title: Monoclonal antibody to amphomycin. A tool to study the topography of dolichol monophosphate in the membrane.
abstract: Understanding the topographical orientation of dolichol monophosphate (Dol-P) in the membrane of the endoplasmic reticulum (ER) is of utmost importance for studying the regulation of asparagine-linked protein glycosylation in eukaryotic cells. This was practically impossible due to the nonavailability of a suitable probe. Recent studies on the specific interaction between a lipopeptide, amphomycin, and Dol-P, provided an insight to develop a monospecific antibody to amphomycin which could recognize the amphomycin-Dol-P complex in order to detect Dol-P immunocytochemically in the ER membrane. We report herein the successful production of a monoclonal antibody to amphomycin. The antibody belongs to the IgG+IgM subclasses and is specific for amphomycin when analyzed by the enzyme-linked immunoassay and immunoblot procedures. The antibody recognizes with equal potency both the native amphomycin and also mild acid-hydrolyzed amphomycin from which N-terminal fatty acylated aspartic acid has been removed. Preincubation of amphomycin with the antibody partially reduced the inhibitory action of amphomycin on dolichol phosphate mannosyltransferase (EC 2.4.1.83). Furthermore, exposure of capillary endothelial cells to amphomycin, followed by the monoclonal antibody to amphomycin, followed sequentially by staining with FITC-conjugated goat anti-mouse IgG and examination under a fluorescent microscope gives intense fluorescence at the perinuclear region of the cell with a structure reminiscent of the ER.
authors.affiliation: Department of Biochemistry & Nutrition, School of Medicine, University of Puerto Rico, San Juan 00936-5067.
authors.forename: D K
authors.initials: DK
authors.lastname: Banerjee
authors.forename: A M
authors.initials: AM
authors.lastname: Diaz
authors.forename: T M
authors.initials: TM
authors.lastname: Campos
authors.forename: C
authors.initials: C
authors.lastname: Grande
authors.forename: W J
authors.initials: WJ
authors.lastname: Kozek
authors.forename: K
authors.initials: K
authors.lastname: Baksi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D002240:Carbohydrate Sequence; D002417:Cattle; D004288:Dolichol Phosphates / Q000737:chemistry*; D004721:Endoplasmic Reticulum / Q000737:chemistry*; D006825:Hybridomas / Q000276:immunology; D007150:Immunohistochemistry; D007425:Intracellular Membranes / Q000737:chemistry*; D055666:Lipopeptides; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D004288:Dolichol Phosphates; D055666:Lipopeptides; D009842:Oligopeptides; C028306:dolichol monophosphate; C004423:amphomycin