Monoclonal IgM Antibody Exhibiting High-Affinity Binding and Cryoglobulin Properties

• Published in: Proceedings of the National Academy of Sciences - PNAS 1983-08, Vol.80 (16), p.5071-5074
• Main Authors: Ballard, Dean W., Kranz, David M., Voss, Edward W.
• Format: Article
• Language: English
• Subjects: Active sites; Animals; Antibodies; Antibodies, Monoclonal - isolation & purification; Cell Line; Chromatography, Affinity; Cryoglobulins; Fluorescence; Fluorescent Antibody Technique; Gels; Globulins; Hybridomas - immunology; Immunoglobulin M - isolation & purification; Immunology; Kinetics; Ligands; Lymphocytes - immunology; Mice; Mice, Inbred BALB C; Monoclonal antibodies; Plasmacytoma - immunology; Protein Binding; Solubility
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.80.16.5071

A monoclonal IgM antibody (18-2-3) derived from cell fusion of (NZB × NZW) F1splenocytes following secondary immunization with fluorescein-conjugated keyhole limpet hemocyanin was shown to exhibit high intrinsic binding affinity and cryoinsolubility. Affinity-purified preparations were determined to be IgM by immunochemical, electrophoretic, and chromatographic analyses. An intrinsic association constant (Ka) of 2.9× 1010M-1(at 2 degrees C) was measured by first-order dissociation-rate analysis. Antibody solubility at low concentration (≈ 50 μ g/ml) was shown, by adsorption spectroscopy, to be temperature dependent between 4 degrees C and 32 degrees C. Insolubility at low temperature (4 degrees C) was reversible in the presence of homologous fluorescyl hapten, indicative of active site involvement in the mechanism of cryoglobulin-18-2-3 complex formation. Characteristics of clone 18-2-3 are discussed in terms of (i) its potential use as a model for examining the mechanism of cryoprecipitation and (ii) the proposed relationship between affinity maturation and the IgM to IgG class switch.