 

 presents a summary of the characteristic precipitation tendencies of 

 histons, as specified by Bang. 



TABLE 3 



Data pertaining to the precipitation of histons (Bang) 



Kind 



1. Goose-blood (12) . . 



2. Goose-blood (2) . . . 



3. Thymus 



4. Thymus 



5. Salmin (22) 



6. Arbacin (21) 



7. Arbacin (21) 



8. Globin (23) 



9. Scombron (2) 



10. Para-histon (9) . . . . 



11. Gadus (16) 



12. Lota (8) 



13. Hen-blood (i) 



14. Centrophorus and 



Spharechinus (15) 



Nature of product 

 in aqueous Solution 



NaCl ppt. 

 NaOH ppt. 

 Histon-HCl 

 NaCl ppt. 

 Histon-HCI. 

 Histon-H2S04 

 Ale. ppt. (NH4OH 



sol.) 

 NH4OH ppt. 

 NaOH ppt. 

 Ale. ppt. 

 NaCl ppt. 

 Histon-HCI 

 Histon-HCl 



Reagents 



B 



ÄS 

 X 



. c 



Pi 

 Pi 



p4 

 p4 

 p2 



N6 



N6 



pl 



p2 



N 

 P 

 Pi 



p2 



p2 

 p2 

 p2 

 p2 



N5 



N6 

 p2 

 p2 



N 



p2 

 p2 



P 



p* 



P 



P 



P 



P 



P 

 P 



N 

 P 



N 



N* 



N 



N 



N 



N 



N 

 N 

 N 

 N 



N 



No data given. 



N 



2 n 



e s 



p3 



P 



P 



pe 

 P« 



N6 

 p6 



o « 



E- 



5 o 

 2 E 



p3 



P 



P 



p3 

 P« 



p3 



ps 



P 

 P 

 P 

 P 



P 



P« 



P 



o o 





-■ 



_ 3 



p3 



p3 



pe 



P 

 P 

 P 

 P 



P 

 P 

 P 

 P 

 P 

 P 



4. General precipitation reactions. Additional general data 

 on the precipitation of histons are given in Table 4. 



5. Color reactions. Available data pertaining to the responses 

 of histons to protein color tests are indicated in Table 5. 



* P = precipitated ; N = not precipitated. 

 ^ Soluble in excess of the reagent. 

 ''Insoluble in excess of the reagent. 



* From neutral but not f rem alkaline Solutions. 



* Thymus is apparently insoluble in ammonia in the absence of salts pro- 

 vided only a small amount of ammonia is used to precipitate it. Once formed 

 a large excess of ammonia can be added without dissolving the precipitate. 



" No precipitate with ammonia unless the Solution is very concentrated er 

 alcohol is present. 



' In neutral or weak alkaline Solution. 



