title: Further observations on the activation of lysosomal acid alpha-glucosidase by cortisone derivatives.
abstract: 1. Cortisone acetate activates the acid alpha-glucosidase in rat liver slices and in isolated liver lysosomes. 2. The reaction is steroid specific and moreover does not occur with lysosomal acid phosphatase or beta-galactosidase. 3. After pretreatment of the lysosomes with cortisone, substrate (maltose) binding to the soluble lysosomal acid alpha-glucosidase is not affected, but the steroid does increase the V(max.) value. Membrane-bound enzyme is not activated by cortisone. 4. 4-[(14)C]Cortisone is preferentially bound to the lysosomal membrane and the possible involvement of this structure in the activation phenomenon is discussed.
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D002247:Carbon Isotopes; D003348:Cortisone / Q000378:metabolism / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005696:Galactosidases / Q000378:metabolism; D005959:Glucosidases / Q000378:metabolism*; D066298:In Vitro Techniques; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D008247:Lysosomes / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D008566:Membranes / Q000201:enzymology; D051381:Rats; D012995:Solubility; D013329:Structure-Activity Relationship
chemical_list: D002247:Carbon Isotopes; D000135:Acid Phosphatase; D005696:Galactosidases; D005959:Glucosidases; D003348:Cortisone