Thymopoietin

Literature References: A polypeptide thymic hormone which selectively induces T-cell maturation from prothymocytes and inhibits B-cell differentiation. mol wt ~5500 daltons. First detected as a factor causing impaired neuromuscular transmission in myasthenia gravis, a neuromuscular disease associated with thymic abnormalities: G. Goldstein, S. Wittingham, Lancet 2, 315 (1966); G. Goldstein, ibid. 2, 119 (1968). Isoln from bovine thymus as two closely homologous forms, thymopoietins I and II: idem, Nature 247, 11 (1974); idem, Ann. N.Y. Acad. Sci. 249, 177 (1975); idem, US 4077949 (1978 to Sloan-Kettering). Bovine TPs contain 49 amino acids; I differs from II only in residues 1, 2, and 43. The active site corresponds to residues 32-36. Human TP contains 48 amino acids. Human and bovine forms are highly homologous and are identical at the active site. Proposed sequence of bTP-II: D. H. Schlesinger, G. Goldstein, Cell 5, 361 (1975). Revised sequence of II, sequence of I, isoln and sequence of splenin, q.v., a thymopoietin-like peptide found in spleen: T. Audhya et al., Biochemistry 20, 6195 (1981). Isoln and sequence of human thymopoietin: T. Audhya et al., Proc. Natl. Acad. Sci. USA 84, 3545 (1987). First synthesis of a bioactive fragment: D. H. Schlesinger, Cell 5, 367 (1975). Identification of active site and synthesis of thymopentin, q.v., the pentapeptide corresponding to the active site: G. Goldstein et al., Science 204, 1309 (1979). Total synthesis of originally proposed amino acid sequence of II: M. Fujino et al., Chem. Pharm. Bull. 25, 1486 (1977); of revised sequence: T. Abiko, H. Sekino, ibid. 35, 2016 (1987). Effect on T-cell differentiation: R. S. Basch, G. Goldstein, Proc. Natl. Acad. Sci. USA 71, 1474 (1974); M. P. Scheid et al., Ann. N.Y. Acad. Sci. 249, 531 (1975). Comparison of bioactivities of thymopoietin and splenin: T. Audhya et al., Proc. Natl. Acad. Sci. USA 81, 2847 (1984). Review of thymopoietin and other thymic hormones: J. F. Bach, J. Immunopharmacol. 1, 277-310 (1979); of thymopoietin and immunoregulation: G. Goldstein, C. Lau in Polypeptide Hormones, R. F. Beers, E. G. Bassett, Eds. (Raven Press, New York, 1980) pp 459-467; E. A. Boyse, Surv. Immunol. Res. 4, 6-10 (1985).