MECHANISM OF ANTIBODY FORMATION 125 



sera. The precipitation of these antigens in Type III immune horse sera 

 was inhibited indiscriminately by the sodium salt of any one of the 

 uncombined acidic derivatives (p-aminobenzene sulfonic acid, |7-ami- 

 nobenzene carboxylic acid, p-aminobenzylglucuronide, |9-aminobenzyl- 

 galacturonide as inhibiting substances against the test antigens 

 prepared from them and chick serum). 



The above cited substances containing — COOH and — SO3H 

 groups, possess but one property in common, namely, acidic groups of 

 divergent nature. As stated by Goebel and Hotchldss the reaction of 

 these antigens in antipneumococcal horse sera represents a neutraliza- 

 tion of the charge of basic groups of the antibody protein by the acid 

 groups of the non-specific haptens, followed by precipitation. 



b. The Directive Influence of Optically Active Catalysts in 

 Producing Optically Active Substances. The presence of serologi- 

 cally reactive basic amino groups in antibody globulin may appear to 

 indicate that during its synthesis the position of the basic — NH2 

 groups had been specifically oriented by the presence of -COOH polar 

 groups of the pneumococcal carbohydrate, or synthetic glucoproteins. 

 In contrast, during the synthesis of normal globulin, the position of the 

 amino groups not being directed by foreign influences, do not occupy 

 any specific position with reference to foreign substances. 



It can be visualized that, similar to the orienting influence of 

 — COOH groups in the pneumococcal carbohydrates, optically active 

 groups in d- and 1-antigens (Landsteiner and van der Scheer, 1928, 

 1929) may specifically orient certain groups during the synthesis of the 

 antibody globulin molecule to conform with the optical configuration 

 of the antigens. The question as to whether d- and 1-antigens, acting 

 as optically active catalysts, have produced optically active specific 

 groups in the antibody molecule is of general interest; to this question 

 we have at present, no direct answer. It has been observed by numer- 

 ous investigators that in general, it is characteristic of living cells to 

 metabolize or synthesize only one mirror image of optically active 

 substances. This fact has been known since the time of Pasteur and 

 the literature is rich in confirmatory evidence which we need not dis- 

 cuss here. 



In relation to the question raised above whether optically active 

 antigens produce antibodies with specifically oriented optically ac- 

 tive groups responsible for the serological reactivity, it might likewise 



