Amylose isomerase

Rabbit-muscle extracts contain the enzyme amylose isomerase, which also catalyzes the degradation of (1—>6)-interchain linkages. i -i i This reaction is not hydrolytic, but appears to be a reversible transglucosylation. Amylose isomerase preparations are heterogeneous, and, on electrophoresis, four components of various activity and ribonucleic acid content are obtained. The in vivo significance of this enzyme is not yet established. 

Petrova - reported a nonphosphorolytic enzyme fraction from rabbit muscle, named amylose isomerase. This enzyme preparation is similar... 

Eurther conversion (saccharification) to dextrose can be done using glucoamylase. Starch consists of polymeric linear a-1,4 linked dextrose units (amylose, 25 % of the starch) and polymeric mixed a-l,4/a-l,6 linked dextrose units (amylopectin, 75 % of the starch). Eor enzymatic degradation besides a-1,4 specific amylases also a-1,6 specific amylases (pullulanases) are required. A portion of the dextrose can be converted into fructose with a glucose isomerase yielding a high fructose com symp (MFCS). 

The main industrial use of starch is as a basic raw material for the production of syrups, glucose and fructose being the most widely produced sweeteners. In the United States, approximately 764 million bushels of sweeteners were produced in the year 2006. About 70% of these sweeteners were high-fructose maize syrups (U.S. Department of Agriculture, Economic Research Service 2009). The biotransformation of starch into syrups consists of the hydrolysis of amylose and amylopectin chains by specific amylolytic enzymes (BeMiller and Whistler 2009, Whistler et al. 1984). The glucose isomerase enzyme is used to convert glucose into the sweeter fructose, present in fructose syrups, which are in high production and demand. 

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