Antigen-binding molecules of T-cells charge heterogeneity and structural lability.

T-cell products released by immune cells during culture and which bind specifically the nominal antigens, trinitrophenol (TNP) or oxazalone, were isolated from culture media by hapten-affinity chromatography and compared by isoelectric focusing and 2D-gel analysis. These proteins and an azobenzenearsonate-specific T-cell product synthesized in vitro by translation of mRNA from an azobenzenearsonate-specific T-cell hybrid were also compared for structural lability of the polypeptides. Polyclonal T-cell antigen-binding molecules (TABM) specific for TNP or oxazalone showed marked charge heterogeneity and distinctions in isoelectric focusing in an acidic pH gradient, while the azobenzenearsonate-specific, clonal T-cell product displayed restricted focusing. All TABM studied showed dissociation of Mr 70,000 polypeptides to Mr 45,000 and 25,000 polypeptides after treatment with guanidine. The results provide further evidence for distinctions and similarities between TABM.