Abstract
An octadecapeptide, H-Arg-Lys-Asp-Val-Tyr-Val-Gln-Leu-Tyr-Leu-Gln-Thr-Leu-Thr-Ala-Val-Lys-Arg-OH, corresponding to the C-terminal portion of thymopoietin II was synthesized using protecting groups removable by hydrogen fluoride treatment. The in vitro addition of the synthetic octadecapeptide was able to restore the low E-rosette forming capacity of cells in a rheumatoid arthritis patient to normal levels. The in vitro effects of pentapeptide (positions 32-36), nonapeptide (positions 33-41) and decapeptide (positions 32-41) fragments of thymopoietin on the low E-rosette forming capacity of cells of a rheumatoid arthritis patient were also compared with that of the synthetic octadecapeptide. The relative potency of the pentapeptide was 10.56 and that of the decapeptide was 25.43 based on the octadecapeptide (100.00) as a standard, but the nonapeptide was ineffective.
