The Journal of biological chemistry . or Preparation 1 becomes flat TABLE v. Nitrogen of the Basic Amino-Acids in 100 Gm. of Gliadin and in Gm. of Preparation 1 Obtained from 100 Gm. of Gliadin. Gliadin. Preparation 1. Total N gm. Arginine N Histidine N Lysine N TABLE VI. Rate of Hydrolysis of Preparation 1 by 2 n Hydrochloric Acid. Time. Total N as amino N. Total peptidp N asfree amino N. firs. per cent per cent 0 1 4 10 12 20 24 34 45 76 88 af
The Journal of biological chemistry . or Preparation 1 becomes flat TABLE v. Nitrogen of the Basic Amino-Acids in 100 Gm. of Gliadin and in Gm. of Preparation 1 Obtained from 100 Gm. of Gliadin. Gliadin. Preparation 1. Total N gm. Arginine N Histidine N Lysine N TABLE VI. Rate of Hydrolysis of Preparation 1 by 2 n Hydrochloric Acid. Time. Total N as amino N. Total peptidp N asfree amino N. firs. per cent per cent 0 1 4 10 12 20 24 34 45 76 88 after 45 hours, at which time 88 per cent of the bonds are broken,and subsequently rises very slightly. It seems probable, there-fore, that Preparation 1 yields, on long hydrolysis with 2 n hy-drochloric acid, a mixture containing relatively stable but simplepeptides. In view of Osborne and Clapps (1907) experiencewith the exceedingly stable dipeptide of proline and phenylala-nine from gliadin, this is not surprising. H. B. Vickery 425. o o o in -^ <^ THE JOURNAL OF BIOLOGICAL CHEMISTRY, VOL. LVI, NO. 2 426 Mild Acid Hydrolysis of Wheat Gliadin The gradual evolution of ammonia, probablj^ due to deamina-tion, is also well shown by the data. With respect to its content of arginine, lysine, and the non-amino nitrogen of the filtrate from the basic amino-acids, whichis probably very largely proline nitrogen, the insoluble productobtained when gliadin is hydrolyzed with dilute acid at boilingtemperature differs in constitution from that calculated for gliadinfrom which amide nitrogen alone has been removed. Moreover,when prepared under the conditions detailed above, this insolublefraction contains all the lysine of the original gliadin. In itsproduction, therefore, hydrolysis of peptide bindings as well asof amide bindings has played a part. Efforts to remove onlyamide nitrogen from gliadin, without simultaneously rupturingpeptide bonds, have been unsuccessful. The rate at which ab
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