title: Intramolecular localization of epitopes within an oligomeric protein by immunoelectron microscopy and image processing.
abstract: Three epitopes have been localized by immunoelectron microscopy on subunit Aa6 of the 4 x 6-meric hemocyanin of the scorpion Androctonus australis. Soluble immunocomplexes composed of monoclonal antibodies and of native hemocyanin were purified, negatively stained with uranyle acetate by the single-layer technique, and examined under the electron microscope (EM). The molecule images were digitized, aligned, and submitted to correspondence analysis according to the method of Van Heel and Frank (Ultramicroscopy 6:187-194, 1981). A high-precision localization of the attachment point of the Fab arm to the antigen was achieved through a careful analysis of the average images. This method easily allowed the discrimination of epitopes located in different domains (Mr 20 kDa) of the same subunit. Nonoverlapping epitopes located in the same structural domain of subunit Aa6 could be distinguished by the stain exclusion patterns of their Fab arms. The method is general and may be used for epitope mapping in any antigen producing definite EM views.
authors: Laboratoire de Biochimie, Faculté de Pharmacie, Université François Rabelais, Tours, France.
authors: N
authors: N
authors: Boisset
authors: J
authors: J
authors: Frank
authors: J C
authors: JC
authors: Taveau
authors: P
authors: P
authors: Billiald
authors: G
authors: G
authors: Motta
authors: J
authors: J
authors: Lamy
authors: P Y
authors: PY
authors: Sizaret
authors: J
authors: J
authors: Lamy
mesh_terms: D000911:Antibodies, Monoclonal; D000939:Epitopes / Q000032:analysis*; D006433:Hemocyanins / Q000302:isolation & purification; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D008958:Models, Molecular; D011506:Proteins / Q000276:immunology*; D009626:Terminology as Topic
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D011506:Proteins; D006433:Hemocyanins