title: Direct visualization of colloidal gold-bound molecules and a cell-surface receptor by ultrahigh-resolution scanning electron microscopy.
abstract: The structure of protein A-coated colloidal gold particles, and of macrophage cell-surface receptors conjugated with immunogold particles, was studied using an ultrahigh-resolution scanning electron microscope. Protein A, when conjugated with 15-nm gold, formed a coat completely surrounding the particle. Particles conjugated with both protein A and immunoglobulin G (IgG) were similar, but with additional protrusions formed by the IgG. IgG molecules directly bound to gold were resolved sometimes as complexes of three units, sometimes as more filamentous, V-shaped structures. On the cell surface of macrophage reacted with a monoclonal antibody to Mac-1 antigen (the murine C3bi receptor) followed by protein A-gold, gold particles were seen to be linked via the IgG to the receptor, visualized as a round granule.
authors.affiliation: Department of Anatomy, Tottori University School of Medicine, Yonago, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: Mitsushima
authors.forename: N
authors.initials: N
authors.lastname: Yamagata
authors.forename: Y
authors.initials: Y
authors.lastname: Kashima
authors.forename: H
authors.initials: H
authors.lastname: Takayama
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology / Q000648:ultrastructure; D006046:Gold; D007074:Immunoglobulin G; D016177:Macrophage-1 Antigen / Q000648:ultrastructure; D008264:Macrophages / Q000276:immunology / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D013205:Staphylococcal Protein A
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D016177:Macrophage-1 Antigen; D013205:Staphylococcal Protein A; D006046:Gold