CHAPTER V. 



THE NITROGENOUS DERIVATIVES OF THE ALBUMINS. 



THE PROTAMINS. 



THE term protamin was first introduced by Miescher to designate 

 a basic substance which he was able to isolate from the spermatozoa 

 of the salmon, and which is there apparently united with a nucleinic 

 acid radicle. Kossel then showed that a very similar substance can 

 be obtained from the spermatozoa of the sturgeon ; and his pupil, 

 Ku raj elf, isolated a third body of this order from the spermatozoa 

 of the mackerel. It was thus shown that different protamins occur 

 in nature, and the use of the term has since been extended to the 

 entire class. Miescher's original protamin is now spoken of as 

 salmin, and is identical with KossePs clupein, which was obtained 

 from the spermatozoa of the herring. The two other protamins 

 which have thus far been isolated are termed sturin and scombrin, 

 according to their origin from the sturgeon and the mackerel, re- 

 spectively. 



According to Kossel, the protamins are essentially albumins of 

 the lowest order, and he assumes that a radicle of this kind forms 

 the nucleus of all the more complex albumins. This assumption is 

 largely based upon the observation that all protamins yield certain 

 decomposition-products, which may also be obtained from the various 

 albumins. 



These products are the so-called hexon bases, and comprise his- 

 tidin, arginin, and lysin. But whereas sturin and all the complex 

 albumins which have been examined in this direction give rise to 

 the formation of all three of these bodies apparently, salmin (clupein) 

 and scombrin only contain the arginin group. It consequently fol- 

 lows that the protamin radicle of the complex albuminous molecule 

 must be of the nature of sturin. Whether other complex albumins 

 exist which also contain the salmin or scombrin radicle is as yet 

 unknown. 



As regards the quantitative relations which exist between the three 

 hexon bases within the sturin molecule, our knowledge is incom- 

 plete. Kossel suggested that six molecules here unite in such a 

 manner that every two combining molecules lose two molecules of 

 water, and that the formation of sturin might hence be represented 

 by the equation : 



C 6 H 9 X 3 2 -f 3C 6 H 14 N 4 O a + 2C 6 H, 4 N 2 2 == C^H^A + 5H 2 O 

 Histidin. Arginin. Lysin. Sturin. 



However this may be, it must not be supposed that the qnantita- 



