Recombinant Human PD-ECGF/Thymidine Phosphorylase Protein

PD-ECGF, also known as TPase and gliostatin, is produced by placenta, platelets, liver, lung, spleen, lymph nodes, and peripheral lymphocytes. It is overexpressed by many tumors in response to chemical or physical stress. PD-ECGF promotes endothelial cell proliferation and chemotaxis and promotes angiogenesis. PD-ECGF is a key enzyme in the pyrimidine nucleoside salvage pathway. It also metabolizes and inactivates chemotherapeutic drugs such as 5-fluorouracil and its derivatives. The human PD-ECGF cDNA encodes a 482 amino acid (aa) polypeptide with a 10 aa propeptide. The protein is localized mostly within the producer cells. N-terminal truncation, resulting in proteins lacking 10 aa and 6 aa, has been observed in PD-ECGF purified from platelets and placenta, respectively. In solution, PD-ECGF exists as a non-disulfide linked homodimer. The latter protein was purified from quiescent astrocytes and described as an astrocyte and astrocytoma cell growth inhibitor based on its ability to inhibit ³H-thymidine incorporation.