Cereal Chem 44:27 - 38. | VIEW
The Fate of ADPG-Alpha-Glucan Glucosyltransferase During Amylolytic Corrosion of Starch Granules, and Its Relation to Starch Granule Structure.
K. R. Chandorkar and N. P. Badenhuizen. Copyright 1967 by the American Association of Cereal Chemists, Inc.
ADPG-alpha-glucan glucose transferase is so strongly adsorbed to the starch granule that it is very difficult to extract. Because of the possibility that the enzyme might be released during amylolytic attack (corrosion) of starch granules, its activity was measured in the starch of germinating corn, barley, smooth peas, and wrinkled peas. In all cases the activity decreased. There was no increase of activity in corn juice during germination. High-amylose wrinkled-pea starch contained much more initial glucosyltransferase activity than smooth-pea starch with less amylose, but there was no direct proportionality. During a period of darkness, not only did green plants lose their starch, but the glucosyltransferase activity in the juice disappeared as well. New glucosyltransferase appeared after the plants had been re-exposed to light. The general conclusion is that glucosyltransferase protein is an integral part of starch granule structure. Corrosion in starch granules of wrinkled pea and potato was studied with the electron microscope. A correlation was shown between type of corrosion, granule structure, and changes in glucosyltransferase activity.