LECITHALBUMINS. 105 



and are readily soluble in dilute salt solutions. The behavior of the 

 nucleoalbumin of the eggs of the perch shows how easily this solubility 

 may be changed. This nucleoalbumin, which contains considerable 

 amounts of lecithin, is readily soluble in dilute NaCl solution, but at 

 ordinary temperatures it is changed by 0.1 per cent HC1 nearly instanta- 

 neously and without splitting off lecithin, so that it becomes insoluble 

 in dilute salt solutions (HAMMARSTEN). LIEBERMANN 1 has obtained 

 proteids containing lecithin as an insoluble residue on the peptic digestion 

 of the mucous membrane of the stomach, liver, kidneys, lungs, and spleen. 

 He considers them as combinations of proteid and lecithin and calls them 

 lecithaibumins. Further investigation of these bodies is desirable. 



MAYER and TERROINE 2 have shown that from lecithin emulsified in water and 

 a dialyzed solution of ovalbumin or dialyzed blood serum a precipitate can be 

 obtained which has some similarity to the lecithaibumins, but which in other 

 respects is so strikingly different that we are not justified in calling this pre- 

 cipitate lecithalbumin. 



Nothing characteristic has thus far been found which differentiates 

 this group from others in the quantity of amino-acids split off on hydrol- 

 ysis. The members of this group differ essentially among themselves, 

 e.g., vitellin yields glycocoll while casein does not. 



In order to give a review of the three above-mentioned groups of pro- 

 teids we give (page 106) a tabulation of the amounts of the amino-acids 

 obtained on cleavage, but we must bear in mind that the figures, because 

 of the difficulty in the quantitative estimation, are not quite exact, but 

 must be considered as minimum values. As a representative of the glob- 

 ulin group we give fibrin, which is a coagulated globulin; and as repre- 

 sentative of the phosphoprotein group, ovovitellin, although not quite 

 pure. The results are based on 100 parts of the substance. 



The proteins occurring in the plant kingdom correspond in part to 

 the above-described three groups of animal proteids. Among these the 

 globulins are especially represented, and as an example we will specially 

 mention the crystalline edestin, occurring in the hemp-seed. It is not 

 clear whether the phosphorized plant proteids contain their phosphorus 

 as impurities or whether they are the same as the animal phospho- 

 proteins. There is no doubt that certain vegetable proteids cannot 

 be classified in the above groups, namely, gliadin of the wheat and zein 

 of the corn kernel, which are proteins soluble in alcohol. They are also 

 characterized by not yielding any lysine. 



1 Hoppe-Seyler, Med. chem. Untersuch., 1868; also Zeitschr. f. physiol. Chem., 13, 

 479; Hammarsten, Skand. Arch. f. Physiol., 17; Liebermann, Pfliiger's Archiv, 50 

 .and 54. 



2 Compt. rend. soc. biol., 62. 



