MECHANISM OF ANTIBODY FORMATION 123 



definitive influence on the serological specificity of the antibodies 

 produced. 



The optical antipodes, as well as space isomers differ chemically 

 and physicochemically, exercising different degrees of attractive and 

 repulsive forces. Atoms or atomic groups falling within the influ- 

 ence of these forces are either repulsed out of the sphere of influence 

 or are attracted to combine. The optical and space isomers thus mani- 

 fest different properties in combining with proteins, functioning as a 

 substrate for an enzyme, in bacteriostatic action, in enzyme inhibiting 

 effect, in forming racemates, etc. During the synthesis of globulin 

 molecules under the influence of antigens containing polar groups, or 

 optical and space isomers, such influences do, no doubt, come into 

 play. It could thus be assumed that during the synthesis of the globu- 

 lin molecules the atomic groups rotate their position in space in ac- 

 cordance with the configuration of the antigenic molecule, resulting 

 in the formation of antibody as modified globulin. 



a. Presence of Serologically Reactive Basic Amino Groups in 

 Antibody Globulins. Mudd and Joffe (1933) found that when 

 antisera were treated with formaldehyde before combination with anti- 

 gen, agglutination was consistently inhibited. The antibodies treated 

 with formaldehyde showed decreased basicity, which was evidenced by 

 a shift in the isoelectric point of the sensitizing film toward the acid side 

 by about 0.6 to 0.8 pH unit, and reduced agglutinating tendency of the 

 sensitizing film. Chow and Goebel (1935) investigated chemically and 

 serologically the function of the basic amino groups in Type I anti- 

 pneumococcus precipitin. Eighty-eight per cent of the purified anti- 

 body they studied was precipitable by Type I specific carbohydrate. The 

 remaining 12 per cent protein was considered as representing anti- 

 bodies against cellular proteins of the pneumococcus and for the 

 somatic carbohydrate present in the original serum. The isoelectric 

 point of the precipitin was unusually alkaline, i.e., pH 7.6. This was 

 attributed to the presence of either a relatively high ratio of amino to 

 carboxyl groups or to the presence of a higher percentage of basic 

 amino acids in the antibody molecule than the globulin of normal 

 serum would contain. The distribution of basic amino acids in the 

 globulin of normal and immune horse serum, aside from a slightly 

 higher lysine content of the latter, showed no essential difference. 

 Acetylation of antibody revealed the presence of one acetyl group for 



