PARTIAL STRUCTURE OF A RAT IGD MOLECULE WITH A DELETION IN THE HEAVY-CHAIN

  • 1 January 1980
    • journal article
    • research article
    • Vol. C131  (3) , 363-388
Abstract
The isolation, purification and characterization of the rat IR-731 monoclonal Ig [derived from plasmacytoma cells] is reported. The molecule is IgD-like, as appreciated from immunochemical and biochemical characteristics. H and L chains, Fab and Fc tryptic fragments were isolated and analyzed; partial sequence data were obtained, including most cysteyl-containing peptides. The H chain contains a deletion which encompasses most of the CH2 [H chain constant region 2] domain and the beginning of the CH3 domain, an observation which does not reflect the intron-exon organization depicted for some murine H chains at the gene level. Basic structural features of the hinge region of the IgD molecule (extreme susceptibility to proteolytic enzymes, presence of basic amino acids near its COOH-terminus) were found for the IR-731 molecule. Partial sequence of the L chains indicates the existence of .KAPPA. subgroups in the rat. Very limited amino acid changes were identified in the .KAPPA. constant region, suggesting a possible, but limited, polymorphism which might be isotypic and/or allotypic in nature.