ANTI-ENZYME IMMUNITY 



333 



stated to be essential for enzymatic activity. It was found to he fairly 

 resistant to oxidation but susceptible to reduction. The pH optimum 

 of penicillinase at 36° was found to be approximately 7.2. It manifested 

 a high degree of specificity for the configuration of the basic penicillin 

 molecules. Penicillinase had no action on xanthine, adenine sulfate, 

 guanine, riboflavin and uracil. These substances contain the configura- 

 tion which is present also in penicillin. The action of penicillinase on 

 penicillin results in the formation of a carboxyl group from the carbonyl 

 group which is adjacent to the ring nitrogen. The carboxyl group 

 which is formed reacts with bicarbonate liberating carbon dioxide 

 which is measured manometrically. 



R 



= C— N— CH— C 

 H 



C(CH3)2 



C N CHCOONa 



II 



O + Penicillinase 



Y 



R S 



= C— N CH— C C(CH3)2 



-CHCOONa 



H 



HOOC N 



H 



Perlstein and Liebman (1945) reported that 4000 units of penicillin 

 were protected by antipenicillinase immune serum from inactivation 

 by as high as 100 units of penicillinase. In the control series with 

 normal serum or saline only 25 units of penicillinase were sufficient to 

 inactivate 4000 units of penicillin in one hour at 37°C. They postu- 

 lated the formation of a penicillin-plasma protein complex which 

 protects penicillin in vitro from destruction by penicillinase. 



Housewright and Henry (1947) remarked that such a postulate is 

 not necessary since simple combination of penicillinase and antipenicil- 

 linase (antibody) should prevent destruction of penicillin, which is in 

 accord with our view. 



Housewright and Henry ( 1 947b) immunized rabbits with dialyzed 



