74 ENZYMES 



serum is in the pseudoglobulin fraction. Since acids destroy 

 the anti-enzyme property of the serum, it is not effective against 

 pepsin-HCl mixtures. Against trypsin, however, it is very 

 effective. Red corpuscles and living unicellular organisms are 

 likewise resistant to trypsin, and normal serum also seems to 

 contain an antirennin. l 



Oppenheimer and Aron 2 consider it probable that the resist 

 tance of normal serum to trypsin digestion depends upon the 

 configuration of the proteid molecules, which perhaps, when in 

 fresh, uninjured condition, present no suitable surfaces for 

 attack by the ferment. 



Opie 3 has found that the serum of inflammatory exudates 

 contains an anti-enzymatic substance, destroyed at 75, and by 

 acids. 



Ascoli and Bezzola 4 state that the antitryptic action of the 

 blood is increased during pneumonia, which is probably the 

 result of a self-immunization against the ferments liberated by 

 the disintegrated leucocytes. 5 



The anti-enzymatic property obtained in the serum by inject- 

 ing enzymes into animals differs from that normally present in 

 the serum in many ways. It may be made much stronger 

 than it ever is in normal serum, and against many varieties of 

 enzymes for which an anti-enzyme does not naturally exist. 

 Especially important is the fact that it is highly specific (v. 

 Eisler) ; serum of an animal immunized against dog trypsin 

 will show a much greater effect against dog trypsin than it does 

 against trypsin from other animals. This fact permits us to 

 distinguish between enzymes of apparently similar nature but 

 of different origin, and proves that they have a structure at 

 least in some respects different from one another, since they are 

 combined by different antibodies. Artificial immune serum 

 has been obtained against trypsin, pepsin, lipase, emulsin, auto- 

 lytic enzymes, tyrosinase, urease, rennin, catalase, and fibrin fer- 

 ment. 6 By immunization against bacteria an immunity against 

 their proteolytic enzymes is also obtained/ 



1 Czapek (Ber. Deut. botan. Gesell., 1903 (21), 229, states that anti-oxidases 

 occur normally in certain plants, strongly specific against the oxidase of the 

 same plant species. 



2 Hofrneister's Beitrage, 1903 (4), 279. 



3 Jour. Exp. Med., 1905 (7), 316. 



4 Berl. klin. Woch., 1903 (40), 391. 



5 Beitzke and Neuberg ( Virch. Arch., 1906 (183), 169) have suggested 

 that anti-enzymes may act by causing a synthesis that opposes the catalysis of 

 the enzyme. 



6 For a review of much of the literature on this subject see Schiitze, Deut. 

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



7 v. Dungern, Munch, med. Wochenschr., 1898 (45), 1040. 



