title: A synthetic pentapeptide with biological activity characteristic of the thymic hormone thymopoietin.
abstract: The pentapeptide arginyl-lysyl-aspartyl-valyl-tyrosine, corresponding to amino acid residues 32--36 in thymopoietin, was synthesized. In vitro, this pentapeptide induced the differentiation of murine prothymocytes to thymocytes and inhibited differentiative induction of cells of the B lineage. This combination of actions is presently unique to the parent molecule thymopoietin. In vivo, the pentapeptide reduced the high numbers of autologous rosette-forming cells normally present in the spleens of athymic mice; this also is a property of thymopoietin. These results suggest that this readily synthesized pentapeptide corresponds to an active site of thymopoietin and might serve as a therapeutic substitute for thymopoietin.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D003165:Complement System Proteins; D007519:Isoantigens / Q000032:analysis; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology*; D051379:Mice; D008819:Mice, Nude / Q000276:immunology; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology*; D011955:Receptors, Drug / Q000032:analysis; D013329:Structure-Activity Relationship; D013946:Thymopoietins / Q000494:pharmacology*; D013951:Thymus Hormones / Q000494:pharmacology*
chemical_list: D000954:Antigens, Surface; D007519:Isoantigens; D009842:Oligopeptides; D011955:Receptors, Drug; D013946:Thymopoietins; D013951:Thymus Hormones; D003165:Complement System Proteins