64 GENERAL AND PHYSICO-CHEMICAL. 



tion. HILDEBRANDT 1 first produced an anti-enzyme toward emulsin; 

 and MORGENROTH 2 obtained in a similar manner an anti-rennin in goats' 

 serum; BORDET and GENGOU 3 immunized against fibrin ferment, SACHS' 4 

 against pepsin, SCHUTZE as well as BERTARELLI 5 against various 

 plant lipases, SCHUTZE 6 against lactase, PRETI as well as SCHUTZE and 

 BRAUN 7 against diastase, K. MEYER 8 against the proteases of bacillus 

 prodigiosus and bacillus pyocyaneus. 



2. The retarding body of the rennin enzyme which was obtained 

 by treating a neutral infusion of the mucous membrane with dilute 

 ammonia and neutralizing, has been recently shown by HEDiN 9 to 

 chiefly retard the enzyme of the same species (see Chapter VIII). In 

 these cases the importance of the order of treatment was also evident. 



Most of the retarding substances contained in the serum lose their 

 retarding power on sufficiently heating them. This also occurs in cer- 

 tain cases by treatment with acid. Thus normal horse serum as 

 well as egg-white lose their ability to retard rennin by treatment 

 with very dilute hydrochloric acid and for this reason rennin which 

 has been inactivated by serum or egg-white can be set free again 

 by the use of hydrochloric acid (HEDIN) 10 . Native seralbumin loses 

 its power of attaching itself to trypsin by treatment with dilute 

 acetic acid. 



Certain proteins which are digested with difficulty retard the diges- 

 tion of more readily digestible ones without the order-phenomenon being 

 observed. In such cases the total digestion is probably diminished 

 because the more difficultly digested protein as substrate attracts a 

 part of the enzyme. As the order-phenomenon does not exist, the enzyme 

 is taken up in a complete and readily reversible manner (enzyme devia- 

 tion HEDiN). 11 It is easily understood that the retardation must be 

 less effective than in those cases where the enzyme is attached to the 

 retarding substance. The tryptic digestion of casein in the presence 

 of seralbumin, treated with acid, is diminished by enzyme deviation as 

 well as the digestion of readily split proteins is retarded by egg-white 



1 Virchow's Arch., 131, 33 (1893). 



2 Centralbl. f. Bakt., 26, 349 (1899); 27, 357 (1900). 



3 Ann. inst. Past. 15, 129 (1901). 



4 Fortschr. d. Med., 20, 593 (1901). 



5 Deutsch. med. Wochenschr., 1904; Centralbl. f. Bakt., 40, 231 (1905). 



6 Zeitschr. f. Hyg., 48, 457 (1904). 



7 Bioch. Zeitschr., 4, 6 (1907); Zeitschr. exp. Pathol. u. Therap., 6, 307 (1909). 

 Bioch. Zeitschr., 32, 280 (1911). 



Zeitschr. f. physiol. Chem., 72, 187; 74, 242; 76, 355 (1911). 

 Zeitschr. f. physiol. Chem., 60, 85, 364 (1909). 

 a., 52, 412(1907). 



