title: Localisation of acetyl-CoA: alpha-glucosaminide N-acetyltransferase in microsomes and lysosomes of rat liver.
abstract: Subcellular fractions of rat liver were obtained by differential centrifugation. The fractions enriched in lysosomes or microsomes were further fractionated in discontinuous sucrose density gradients or continuous iso-osmotic gradients made of modified colloidal silica. The fractions were analyzed for marker enzymes of the different subcellular organelles and for acetyl-CoA: alpha-glucosaminide N-acetyltransferase. The acetyl-CoA: alpha-glucosaminide N-acetyltransferase activity showed a bimodal distribution. About one fourth of the activity was associated with lysosomes, whereas the greater part of the activity was recovered in the microsomal fraction. Plasma membrane-enriched fractions contained only trace amounts of acetyl-CoA: alpha-glucosaminide N-acetyltransferase. The lysosomal and microsomal acetyl-CoA: alpha-glucosaminide N-acetyltransferases are membrane-bound and can be solubilized with Triton X-100. The pH dependence and sensitivity to various ions was similar for the lysosomal and microsomal enzyme.
mesh_terms: D000123:Acetyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002458:Cell Fractionation; D005260:Female; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008247:Lysosomes / Q000201:enzymology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008862:Microsomes, Liver / Q000201:enzymology* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000648:ultrastructure
chemical_list: D000123:Acetyltransferases; C020580:glucosamine acetyltransferase