THYMIDINE PHOSPHORYLASE FROM ESCHERICHIA COLI RECOMBINANT EXPRESSED IN E. COLI (C005B-307124)

General description

Research area: CELL SIGNALING

The E. coli thymidine phosphorylase shares 40% sequence homology with the human sequence, which is identical to the angiogenic agent platelet-derived endothelial growth factor. The purified E. coli enzyme has been shown to stimulate blood vessel growth in chick chorioallantoic membrane assays.

Application

Thymidine phosphorylase has been used:

• in a study to evaluate biomarkers for advanced breast cancer patients treated with capecitabine-based first-line chemotherapy.
• in a study to investigate implications for the clinical efficacy of nucleoside analogues.

Biochem/physiol Actions

An enzyme that catalyzes the reversible conversion of thymidine to thymine. Thymidine phosphorylase is part of the pyrimidine nucleoside salvage pathway. This pathway allows pyrimidine bases to be recycled for nucleotide biosynthesis, while the pentose 1-phosphates are converted to intermediates of the pentose phosphate shunt and glycolysis. The E. coli thymidine phosphorylase shares 40% sequence homology with the human sequence, which has been found to be identical to the angiogenic agent platelet-derived endothelial growth factor. The purified E. coli enzyme has been shown to stimulate blood vessel growth in chick chorioallantoic membrane assays.

Thymidine phosphorylase catalyzes the reversible conversion of thymidine to thymine. Thymidine phosphorylase is part of the thymidine salvage pathway and pyrimidine nucleoside salvage pathway. This pathway allows pyrimidine bases to be recycled for nucleotide biosynthesis, while the pentose 1-phosphates are converted to intermediates of the pentose phosphate shunt and glycolysis. The enzyme inhibits apoptosis and induces angiogenesis thereby promoting tumor growth and metastatic process. Moreover, thymidine phosphorylase inhibits vascular smooth muscle cell proliferation.

Unit Definition

One unit will convert 1.0 μmole each of thymidine and phosphate to thymine and 2-deoxyribose 1-phosphate per min at pH 7.4 at 25°C.

Preparation Note

Cloned from E. coli and produced in overexpressing E. coli