title: Intramolecular heterogeneity of ligand binding by two IgM antibodies derived from murine hybridomas.
abstract: The ligand binding properties of two murine anti-DNP IgM hybridoma antibodies were analyzed. These IgM antibodies, designated NP3-17 C1-20 and SP2/0 I-64 C1-12, each displayed an average of only five high affinity binding sites for the DNP moiety. Reductive 7S subunits of both of these proteins each adsorbed to and were hapten eluted from DNP affinity columns. These subunits, when examined by equilibrium dialysis, each contained an average of one high affinity binding site. Structural analysis of these molecules indicated each to be homogeneous. Results obtained from trypsin hydrolysis of each molecule indicated that differences in conformation of the binding sites may account for the observed binding heterogeneity.
mesh_terms: D000614:Aminocaproates / Q000276:immunology; D000818:Animals; D001666:Binding Sites, Antibody; D004591:Electrophoresis, Polyacrylamide Gel; D006825:Hybridomas / Q000276:immunology*; D007140:Immunoglobulin Fab Fragments / Q000032:analysis; D007075:Immunoglobulin M / Q000276:immunology / Q000378:metabolism*; D008024:Ligands; D051379:Mice; D008807:Mice, Inbred BALB C; D014357:Trypsin
chemical_list: D000614:Aminocaproates; D007140:Immunoglobulin Fab Fragments; D007075:Immunoglobulin M; D008024:Ligands; C031746:6-N-(2,4-dinitrophenyl)aminohexanoic acid; D014357:Trypsin