136 



LECTURE VII. 



extended our knowledge of them; so much so, that most of their funda- 

 mental constituents are already well established. Kossel and his students 

 have also found protamines in the spermatozoa of other fishes. They 

 resemble one another very closely, although they are not identical, as is 

 indicated by their percentages of mono- and di-amino acids. The pro- 

 tamine group is very well defined. They contain, above all, a very large 

 amount of bases. Arginine is the main cleavage-product of the protamines. 

 The amount varies between 58-84 per cent according to the origin of the 

 protamine. They also contain mono-amino, as well as the di-amino, acids, 

 as we shall see later. To assign to the protamines a particular position 

 among the albuminous substances would certainly be arbitrary and unjusti- 

 fiable at present. They are closely related to all the remaining proteins, and 

 are formed from them. There is also no justification for considering them 

 as the simplest proteins. Although one of the cleavage-products of the 

 protamines, arginine, is found in large amount, it must not be forgotten 

 that other amino acids are also present, and that the constitution of the 

 protamines may be just as complicated as that of other proteins. 



The protamines can be purified, which is of great advantage in their 

 preparation. The free protamines are obtained pure only with difficulty. 

 They are best obtained in the form of sulphates, and then changed over 

 into chlorides. The latter can be precipitated from methyl alcohol solution 

 by means of platinum chloride. M. Goto 1 has analyzed these platinum 

 salts, and obtained the following values: 



Sulphur has not yet been discovered in the protamines, and is probably 

 absent. We are not at present aware of any reason why a lower 

 molecular weight should be assigned to them than to the other proteins. 

 The protamines are not coagulated by heat. While the ordinary proteins 

 are precipitated by the alkaloid reagents (for instance, phospho-tungstic 

 acid) only in acid solution, and the histons in neutral solution, the prot- 

 amines will be even thrown out in alkaline solution. The protamines can be 

 salted-out by ammonium sulphate and sodium chloride. 



The protamines have toxic properties; 2 15-18 mg. of scombrine, salmine, 



1 M. Goto: Z. physiol. Chem. 37, 94 (1902). 



3 W. H. Thompson: Z. physiol. Chem. 29, 1 (1900). 



