title: Antigenic and structural characteristics of an immunoglobulin-related peptide purified from marmoset T-lymphoma cells.
abstract: A 7800 Mr peptide, apparently derived from a 70,000 Mr immunoglobulin-related protein synthesized by a marmoset T-lymphoma cell line, bears immunoglobulin-related determinants apparently contained in a disulfide-bonded loop comparable to that of the VH fragment of classical H chain. A membrane-enriched, crude particulate fraction was prepared from marmoset T-lymphoma cells, and peptides generated by papain digestion of the particulate fraction were selectively purified by affinity chromatography using IgG purified from serum of a goat immunized with the Fab fragment of a human Waldenstrom macroglobulin. The smallest of the affinity-purified peptides was particularly reactive with unfractionated goat anti Fab (G alpha Fab) serum, purified IgG from G alpha Fab serum, and with antibodies affinity purified from G alpha Fab serum using Waldenstrom macroglobulins. Partial specificity of G alpha Fab antibodies was determined by competition radioimmunoassay and radioimmunoprecipitation assays. High-performance reverse-phase liquid chromatography was used for final purification of the smallest peptide which retained its reactivity with G alpha Fab serum and affinity-purified G alpha Fab antibodies. The apparent molecular weight of the peptide, determined by gel filtration in 6 M guanidine, was estimated at 3900 in its native state but increased to 7800 after reduction and alkylation, indicating a role for a disulfide bond in the tertiary structure of the peptide. The amino acid composition of the peptide was presented, and its possible relationship to immunoglobulin-like T-cell surface proteins was discussed.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000961:Antilymphocyte Serum / Q000032:analysis; D002460:Cell Line; D055598:Chemical Phenomena; D002621:Chemistry; D000939:Epitopes / Q000032:analysis* / Q000302:isolation & purification; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology / Q000302:isolation & purification; D007074:Immunoglobulin G / Q000302:isolation & purification; D007136:Immunoglobulins / Q000276:immunology* / Q000302:isolation & purification; D008223:Lymphoma / Q000276:immunology*; D008970:Molecular Weight; D010455:Peptides / Q000276:immunology* / Q000302:isolation & purification; D011946:Receptors, Antigen / Q000032:analysis; D012452:Saguinus; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000596:Amino Acids; D000961:Antilymphocyte Serum; D000939:Epitopes; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D007136:Immunoglobulins; D010455:Peptides; D011946:Receptors, Antigen