title: Molecular properties of T-lymphoma immunoglobulin. II. Peptide composition of the heavy chain.
abstract: In order to obtain structural information and to facilitate studies of the covalent structure of T-cell immunoglobulin, we have performed investigations of the peptide fragments of the heavy chain of this molecule, on a comparative basis, with heavy chains of serum immunoglobulins. T-cell immunoglobulin was isolated from 125I-labelled culture medium of monoclonal continuously cultured T-lymphoma cells by means of immunoadsorbents. Peptides were prepared from the purified 125I-labelled heavy chain by means of cleavage with cyanogen bromide or digestion with trypsin. We then resolved these peptides and compared them with those peptides derived from 131I-labelled murine mu, gamma and alpha chains separately and in mixed label experiments by means of polyacrylamide gel electrophoresis in sodium dodecyl sulfate containing buffers, 2 dimensional peptide mapping and ion exchange chromatography. The profiles of the radiolabelled peptides obtained from the T-lymphoma heavy chains were quite distinct from those of murine gamma chains but indicated a structural similarity to both mu and alpha chains, which share some common peptides. These results are consistent with the antigenic and physicochemical data available and suggest that T-cell immunoglobulin is a new isotype that shows similarities to IgA and IgM, but of which the precise nature of the constant region has yet to be delineated.
mesh_terms: D000818:Animals; D002460:Cell Line; D002852:Chromatography, Ion Exchange; D004586:Electrophoresis; D007143:Immunoglobulin Heavy Chains / Q000032:analysis*; D008223:Lymphoma; D051379:Mice; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis*; D011487:Protein Conformation; D013601:T-Lymphocytes / Q000276:immunology*; D014357:Trypsin / Q000494:pharmacology
chemical_list: D007143:Immunoglobulin Heavy Chains; D010446:Peptide Fragments; D014357:Trypsin