Gyotoku J, Imaizumi A, Terada S, Kimoto E
Int J Pept Protein Res. 1983 Feb;21(2):135-44. doi: 10.1111/j.1399-3011.1983.tb03087.x.
A series of analogs of serum thymic factor (Facteur Thymique Sérique; FTS) devoid of C- and N-terminal few residues were synthesized and their ability to induce Thy-l (theta) antigen in vitro on mouse T lymphocyte precursors was examined. The pentapeptide moiety (Lys-Ser-Gln-Gly-Gly) seems to be important for the expression of agonistic activity. Some of the short chain peptides showed antagonistic properties. Synergistic activation by two inactive analogs was observed.
