title: Localization of beta-glucan synthases on the membranes of cultured Lolium multiflorum (ryegrass) endosperm cells.
abstract: The distribution of beta-glucan synthases between plasma membranes and intracellular membranes of suspension-cultured Italian-ryegrass (Lolium multiflorum Lam.) endosperm cells was examined. Highly purified plasma membranes prepared from protoplasts were only slightly enriched in beta-glucan synthases assayed at 10 microM- and 1 mM-UDP-glucose. Most beta-glucan synthase was associated with intracellular membranes. These membranes were fractionated on a linear sucrose density gradient and were resolved into different membrane fractions containing beta-glucan synthases. Beta-Glucan synthases assayed at 10 microM-UDP-glucose were found in a fraction banding at a density of 1.11 g . cm-3, but most of the beta-glucan synthase assayed at 1 mM-DDP-glucose was at a density of 1.04 g . cm-3.
mesh_terms: D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D005964:Glucosyltransferases / Q000378:metabolism*; D007425:Intracellular Membranes / Q000201:enzymology; D050356:Lipid Metabolism; D006109:Poaceae / Q000201:enzymology; D011523:Protoplasts / Q000201:enzymology; D012639:Seeds / Q000201:enzymology*; D014532:Uridine Diphosphate Glucose / Q000378:metabolism
chemical_list: D005964:Glucosyltransferases; D014532:Uridine Diphosphate Glucose