ANTI-ENZYME IMMUNITY 213 



when the enzyme is free for combination with the specific antibody. 

 Such combinations being comparatively non-dissociable, the concen- 

 tration of the enzyme would be markedly reduced, in other words, one 

 should notice measurable decrease in the degree of enzyme activity. 

 Since, in experiments where the enzyme and the substrate are first 

 brought together, such decreases in activity are not observed, it would 

 seem that the affinity between the enzyme and substrate is far greater 

 than that of the enzyme and the antibody. A somewhat different pic- 

 ture is gained from the results of Housewright and Henry (1947) 

 obtained from a study of penicillinase-penicillin-antipenicillinase inter- 

 actions (see p. 332). In this, as in the lecithinase studies, the substrate 

 penicillin was incapable of displacing the specific inhibitor, antipeni- 

 cillinase, from its combination with penicillinase. On the other hand, 

 penicillinase which had been in contact with penicillin showed affinity 

 for antipenicillinase which was twice as great as that shown for peni- 

 cillin. 



C. ANTIBODY AGAINST CARBOHYDRASES 



A review of the studies on immune reactions reveals that in the 

 earlier period of the development of the science of immunology investi- 

 gators held the point of view that enzymes played an important role 

 in the pathogenesis of infectious diseases. They may have thought in 

 the inner recesses of their minds that immunity against infectious 

 diseases might in some way be related to anti-enzyme immunity. It is 

 perhaps for this reason that among earlier immunological studies there 

 are numerous reports on the subject of anti-enzyme immunity. While 

 methods for the study of toxin-antitoxin, venom-antivenom reactions, 

 and those pertaining to the study of various phases of anti-bacterial 

 and anti-hemolytic immunity have been developed and perfected, the 

 development of reliable methods of preparing enzymes for similar 

 studies has been progressing at a slower rate. The more subtle nature 

 of the enzymes and the ease with which their activity is reduced or 

 abolished may have contributed in part to this slow progress. Despite 

 these shortcomings, a beginning was made as early as 1893 when Hil- 

 debrandt reported the first study of its kind on the formation of anti- 

 body against emulsin. We will therefore begin with the description 

 of the study of this early investigator. 



