hide
Free keywords:
Antibodies, Bacterial/im [Immunology]; Cysteine Endopeptidases/im [Immunology]; *Cysteine Endopeptidases/ul [Ultrastructure]; Macromolecular Systems; Microscopy, Electron; Molecular Structure; Molecular Weight; Multienzyme Complexes/im [Immunology]; *Multienzyme Complexes/ul [Ultrastructure]; Support, Non-U.S. Gov't; *Thermoplasma/en [Enzymology]
Abstract:
The subunit topography of the Thermoplasma acidophilum proteasome was determined by immunoelectron microscopy using monospecific antibodies directed against the two constituent subunits (alpha,beta). Anti-alpha-subunit IgG was found to bind to the outer disks of the cylinder- or barrel-shaped molecule, while the binding sites of the anti-beta-subunit IgG were mapped on the two inner rings. Probably the homologues of the two subunits in the compositionally more complex but isomorphous eukaryotic proteasomes occupy equivalent positions.
