ix THE PROTAMINS 423 



and other salts of the heavy metals. Salmin is also precipitated by 

 chromic acid, potassium bichromate, and tannic acid, but not by 

 osmium tetroxide (Mann). 1 



Protamins are salted out by ammonium sulphate and sodium 

 chloride, but the exact precipitation-limits are not known. 



They also give with albumin and with the primary albumoses 

 precipitates which resemble histones very closely (Kossel). 



Of the salts, in addition to the picrate mentioned above, the 

 chromate of scombrin is also known. 2 Clupein sulphate is readily 

 soluble in hot water; 100 parts of cold water dissolve 1'62 parts; 

 when cooled to +2, or on the addition of ether, protamin sulphate 

 separates out as a dark oil. The refractive index and the specific 

 rotatory power of clupein sulphate is given by Kossel, 3 and that of 

 scombrin sulphate by Kurajeff. 2 



Peptic digestion leaves protamin unaltered, 4 while trypsin 4 and 

 erepsin 5 break it up into crystalline dissociation-products. As inter- 

 mediate products are formed peptone -like bodies, the 'protones/ 

 which differ from the protamins in giving a pure red biuret-reaction 

 and in not being able to precipitate albumin. 6 As regards percentage- 

 composition and dissociation-products Goto found no distinct difference 

 between protamins and protones. Goto found, on splitting up clupein 

 with hydrochloric acid, an increase in alkalinity, while with sulphuric 

 acid a diminution was noticed. How protones are related to kyrin is 

 mentioned on p. 201. 



Thompson 7 has shown that protamins in their toxic properties 

 resemble the albumoses formed by digestive enzymes. The toxicity 

 is great, for 15 to 18 milligrammes of salmin, clupein, and scombrin, 

 and 20-25 mg. of sturin per kilo, of dog, is sufficient to cause death. 

 The protones are much less toxic than are the protamins. Whether 

 protamins are toxic in themselves, or whether the toxicity depends on 

 admixtures, is not known for certain. 



In addition to salmin, clupein, scombrin, and sturin, the protamin 

 cyclopterin has been prepared from the spermatozoa of the sea-hare 

 (Cydopterus lumpus) by Morkowin ; 8 the acipenserin, from Acipenser 

 stellatus, by Kurajeff ; 9 two protamins, namely, cyprinin a and ft, from 



1 Mann, Physiological Histology, 1902, p. 102. 



2 D. Kurajeff, Zeitschr. f. physiol. Ghent. 26. 524 (1899). 



3 A. Kossel, ibid. 22. 176 (1896). 



4 A. Kossel and A. Mathews, ibid. 25. 190 (1898). 



5 0. Cohnheim, ibid. 35. 134 (1902). 



6 M. Goto, ibid. 37. 94 (1902X 



7 W. H. Thompson, ibid. 29. 1 (1899). 



8 N. Morkowin, ibid. 28. 313 (1899). 9 D. Kurajeff, ibid. 32. 197 (1901). 



