PROTAMINS AND HISTONS. 429 



The simplest group of proteids are the protamins. We owe the 

 discovery of these bodies as well as of nucleins to Miescher ^ who in 

 1874 isolated the first known representative of this group. By 

 means of dilute hydrochloric acid Miescher extracted from the sper- 

 matozoa of the salmon two new bodies protamin, a base, and 

 nucleinic acid. Piccard ^ in the same year extended somewhat the 

 investigation of Miescher by ascribing a different formula and 

 demonstrating the presence of xanthin bases in Miescher's prep- 

 arations. During the ensuing twenty years protamin was apparently 

 wholly forgotten and its nature remained therefore uncertain. Since 

 1894, however, we know through the labors of Kossel and his pupils 

 that Miescher's substance is one of a number of closely allied bodies. 

 For this group Kossel' reserves the original term protamin and 

 designates the individual compounds according to their source. 

 Thus, Miescher's protamin since it is derived from the salmon is 

 known as salmin ; that from the sturgeon becomes sturin ; while the 

 herring yields dupein. To these may be added scombrin * from the 

 spermatozoa of the mackerel ; cyclopierin ° from the Cyclopterus 

 lumpus (sea-hare) ; aodpenserin ^ from Accipenser stellatus ; and 

 silurin from the shad (Silurus glanis). From tubercle bacilli RuppeF 

 isolated a protamin to which he has given the name tuberculosamin. 

 A similar body it may be stated has been obtained from the colon 

 bacillus by Vaughan. The closely related histon bodies are considered 

 on p. 434. 



From the evidence thus far gathered it is clear that the protamins 

 are by no means widely distributed in nature. As a rule they are 

 present in the mature spermatozoa of fish. The immature sperma- 

 tozoa on the other hand are believed to contain chiefly histon. Ap- 

 parently, protamins are not present in the spermatozoa of the higher 

 animals. Miescher failed to find it in those of the steer and Math- 

 ews' likewise failed to isolate it from the steer and boar. 



The one property which is common to all proteids, so far as our 

 knowledge at present extends, is the formation of hexon bases on 

 cleavage. From the table on p. 426 it will be seen that arginin is 

 present in remarkably large quantity in the several protamins. 

 Moreover, these bodies yield the biuret reaction and are converted 

 by trypsin into " protons," the analogues of pepton, and eventually 

 into the hexon bases. It is because of these facts that the protamins 

 are regarded as the simplest of proteids. In the spermatozoa pro- 

 tamin undoubtedly exists in a salt-like combination with nucleinic 



1 ZeUs. physiol. Chem., 22, 177. 

 'Berkhte, 7, 1714. 



^Zeits. physiol. Chem., 22, 180, 1896. 

 ••ZeUs. physiol. Chem., 26, 524, 1898. 

 ^Zeits. physiol. Chem., 28, 313, 1899. 

 ^Zeiis. physiol. Chem., 32, 200, 1901. 

 ''Zeits. physiol. Chem., 26, 231, 1898. 

 ^Zeits. physiol. Chem., 23, 399, 1897. 



