422 CHEMISTRY OF THE PROTEIDS CHAP. 



Kossel and Dakin 1 deny the presence of alanin and of leucin, which 

 two mono-amino acids were obtained by Abderhalden, 2 who examined 

 salmin by Emil Fischer's ester-method. Abderhalden thought to have 

 obtained, in all probability, also phenylalanin and aspartic acid. It 

 is suggested by Kossel and Dakin that Abderhalden probably worked 

 with immature testicles. 



The protamin of the Californian salmon is, according to Taylor, 3 

 identical with that of the European variety. He found salmin-sulphate 

 to diffuse very slowly through parchment paper ; to be markedly 

 dissociated in watery solutions, a half per cent solution giving 60 x 10. 

 The laevo-rotation produced by a saturated solution is - 6. The 

 watery solution undergoes 'spontaneously' a hydrolytic change, and 

 it is suggested that salmin should be used for experiments on such 

 ferments as trypsin. 



As will be seen from Kossel's table on p. 420, protamins contain 

 a certain amount of mono-amino acids, and therefore a sharp line of 

 demarcation between the protamins and the other albumins no longer 

 exists, especially as the histones form both genetically and chemically 

 the transition to the true albumins. Protamins must therefore be 

 classed amongst the albumins. They form a special group which, 

 owing to the absence of certain radicals, does not give the reactions 

 common to most of the albumins, but in this respect they are analogous 

 to gelatine or hetero-albumose, which contain neither tyrosin nor 

 tryptophane, or to casein or globin in which glycocoll is absent. 

 Salmin, with its rich store of di-amino-acids, forms one end of a chain, 

 the other end of which is represented by serin, which contains hardly 

 any di-amino-acids (Cohnheim). 



Protamins differ from ordinary albumins in not being coagulated 

 by heat. On standing they undergo a change, which points to a kind 

 of denaturalisation. The protamins resemble the histones in being 

 precipitated by alkaloidal reagents not only from acid, but also from 

 neutral solutions, but as the protamins are stronger bases than are 

 the histones, they are even precipitated from alkaline solutions, the 

 serial arrangement, albumin -> histone -> protamin, in this connection 

 being very evident. Protamins are therefore precipitated by the alkali- 

 tungstates and phospho-tungstates, by ferro- and ferri-cyanide, iodine 

 potassium iodide, iodide of mercury + iodide of potash, alkali picrates, 

 corrosive sublimate, mercuric nitrate, platinum chloride, gold chloride, 



1 A. Kossel and H. D. Dakin, Zeitschr. f. physiol. C/iem. 41. 407 (1904). 



2 Emil Abderhalden, Zeitschr. f. physiol. Chem. 41. 55 (1904). 



3 A. E. Taylor, Univ. of California public. Path. 1. p. 49. Abstract by Alsberg 

 Boston) in ZentralU.f. Physiol. 18. 631 (1904). 



