226 IMMUNO-CATALYSIS 



1940; Reeves and Goebel, 1941; Stacey, 1946; Evans & Hibbert, 

 1946), These polysaccharides as components of conjugated antigens 

 are responsible for the serological type-specificities of forty or more 

 types of pneumococci. The composition of each polysaccharide is 

 unique for each type. Cross reactions among certain pneumococcal 

 types would indicate structural relationship of their polysaccharides. 



Polysaccharide of type 1 pneumococcus has been found to contain 

 D-galacturonic acid, amino sugar and acetyl residues; type 2, glucose, 

 aldobionic acid and uronic anhydride; type 3, cellobiuronic acid units, 

 and; type 4, D-glucose and N-acetyl-hexosamine. The species specific 

 polysaccharide "C" of the rough pneumococcus has been found to con- 

 tain N-acetyl-D-glucosamine, a hexose and phosphoric acid. It has 

 further been shown that type 14 polysaccharide possesses chemical and 

 serological relationship to the polysaccharides of human erythrocytes 

 of types A, B, AB and O (Goebel, et al, 1939). Blood group A 

 carbohydrate has been shown (Bray, et al., 1944) to contain units of 

 D-mannose, D-galactose, N-acetyl-D-glucosamine, and L-fucose. 



It has been suggested that polysaccharides are integral components 

 of physiologically active animal proteins such as hormones (Gurin, 

 1942, 1944; Stacey, 1946). For maximal hormonal activity the in- 

 tactness of polysaccharide and protein fragments are held necessary. 

 Gurin (1942) reported that the luteinizing and follicle-stimulating 

 hormones prepared from the pituitary gland contain mannose and 

 hexosamine in equimolar proportions. The gonadotropins of pregnant 

 mare serum and human pregnancy urine appear to contain galactose 

 rather than mannose. In these preparations the molar ratio of hexose 

 to hexosamine was 2:1. 



There is practically no information concerning the mechanism of the 

 in vivo synthesis of above cited bacterial and animal carbohydrates. 

 However, considerable advances have been made during recent years in 

 the understanding of certain phases of in vitro enzymatic synthesis of 

 mammalian (blood group polysaccharide), plant and certain bacterial 

 polysaccharides. Of these, only the plant or mammalian starches, 

 glycogen have been shown not to possess immunological properties. 

 This is understandable in view of the fact that there does not appear 

 to exist any configurational or structural difference among the starches 

 and glycogens from various sources, and therefore they are not foreign 

 to the animal host used for immunization purposes. 



