82 TISSUE FERMENTS 



of autolytic cleavage of tissue proteids there occurs a much 

 more marked production of ammonia (presumably from the 

 non-fixed nitrogen which is split off as ammonia by hy- 

 drolysis) than in acid hydrolysis. Thereafter Sigmund 

 Lang 19 in the same laboratory determined the autolytic 

 separation of ammonia both from acid amides (as asparagin, 

 COOH CH 2 CH.NH 2 CONH 2 , and glutamin) and from 

 aminoacids. It is now recognized that deamidization of the 

 first of these series takes place very readily in alkali- 

 hydrolysis according to the schema : E.CONH 2 + H 2 = 

 E.COOH + NH 3 . The author has not failed to obtain this 

 result in any of his studies, conducted in association with 

 M. Friedmann, in quantitative comparisons of autolytic 

 asparagin cleavage in various animal tissues. 20 The fre- 

 quent occurrence of amide-cleaving ferments in vegetable 

 tissues, which are rich in acid amides, has been fully estab- 

 lished by a number of investigators. 21 Of more interest than 

 this group of enzymes are the deamidases, which are capable 

 of splitting off from an aminoacid its firmly attached nitro- 

 gen, which successfully resists the cleaving power of boiling 

 fuming hydrochloric acid. Just as yeasts or moulds 

 can split ammonia from aminoacids and transform 

 them into oxy-fatty acids 22 (according to the schema: 

 B.NH 2 B.OHK 



' S precisely the same 



changes can apparently take place in autolysis of animal 

 tissues. 23 Cohnheim has observed a demidization of this 

 sort in the passage of aminoacids through the living intes- 



19 S'. Lang (F. Hofmeister's Lab., Strassburg), Hofmeister's Beitrage, 5, 

 320, 1904. 



20 O. v. Fiirth and M. Friedmann, Biochem. Zeitschr., 26, 435, 1910. 



21 K. Shibata, N. Castoro, H. Pringsheim, W. Butkewitsch, A. Kiesel. 

 Literature: O. v. Fiirth and M. Friedmann, 1. c. 



22 H. Pringsheim, Biochem. Zeitschr., 12, 15, 1908. 



98 S. Lang, 1. c., 0. Schumm, Hofmeister's Beitr., 7, 175, 1906; F. Simon 

 (Salkowski's Lab.), Zeitschr. f. physiol. Chem., 70, 65, 1910; W. Lindemann 

 (Physiol. Instit., Halle), Zeitschr. f. BioL, 55, 36, 1910. 



