ANTI-ENZYME IMMUNITY 



227 



The processes involved in the synthesis of starch and glycogen from 

 glucose is represented by the following scheme: 

 Adenosinetriphosphate + glucose 



Hexokinase 



Glucose-6-phosphate 



Phosphoglucomutase 



Glucose- 1 -phosphate 

 Phosphorylase 



Polysaccharide -f- inorganic phosphate 

 (starch, glycogen) 



The conversion of glucose- 1 -phosphate to polysaccharide does not 

 take place in the presence of highly purified phosphorylase (muscle or 

 potato). The presence of an amount of starch, or glycogen, or dextrin 

 as a priming or activating agent is necessary. Only the branched frac- 

 tion of natural starch (amylopectin) possesses activating power. This 

 catalytic polysaccharide is pictured as a central nucleus with side chains 

 which are lengthened by the addition of glucose units through 

 repetition. Linear polysaccharides have been found to lack the activat- 

 ing ability in the synthesis of this polysaccharide (Cori, 1945; Cori 

 etal 1945;Hassid, 1945). 



Synthesis of sucrose from glucose- 1 -phosphate and fructose by a 

 phosphorylase prepared from P. saccharofhilia has been reported 

 (Hassid et al. 1944; Doudoroff, 1943) (For the synthesis of non- 

 reducing a-D-glucosido-i3-L-ketoarabinoside, and reducing 3-(a-D- 

 glucosido)-L-arabinose, Doudoroff, Hassid and Barker, 1947a; Doudor- 

 off, Barker and Hassid, 1947b). 



Phosphorylase 



GIucose-1-phosphate -[-fructose— ^ glucose- 1 -fructose-{-phosphate 



(sucrose) 



