SUMMARY. 



113 



The following products of hydrolysis have been obtained by boiling 

 glutenin with strong hydrochloric acid : 



Products of hydrolysis of glutenin. 



P.ct. 



Glycocoll 0.89 



Alanine 4-65 



Amino-valerianic acid 0.24 



Leucine 5.95 



^-proline 4.23 



Phenylalanine 1.97 



Aspartic acid 0.91 



Glutaminic acid 23.42 



Serine 0.74 



P.ct. 



Tyrosine ... 4.25 



Cystine 0.02 



Lysine 1.92 



Histidine 1.76 



Arginine 4.72 



Ammonia 4- nI 



Tryptophane present 



59.66 



Glutenin is qualitatively distinguished from gliadin by yielding both 

 glycocoll and lysine, and quantitatively by yielding less proline, glutaminic 

 acid, and ammonia and more alanine, tyrosine, and arginine. In other 

 respects the differences are not great. 



The amount of glutenin varies greatly in different samples of wheats, but 

 usually forms about 40 per cent of the total protein of the seed. Teller has 

 found in a sample of Canadian white winter wheat 3.64 per cent of glutenin and 

 in an Oregon white winter wheat 3.82 per cent, while in a red spring wheat 

 from South Dakota he found 8.04 per cent. Although the total amount of 

 glutenin in these wheats was very different, the relative amounts were nearly 

 the same, being 45.2 and 46.5 percent of the total proteins in the white 

 winter wheats and 42 per cent in the red spring wheat. Other winter 

 wheats differed but little from other spring wheats both in the total and 

 relative amount of glutenin which they contained. In most of the wheats 

 that he examined the glutein formed from 40 to 45 per cent of the total 

 proteins. Shepard, who analyzed a much larger number of samples, found 

 a wider variation in the relative proportion of glutenin, from 34.2 to 46.8 

 per cent of the total proteins, and a narrower range in its total amount, the 

 latter falling between 3.41 and 7. 10 per cent. 



LEUCOSIN. 



Leucosin forms about 0.3 to 0.4 per cent of the wheat kernel. Although 

 the entire seed contains but little leucosin, the embryo contains a relatively 

 large proportion, since about 10 per cent of the commercial " germ meal " 

 consists of this protein. As this ' ' germ meal ' ' contains more or less of the 

 endosperm and outer coats of the seed, the embryo contains somewhat more 

 than 10 per cent. Leucosin is an albumin, for it is soluble in pure water 

 and coagulated by heating its solution. It has been mistaken by several 

 observers for a myosin-like globulin, owing to the fact that its temperature 

 of coagulation falls near to that of such globulins found in animal tissues, 

 8 



