134 THE PROTEIN SUBSTANCES. 



The hetero and protoproteoses are not, according to our present 

 views, the only primary proteoses. In the proteose fraction obtained 

 on saturating with ammonium sulphate in neutral liquids, \vhich should 

 contain secondary proteoses only, primary proteoses such as the gluco- 

 proteose (PICK), which contains a carbohydrate group and the so-called 

 synproteose (HOFMEISTER l ) occur. It is no longer sufficient to consider 

 an unequal ability to be salted out, as an essential difference between 

 the primary and secondary proteoses. 



There is no doubt that there exists a large number of so-called pro- 

 teoses having various precipitation properties, and different other prop- 

 erties and new differences appear, while working with them according to 

 different methods. For example RONA and MiCHAELis 2 find that cer- 

 tain proteoses are precipitated by mastic emulsion while others are not. 

 Those that are precipitatable by mastic, can all be salted out, while all 

 those that can be salted out are not all precipitated by mastic. The 

 hetero- and protoproteoses act, according to ZuNZ 3 like strong protec- 

 tion colloids toward colloidal gold, which is not the case with the others, 

 and also, according to this worker, the so-called proteoses are more readily 

 precipitated by chondroitin-sulphuric acid and acetic acid than the so- 

 called secondary proteoses. According to HUNTER 4 only the primary 

 proteoses are precipitated by protamines while the secondary are not. 

 It is also possible that numerous intermediary members exist between 

 those proteoses which stand close to the original protein and those that 

 are further removed. The difficulties in isolation and purification of 

 these different members are so very great that the proteoses thus far 

 isolated must not be considered as chemical individuals. Under these 

 circumstances the above-mentioned differentiation and classification 

 of the various proteoses is of little value and a more detailed discus- 

 sion of the properties of the various proteoses thus far isolated is with- 

 out interest. 



It would be of great interest if certain differences in the chemical 

 structure of the different proteoses could be determined with certainty. 

 Such differences are claimed to have been found in certain cases. Thus 

 HART has found that the heteroproteose (from muscle syntonin) was 

 considerably richer in arginine and poorer in histidine than the proto- 

 proteose, and PICK has also found marked differences between the hetero- 

 and protoproteose from fibrin. The hetero-proteose yields very little 



1 Ueber Bau und Gruppirung der Eiweisskorper, Ergebnisse der Physiol., Jahrg. I, 

 Abt. 1, 783. 



2 Biochem. Zeitschr., 3. 



3 Arch, internat. d. Physiol., 1 and 5, and Bull. Soc. Scienc. med. et natur. Brux- 

 elles, 64. 



4 Journ. of Physiol., 37. 



