title: Activity of synthetic thymosin alpha 1 C-terminal peptides in the azathioprine E-rosette inhibition assay.
abstract: The helical C-terminal portion of the thymic hormone thymosin alpha 1 exhibits immunological activities in several in vitro assays. The C-terminal region spanning positions 17-28 was subdivided into 11 overlapping peptide segments to collect further information on the molecular signal hypothesis for T lymphocyte differentiation by thymosin alpha 1 derived peptides. All peptides were synthesized by classical means and tested in the azathioprine E-rosette inhibition assay. The results provided additional evidence that a basic-acidic-lipophilic sequence character is a possibly essential feature of a molecular signal for T cell differentiation. Five to seven structures beginning N terminally with lysine fitted this functional key. They showed immunological in vitro activities similar to and even better than the parent hormone thymosin alpha 1 in the ability to express in immature spleen cells from adult thymectomized mice the E-receptor sensitive to azathioprine inhibition.
mesh_terms: D000818:Animals; D001379:Azathioprine / Q000494:pharmacology*; D051379:Mice; D010446:Peptide Fragments / Q000276:immunology*; D012397:Rosette Formation; D013154:Spleen / Q000166:cytology; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000276:immunology; D013934:Thymectomy; D013947:Thymosin / Q000276:immunology*; D013951:Thymus Hormones / Q000276:immunology*
chemical_list: D010446:Peptide Fragments; D013951:Thymus Hormones; D013947:Thymosin; D001379:Azathioprine