MECHANISM OF ANTIBODY FORMATION 99 



and coenzyme I no matter how long it may be in contact witK them. 

 Pneumococci do not contain catalase, and are incapable of synthesizing 

 an enzyme no matter how long they remain in contact with catalase or 

 with non-toxic concentrations of hydrogen peroxide as substrate for 

 catalase. Staphylococcus aureus is incapable of synthesizing nico- 

 tinamide and thiamine despite the fact that they are capable of in- 

 corporating them into their metabolic system. 



The assumption of Spiegelman (1946) that there appear endog- 

 enous sources of protein, which are available for transformation into 

 enzyme protein does not therefore appear to be a valid and experi- 

 mentally tenable conception. His assumption also that when a cell is 

 forced to form a new enzyme it may draw upon existent enzymes as a 

 source of protein has been shown to be an impossibility in those bac- 

 terial cells where the required particular enzyme (so-called "adaptable" 

 enzyme protein) is not in existence to start with. The above cited facts 

 as examples of generally occurring events contradict these assump- 

 tions that an organism can synthesize a new enzyme under pressure. 



Under any circumstances, if an adaptive enzyme formation is a 

 reality, it is essential that its characteristics be determined not by an 

 increment in a common type of a metabolic effect, but by unequivocal 

 classical methods of chemistry and immunology. The application of 

 the following two critical tests seems to be essential: 



(1) That there be an absolute qualitative and quantitative differ- 

 ence in the amounts of "galactose apoenzyme" (Spiegelman, 

 Reiner, and Morgan, 1947) in adapted and non-adapted 

 yeasts; and 



(2) That the assumed presence of this adapted galactose apo- 

 enzyme can serologically be demonstrated in the galactose 

 fermenting adapted and not at all in the non-adapted yeast 

 cells. 



The latter method of analysis should particularly be useful in view 

 of the enormous number of experimental facts to show that a- and P- 

 configurations, d- and 1-activity, -COOH and -CONHo, etc. closely 

 related groups present in antigens can be finely differentiated. If the 

 observed increment in the fermentation of galactose is due to a de novo 

 synthesis of a species of an enzyme protein, it should be possible to 

 demonstrate this synthesis in the above mannet. The presence of even 

 a few molecules of this enzyme protein in a non-adapted cell means a 

 genetic provision to synthesize this enzyme. A measurable increment 



