ANTIBODIES AGAINST RESPIRATORY ENZYMES 389 



and Miller (1948) to determine the effect of the specific sera with and 

 without complement on the oxygen consumption by E. ty'phosa and 

 pneumococcal cells. As is known, sensitized E. typhosa cells are lyzed 

 by the action of complement, and pneumococcus is resistant to this 

 action. A quantitative method was developed to determine the weight 

 of bacteria present in agglutinated clumps, and also the weight of 

 bacteria which had undergone lysis during the aerobic oxidation of 

 glucose and glycerol in the presence of immune sera and complement. 

 This method enabled us to determine the percentage of lysis of the 

 cells at various periods during metabolic studies. 



Calculating QO2 (mm^Oo/mg. cells/hour) values in this manner, it 

 was found that agglutinated E. typhosa (strains O-901 and H-901) 

 and pneumococci consume volumes of oxygen equal to those of the 

 respective controls. Intact sensitized cells with or without complement 

 do not experience loss of oxidative activity, indicating that the forma- 

 tion of agglutinated clumps does not involve physical or immunological 

 barriers to the activity of oxidative enzymes. In other words, substrates 

 such as glucose and glycerol and oxygen can permeate between the 

 antibody molecules deposited on the cell-walls of bacteria. 



Sensitized E. typhosa (O-901) cells acted upon by complement 

 undergo lysis. Immediately after lysis considerably more oxygen is 

 used than by the controls containing the intact cells. Subsequently, 

 the oxygen consumption of the lysed system undergoes up to 88 per 

 cent reduction. Whether or not the previously mentioned reduction 

 in oxygen uptake by the lysed fractions of bacilli obtained by the 

 action of complement on sensitized cells is due to the deterioration of 

 liberated enzyme systems or to an inhibitory effect of a specific com- 

 bination between liberated intact oxidative respiratory enzymes and 

 homologous antibodies cannot at present be answered. 



In a similar study, Harris (1948) reported that oxygen uptake, with 

 glucose as the substrate, by eight species of Salmonella occurred at 

 essentially the same rate when the cells were in the presence of fresh 

 immune rabbit serum as when in fresh normal serum. Using Thunberg 

 technique for dehydrogenase activity, likewise the reduction of 

 methylene blue occurred at the same ratio in both immune and normal 

 serum. 



In this connection it must be remembered that due to the large size 

 of the antibody molecules, a combination between the oxidative 



