PROTEOSES AND PEPTONES. 133 



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, which should 

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

 proteose (PICK), w.hich 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 in their investigation according to 

 different methods. For example RON A and MICHAELIS 2 find that certain 

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

 that are precipitable 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 protection 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 pre- 

 cipitated 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 pro- 

 teoses 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 a 

 more detailed discussion of the properties of the various proteoses thus 

 far isolated is without 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 proto-proteose from fibrin. The hetero -proteose yields very little 

 tyrosine and indol but abundant leucine and glycocoll, and about 39 

 per cent of the total nitrogen in a basic form. The protoproteose, 



1 Ueber Bau und Gruppirimg 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. 



