Solid-phase synthesis of thymosin .beta.4: chemical and biological characterization of the synthetic peptide

Abstract

The chemical synthesis of thymosin .beta.4 using a solid-phase procedure was accomplished. The synthetic product was homogeneous on paper electrophoresis at pH 6.5, high-performance liquid chromatography on a reversed-phase column and isoelectric focusing using polyacrylamide gels. The synthetic material was also identical with the natural thymosin .beta.4 by tryptic peptide mapping, amino acid compositional analyses and polyacrylamide gel isoelectric focusing. Biologically, synthetic thymosin .beta.4 was as active as the natural compound in a terminal deoxynucleotidyltransferase induction assay in mice and in a guinea pig macrophage migration inhibition assay. The proposed structure of the peptide hormone was thus confirmed by a chemical synthesis.