40 



INTRODUCTION TO IMMUNOCHEMICAL SPECIFICITY 



H,NY ^CONHCH.CONHCH.COGH 



/>-Aminobenzoylglycylglycine 



CH3 CH3 



Vh 



I 

 CH2 



I 



H.,n/ \cONHCH2CONHCHCOOH 



/'-Aminobenzoylglycylleucine 

 CH3 CH3 



Yh 



I 



CH, 



1 

 H.n/ \cONHCHCONHCH2COOH 



p-Aminobenzoylleucylglycine 

 Fig. 3-3. 



haptens had an amino acid — COOH at the end, Landsteiner in- 

 terpreted this as showing the predominant influence of the acid- 

 carrying group on specificity. Today we are more incHned to attribute 

 Landsteiner's cross-reactions to the fact that the terminal unit, acid 

 or not, of a composite hapten has greater influence on the specificity 

 than any other group does ; for, as we shall see, a similar rule applies 

 to haptens consisting of oligosaccharides where no acid group is 

 present. 



TABLE 3-1 

 Cross-Reactions of Glycine and Leucine Haptens* 



Landsteiner, 1945. 

 G = glycine, L = leucine. 



