title: Active site structure and antigen binding properties of idiotypically cross-reactive anti-fluorescein monoclonal antibodies.
abstract: This report includes complete VH and V kappa nucleotide and deduced amino acid sequences of idiotypically cross-reactive monoclonal anti-fluorescein antibodies that differed greater than 10(5)-fold in affinity. High affinity monoclonal antibody 4-4-20 and intermediate affinity antibodies 10-25, 5-14, 9-40, 12-40, and 3-24 utilized greater than or equal to 90% homologous VHIIIC germ-line genes. Extensive D segment length and sequence variability were observed; however, compensatory germ-line JH4 (4-4-20 and 3-24) or JH3 (10-25, 5-14, 9-40, and 12-40) sequence lengths resulted in H chain CDR3 + FR4 to be a constant 18 amino acids. In addition, each antibody and low affinity 3-13 rearranged greater than or equal to 96% homologous V kappa II genes to J kappa 1, except for 10-25 (J kappa 5) and 3-13 (J kappa 4). Resolved crystal structure of complexed fluorescein and 4-4-20 Fab fragments revealed residues HisL27d, TyrL32, ArgL34, SerL91, TrpL96, and TrpH33 acted as hapten contact residues. Antibodies 5-14, 9-40, 12-40, and 3-24 primary structures possessed identical contact residues as 4-4-20 except for the substitution of HisL34 for ArgL34. Thus, ArgL34 was implicated in the increased affinity of monoclonal antibody 4-4-20. Finally, it was difficult to correlate extensive H chain CDR3 residue heterogeneity directly with fluorescein binding and idiotypy.
authors.affiliation: Department of Microbiology, University of Illinois, Urbana 61801.
authors.forename: W D
authors.initials: WD
authors.lastname: Bedzyk
authors.forename: J N
authors.initials: JN
authors.lastname: Herron
authors.forename: A B
authors.initials: AB
authors.lastname: Edmundson
authors.forename: E W
authors.initials: EW
authors.lastname: Voss
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology*; D000915:Antibody Affinity; D000941:Antigens / Q000276:immunology*; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D019793:Fluorescein; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006825:Hybridomas / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000276:immunology; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology; D007145:Immunoglobulin kappa-Chains / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007143:Immunoglobulin Heavy Chains; D007130:Immunoglobulin Idiotypes; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; D004247:DNA; D019793:Fluorescein