[Synthesis and function analysis of a new thrombopoietin (TPO) mimic peptide]

In order to find a new TPO-mimic peptide with similar activity to TPO while reducing the side effects, a TPO-mimic peptide (P1) screened from a random peptide library was restructured. The new structure of the TPO mimic peptide (P2) was synthesized. After coupling P2 with Dextran 10 and performing intermolecular oxidation, dextran-coupled and dimerized form of P2 were obtained, naming D-P2 and (P2)(2) respectively. The activities of the peptides in vitro were measured with MTT method. The results showed that the EC50 of P2 was 20 nmol/L, 700 times higher than P1. The EC50 of D-P2 and (P2)(2) were 0.35 nmol/L and 0.14 nmol/L, respectively. After administrating to the mouse, the peptides increased the number of platelets in the blood circulation obviously without influence on other blood cells. In conclusion, the TPO-mimic peptides have prospects in treating diseases related with thrombocytopenia.