Variable region primary structures of a high affinity anti-fluorescein immunoglobulin M cryoglobulin exhibiting oxazolone cross-reactivity.
Previous studies of murine IgM hybridoma protein 18-2-3, derived from an (NZB/NZW)F1 mouse following hyperimmunization with fluorescein (Fl)-conjugated keyhole limpet hemocyanin, demonstrated a high affinity for Fl (Ka = 2.9 x 10(10) M-1) and cryoprecipitation that was abrogated upon Fl binding to the antibody-combining site. V region sequences of 18-2-3 were determined by Edman degradation and nucleotide sequence analysis. The VH region of 18-2-3 was encoded by a gene VHI(B) of the Q52 VH family with 96% homology to anti-oxazolone antibody NQ7.5.3 but utilized a larger D region (DQ52 plus N region). The V kappa region of 18-2-3 was encoded by a gene V kappa IV with an amino acid sequence 97% homologous to that of anti-oxazolone antibody NQ11.1.18. Although monoclonal anti-Fl antibodies 18-2-3 and 4-4-20 possessed similar binding affinities and quenched bound fluorescein to the same extent (Qmax greater than 96%), they utilized different VH, D, V kappa, and J kappa genes, but the same JH gene segment (JH4). Solid-phase analyses showed that 18-2-3 was not idiotypically related to 4-4-20 and 9-40, prototypic anti-Fl antibodies. Fine specificity binding patterns of Fl analogues by 18-2-3 IgM and IgMs were distinct from other anti-Fl antibodies. Monoclonal antibody 18-2-3 bound phenyloxazolone bovine serum albumin with a lower affinity than for Fl-bovine serum albumin. The first hypervariable region of the 18-2-3 light chain showed homology to human cryoglobulins. This is the first variable region sequence of a murine IgM which self-aggregates at low temperature.
Dombrink-Kurtzman
M A
MA
Department of Microbiology, University of Illinois, Urbana 61801.
Johnson
L S
LS
Riordan
G S
GS
Bedzyk
W D
WD
Voss
E W
EW
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000915:Antibody Affinity; D000918:Antibody Specificity; D000941:Antigens / Q000276:immunology; D001483:Base Sequence; D003450:Cryoglobulins / Q000235:genetics / Q000276:immunology*; D019793:Fluorescein; D005452:Fluoresceins / Q000276:immunology*; D006433:Hemocyanins / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000276:immunology; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D007147:Immunoglobulin Light Chains / Q000235:genetics / Q000276:immunology; D007075:Immunoglobulin M / Q000235:genetics / Q000276:immunology*; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008814:Mice, Inbred NZB; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010080:Oxazoles / Q000276:immunology*; D010081:Oxazolone / Q000276:immunology*; D012689:Sequence Homology, Nucleic Acid; D012710:Serum Albumin, Bovine / Q000276:immunology
D000911:Antibodies, Monoclonal; D000941:Antigens; D003450:Cryoglobulins; D005452:Fluoresceins; D007143:Immunoglobulin Heavy Chains; D007130:Immunoglobulin Idiotypes; D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D010080:Oxazoles; D010081:Oxazolone; D012710:Serum Albumin, Bovine; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin; D019793:Fluorescein