Acid Amyloglucosidase and Carbohydrate Regulation.

Abstract

A procedure for purification of an acid amyloglucosidase of fungal origin is described. The effect of the purified enzyme on tissue glycogen content and blood glucose and plasma insulin level was investigated in normal and alloxan diabetic mice.
1) Acid amyloglucosidase was purified from a commercial amyloglucosidase preparation by column chromatography on DEAE-cellulose followed by gel filtration on Sephadex G-150. The enzyme was electrophoretically pure and glucose was found to be the only low molecular reaction product with glycogen as substrate.
2) Intravenous injection of the enzyme to normal mice induced a long acting depression of the blood glucose level and a moderate elevation of the plasma insulin level. Liver and muscle glycogen content was found to be markedly decreased.
3) Enzyme administration to alloxan diabetic mice (diabetes duration: about 2 months) markedly depressed blood glucose and liver glycogen levels and caused a highly significant increase in the plasma insulin level. Elevated levels of plasma insulin and reduced blood glucose levels were also found in subdiabetic animals after enzyme treatment. The hypothesis is put forward that hydrolytic breakdown of β-cell glycogen by acid amyloglucosidase may play a role in insulin secreting mechanisms.

Key words

Acid Amyloglucosidase - Purification - Tissue Glycogen - Blood Glucose - Plasma Insulin - Alloxan Diabetes

1 This work was supported by the Medical Faculty, University of Lund, Sweden. The skilful technical assistance of Mrs. Lena Kvist is gratefully acknowledged.

1 This work was supported by the Medical Faculty, University of Lund, Sweden. The skilful technical assistance of Mrs. Lena Kvist is gratefully acknowledged.