.32 ESSENTIALS OF CHEMICAL PHYSIOLOGY 



D. The Protamines 



These are basic substances which are combined with nuclein in 

 the heads of the spermatozoa of certain fishes. They resemble pro- 

 teids in many of their characters — e.g. they give Piotrowski's reaction 

 and some of the other tests for proteids. They are regarded by 

 Kossel as the simplest proteids. On hydrolytic decomposition, they 

 first yield substances analogous to the peptones, which are called 

 protones, and then they split up into simpler materials which are 

 mainly bases containing six atoms of carbon, and called in con- 

 sequence the hexone bases. These bases have the following names 

 and formulae : — 



Histidine GgHgNsOi 



Arginine C6Hi4N402 



Lysine C6H14N2O2 



Protamines differ in their composition according to their source, 

 and yield these products in different proportions. Thus salmine (the 

 protamine from the salmon) has the empirical formula C3oHg7Ni706, 

 and sturine (from the sturgeon) CggHgoNigO;. 



A good deal of work still remains to be done at these substances, 

 but the five which have hitherto been most fully worked at are 

 salmine, sturine, scombrine (from the mackerel), cyclopterine (from 

 Cyclopterus lumpus), and clupeine (from the herring). 



Of these salmine and clupeine appear to be identical; the 

 principal products of the decomposition of salmine, clupeine, and 

 scombrine are arginine, amido-valerianic acid, and a small quantity of 

 an unknown residue. 



Sturine yields these same products with lysine, and histidine in 

 addition, 



Cyclopterine yields the same products as sturine, with the addition 

 of an aromatic substance. 



The more complex proteids and albuminoids yield hexone bases, 

 and so Kossel considers that all these substances contain a prota- 

 mine nucleus. The more complex proteids, however, yield many 

 other products of decomposition in addition to these bases, of which 

 leucine (C6H,3N02) and tyrosine (C9H11NO3), an aromatic substance, 

 may be specially mentioned. Cyclopterine, which also yields an 

 aromatic substance, is thus an important chemical link between the 

 other protamines and the proteids proper. It is interesting to note 

 how many of these decomposition products contain six carbon atoms, 

 ^nd it reminds one that in the sugars obtained from starch there are 

 also six atoms of carbon. 



