46 EGG AND SPERM SUBSTANCES 



Table III. Monosaccharides Identified in Hydrolyzatcs of 

 Sea Urchin Fertilizins 



So far fertilizin has not been separated into polysaccharide and 

 protein moieties, at least under mild conditions. Upon oxidation 

 of Echinocardium fertilizin with periodate, Vassem* ( 1952b ) 

 obtained a precipitate. Analysis of the precipitate and supernatant 

 revealed nitrogen in both fractions. Vasseur concluded that the 

 nitrogen in the latter was not fertilizin nitrogen. The carbohydrate 

 was largely confined to the supernatant. Since both the super- 

 natant and precipitate fractions were nondialyzable, Vasseur 

 concluded that he had achieved a separation into protein and 

 carbohydrate components. However, it appears that the evidence 

 for separate protein and carbohydrate moieties in the fertilizin 

 molecule is incomplete. 



The sulfate is probably esterified to the carbohydrate. Only 

 half of the fucose of Echinocardium cordatum fertilizin is readily 

 attacked by periodate. From this Vasseur (1952b) suggests that 

 the carbohydrate portion consists of a branching fucose sulfate 

 chain. Each fucose sulfate of the "backbone" is linked "laterally" 

 to a single fucose sulfate side group. Only the latter have a-glycol 

 groups free to react with the periodate. Tyler (1948c, 1949) 

 offered another explanation for the failure to readily obtain a sep- 

 aration into protein and polysaccharide components, namely, 

 that fertilizin may not be a conjugated protein in the usual sense, 



