Abstract
Acid α-glucosidase (AG) of 15% of mean control was found in cultured skin fibroblast (FB) of a patient with late onset AG deficiency. AG was purified from normal and from deficient FB by affinity chromatography. Placental AG was purified to homogeneity with CM-Sephadex C-50, ammonium sutfate precipitation, dialysis, Amicon filtration, affinity chromatography by Sephadex G-100 and DEAE-cellulose ion-exchange chromatography. Two activity peaks and a shoulder were eluted from DEAE-cellulose with a NaCI gradient. The two peaks and the shoulder had different specific activities and on aerylamide disc electrophoresis each gave one protein band with different mobilities corresponding to the enzyme activity. The pH optimum, Km, Vmax, etectrophoretic mobility, thermal denaturation at pH 4.0 and 7.0, and inhibition by turanose, α-methyiglucoside and trehalose were the same in purified wild type and mutant enzymes. A greater inhibition was found with all inhibitors when glycogen, rather than maltose, was the substrate. The Vmax of the placental enzyme was greater than that of the FB enzyme. Heating crude extracts from normal and deficient FB gave an initial increase in specific activity which was not present with purified enzyme. We are now producing antibodies against the enzyme to determine whether or not the amount of enzyme protein in deficient cells differs from that in normal cells.
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Baratis, N., Labadie, G. & Hirschhorn, K. ACID α-GLUCOSIDASE FROM NORMAL AND DEFICIENT CELLS. Pediatr Res 11, 452 (1977). https://doi.org/10.1203/00006450-197704000-00496
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DOI: https://doi.org/10.1203/00006450-197704000-00496