title: Spin labeling of immunoglobulin M and E carbohydrates.
abstract: The analysis of ESR spectra of spin-labeled human myeloma immunoglobulins M and E has shown the rotation of spin labels bound to carbohydrates to be restricted most probably due to close attachment of oligosaccharide chains to protein parts of molecules. The values of rotational correlation times for IgM, IgMs and Fc5, spin-labeled at carbohydrates, were found to be equal to 7,7 and 6 ns, respectively. These data pointed to the existence of internal lability of the Fc5 fragment. ESR spectra of IgE spin-labeled at carbohydrates also reflected restricted rotation of the spin label, but the presence of a more than one wide extremum spoke in favour of differences in the degree of immobilization between different oligosaccharide chains. The value of rotational correlation times calculated for IgE, spin-labeled at protein and carbohydrate moieties, were similar (60 and 66 ns). These data confirmed the previously found rigidity of IgE molecule as compared with IgG molecule.
mesh_terms: D002241:Carbohydrates; D055598:Chemical Phenomena; D002621:Chemistry; D004578:Electron Spin Resonance Spectroscopy; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007122:Immunoelectrophoresis; D007073:Immunoglobulin E / Q000032:analysis*; D007141:Immunoglobulin Fc Fragments / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis*; D009101:Multiple Myeloma / Q000276:immunology; D009374:Neoplasms, Experimental
chemical_list: D002241:Carbohydrates; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007073:Immunoglobulin E