EFFECTS OF CHEMICAL MODIFICATION ON ANTIGENICITY OF HUMAN AND RABBIT IMMUNOGLOBULIN-G

  • 1 January 1976
    • journal article
    • research article
    • Vol. 30  (6) , 881-894
Abstract
To characterize the precise structure within human and rabbit IgG [immunoglobulin G] molecules against which general rheumatoid factors are directed, an immunochemical comparison was made of the effects of the selective substitution of specific amino acid side-chains on various types of antigenicity exhibited by human and rabbit IgG. The .epsilon.-amino groups of lysine residues were substituted by citraconylation and carbamylation; tyrosine residues were substituted by nitration with tetranitromethane. The autoantigenic determinants of human IgG are apparently structurally distinct from species-specific ones and from certain Fc-located allotypic markers (Gm(a) and Gm(x)). Lysine residues are probably not involved in the site of IgG reactivity with general rheumatoid factors, in contrast to tyrosine residues which appear to be implicated in the activity of human, but not rabbit IgG.