Synthesis of a thymosin beta 4-like peptide, deacetyl-thymosin beta Xen4, and its restorative effect on depressed lymphocyte blastogenic response to phytohemagglutinin (PHA) in uremic patients.

An analog of thymosin beta Xen4 isolated from oocytes of Xenopus laevis, deacetyl-thymosin beta Xen4, was synthesized by assembling 6 peptide fragments, followed by deprotection with 1 M trifluoromethanesulfonic acid-thioanisole (molar ratio, 1:1) in trifluoroacetic acid in the presence of dimethylselenium. Finally, the deprotected peptide was incubated with dithiothreitol to reduce sulfoxide on the methionine side chain. The synthetic tritetracontapeptide was found to have a restoring effect on the impaired blastogenic response of T-lymphocytes isolated from uremic patients.