Action of Rice α-Glucosidase on Maltose and Starch |
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Authors: | Nobuyuki Takahashi Tokuji Shimomura |
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Institution: | Department of Agricultural Chemistry, Faculty of Agriculture, Hokkaido University |
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Abstract: | Rice seeds possess α-glucosidase I and II, and the action of the α-glucosidases on maltose and starch was studied. The activity on starch was increased 2.3~2.6 times in both enzymes at the concentration of 50 mM of potassium chloride. Such activation was also caused by mono and di-valent cations. The activity on maltose was not influenced by the cations. In mixed substrate experiments, liberation of 14C-glucose from 14C-maltose was not inhibited in the presence of starch, and this was also the case with that from 14C-starch in the existence of maltose. From these results, it was suggested that the α-glucosidases possess maltose-hydrolyzing site and starch-hydrolyzing site separately, and also probably regulatory. The α-glucosidases liberated only glucose from starch, and were presumed to complete hydrolysis of starch after longer incubation. |
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Keywords: | auxin biosynthesis inhibitor indole-3-acetic acid indole-3-oxoethylphosphonic acid |
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