296 PROTEIN POISONS 



and lysin). The precipitate with phosphomolybdic acid 

 may be crystallized, and the picrate differs from the corre- 

 sponding salts of arginin and lysin by its solubility in alcohol. 

 The kyrins give the biuret reaction, the color differing 

 from that given by peptone in being more distinctly a 

 Bordeaux red. Siegfried states that the kyrin formed 

 from fibrin splits on further cleavage into lysin, arginin, 

 and glutamic acid. 



The kyrins are said to be highly poisonous, and Kam- 

 mann 1 has suggested that they, or similar bodies, may be 

 the active agents in the production of anaphylactic shock. 

 However, we have been unable to find any record of thor- 

 ough studies of the poisonous action of these cleavage 

 products. Schittenhelm and Weichardt 2 have studied 

 two kyrins, one prepared from hemoglobin and the other 

 from gelatin. The latter is not poisonous, and this agrees 

 with our work in which we failed to obtain the poisonous 

 group from gelatin. The globinokyrin is moderately 

 active, but not so poisonous as the protamins. 



Anaphylatoxin. Friedberger 3 treated rabbits with lambs' 

 serum until he obtained abundant precipitates with the sera 

 of these animals. These precipitates were deposited in 

 a centrifuge, washed with salt solution, and then digested 

 with normal guinea-pig serum for some hours in the incu- 

 bator. When this was done and the serum decanted and 

 injected into normal guinea-pigs, the animals promptly 

 died with all the symptoms of anaphylactic shock. A 

 poison had already been obtained in a similar manner by 

 Weichardt from placental tissue, and by Friedemann from 

 blood corpuscles (see p. 269). Friedberger named the poison- 

 ous substance which he obtained by the digestion of specific 

 precipitates with normal serum, anaphylatoxin. Desig- 

 nating this substance as a toxin might be criticized, but 

 at that time Friedberger believed in his theory of sessile 

 receptors, and it is plain that he regarded the poison which 



1 Zeitsch. f. Immunitatsforschung, 1911, xi, 659. 



2 Ibid., 1912, xiv, 609. 3 Ibid., 1910, iv, 636. 



