Bovine generalised glycogenosis type II. Uptake of lysosomal alpha-glucosidase by cultured skeletal muscle and reversal of glycogen accumulation.
acid alpha-glucosidase (EC 3.2.1.20) was purified from fetal bovine muscle by affinity chromatography on concanavalin A and Sephadex G-100 and added to the culture medium of mature muscle cultures from animals affected by glycogenosis type II. The enzyme activity in homogenates of treated cultures was significantly increased within 4 h of the addition of enzyme, was maximal by 18 h and the internalised activity was stable for at least 48 h after the removal of the enzyme from the culture medium. The acid alpha-glucosidase activity was internalised with an uptake constant of 300 nM and a Vmax of uptake of 133 nmol/h per mg protein. The glycogen concentration in affected cultures treated with exogenous acid alpha-glucosidase for 24 h had decreased by 20% and after a further 24 h of culture was comparable to the concentration observed in cultures from non-affected animals.
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000201:enzymology / Q000378:metabolism*; D002478:Cells, Cultured; D005959:Glucosidases / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism*; D006008:Glycogen Storage Disease / Q000662:veterinary*; D006009:Glycogen Storage Disease Type II / Q000201:enzymology / Q000378:metabolism / Q000662:veterinary*; D008247:Lysosomes / Q000201:enzymology*; D009132:Muscles / Q000201:enzymology / Q000378:metabolism*; D000520:alpha-Glucosidases / Q000378:metabolism*
D006003:Glycogen; D005959:Glucosidases; D000520:alpha-Glucosidases