412 



BACTERIOLOGICAL CHEMISTRY 



was diazotisecl and coupled with proteiiLS, it aLsu produced 

 specific antigens in which the glucose molecule acted as 

 the determinant group, but marked cross -reactions took 

 place l)etween the a- and ^-giucoside antigen-antiserum 

 pairs. It thus appears again that the terminal group, 

 — CHOH, at position 4 in these cases, has a greater effect 

 than groups situated within the molecule, such as the 

 a- and ^-glucoside links in these examples. 



Artificial antigens containing glucuronic or galac- 

 turonic acids as determinants react with various anti- 

 pneumococcal horse sera, but their injection into animals 

 does not provoke antibodies which protect the animal 

 against iniection with pneumococci. If, however, an 

 antigen made by coupling synthetic, diazotised 2?-amino- 

 benzyl cellobiuronide (6- jS-glucuronosidoglucose), 



H 



OH 



HO 



H 



H 



OH H 

 H 



COOH 



-CHj 



I 



Os 



H A 



l/H 



|\ OH H 

 OH 



-CH2.C6H4.NH2 



H 



OH 



with horse serum globulin is injected, antibodies are 

 formed which give precipitin reactions with the Type III 

 polysaccharide, agglutinate Type III pneumococci and 

 confer on mice passive immunity against virulent Types 

 II, III and VIII pneumococci. The corresponding 

 antigen containing gentiobiuronic acid (4- ^-glucuronosido- 

 glucose). 



H 



OH 



HO 



CH2OH 



J 



/ \ H H /. 



OH H \| l/H 



H / n l\^^ " 



CHo.CeH^.NH. 



COOH H OH 



gives rise to antisera which have no protective effect in 



