title: Distribution of saccharide residues on membrane fragments from a myeloma-cell homogenate: its implications for membrane biogenesis.
abstract: Ferritin conjugates of two plant agglutinins, concanavalin A and ricin, have been used as specific electron microscopic stains for covalently-bound saccharide residues on membrane fragments from a myeloma-cell homogenate. The results indicate that different saccharide residues are uniformly localized to a single surface of each membrane fragment. In particular, the ferritin-concanavalin A conjugate binds exclusively to the cisternal side of membrane fragments of the rough endoplasmic reticulum. If it is postulated that the biogenesis of eukaryotic plasma membranes involves an assembly-line process from precursor intracellular membranes, these observed asymmetric distributions of saccharides on cell membranes can be explained.
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D003208:Concanavalin A; D005293:Ferritins; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D009101:Multiple Myeloma / Q000473:pathology; D009194:Myeloma Proteins / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism*; D010954:Plasmacytoma / Q000378:metabolism; D011485:Protein Binding; D012276:Ricin; D013194:Staining and Labeling
chemical_list: D009194:Myeloma Proteins; D009844:Oligosaccharides; D003208:Concanavalin A; D005293:Ferritins; D012276:Ricin