RESEMBLANCES OF ENZYMES AND TOXINS G7 



least ill somo respects different from one another, since they are com- 

 bined by different antibodies. Apparently that element of the en- 

 zymes which detei-mines their action on specific substances is involved 

 in their antigenic properties, since antiproteases will not inhibit dias- 

 tase or lipase. This specificity is limited, however, for the anti-en- 

 zymes for leucocytic and pancreatic proteases are said to be iden- 

 tical.^* Artificial immune serum is said to have been obtained aj^ainst 

 trypsin, pepsin.^* lipase, emulsin,''^ autolytic enzymes, laccase, amyl- 

 ase, invertin, diastase, tyrosinase, urease, '^"'^ rennin, catalase, and 

 fibrin ferment.*'* By immunization against bacteria an immunity 

 against their proteolytic enzymes is also obtained,"^ which is inde- 

 pendent of and different from antitrypsin, being especially in the 

 globulin fraction, while the antibody for pancreatic trypsin is chiefly 

 in the albumin (Kammerer ''^). From the work of Kirchheim and 

 Reinicke *^-^ it seems probable that the increased resistance following 

 immunization with trypsin is simply an increase in nonspecific resist- 

 ance, such as follows injection of peptone and many other poisonous 

 substances. There is, indeed, a growing suspicion that much of the 

 evidence of specific antibody formation for enzymes must be revised. 

 Resemblances of Enzymes and Toxins. — As can be seen from the 

 above statements, the enzymes behave in many respects like the tox- 

 ins, both in their manner of acting upon other substances and in the 

 reaction they produce when introduced into the bodies of animals. 

 As Oppenheimer says, "the bonds between enzymes and toxins are 

 drawing closer and closer." According to some experiments, the 

 enzymes behave much as if they possessed a haptophore and a toxo- 

 phore group, the former of which combines with the substance that is 

 to be acted upon; and immunity appears to be produced by the de- 

 velopment of receptors that combine the haptophore groups, these 

 receptors constituting the antiferments. There is abundant evidence 

 of a toxin-like structure in enzymes, from the numerous observations 

 on the formation of "zymoids" which can neutralize anti-enzymes or 

 combine with the substrate, although no longer active as enzymes. 

 The oxidizing enzymes especially, with their complex relationship of 

 substrate, combining body (peroxides) and enzyme, present striking 



64 .Jochmann and Kantorowiez, IMiinch. med. Wocli., 1908. (5.5), 728. 



65 Bayliss (.Tour, of Physiol., 1912 (4-3), 455) was unable to obtain anti- 

 emulsin, and Pozerski (Ann. Inst. Pasteur, 1909 (2.3), 20.")) failed to ol)tain anti- 

 papain, but positive results are reported bv v. Stenitzer (Biochem. Zeit.. 1908 (9), 

 382). 



63a .Tacoby says that the disappearance of mease from the blood after repeated 

 injection does not depend on the formation of an anticnzvme (Biochem. Zeit., 

 1916 (74), 97). 



66 For a review of mucli of the earlier literature on this subject see Schiitze, 

 Deut, med. Woch., 1904 (30), 308. 



6" V. Dunpern, ^Fiinch. med. Wochenschr., 1898 (45), 1040; Bertiau, Cent. f. 

 Bact., 1914 (74), 374. 



68 Deut. Arch. klin. Med.. 1911 (103). 341. 

 68a Arch. exp. Path., 1914 (77), 412. 



