Studies in Glycogen Storage Disease Type III: Kinetics of Amylo-1,6-Glucosidase in Human Erythrocytes

Abstract

The affinity constant of amylo-1,6-glucosidase for glucose was determined in hemolyzed erythrocytes obtained from probable heterozygote carriers of glycogen storage disease type III, and from normal persons with high and low values of the enzyme. A common K_m was demonstrated in all cases, indicating that diminished enzyme activity may be caused by a reduced production of the normal enzyme (possibly coexistent with an inactive enzyme modification) or the presence of noncompetetive inhibitors. No evidence for structural modifications of the enzyme in a normal population was obtained in this study.

Key Words:

• Amylo-1,6-glucosidase
• erythrocyte
• glycogen
• glycogenosis
• heterozygote
• isoenzymes
• kinetics