胸苷磷酸化酶，重组 来源于大肠杆菌

一种对胸腺嘧啶可逆性转化为胸腺嘧啶进行催化的酶。 胸苷磷酸化酶是嘧啶核苷挽救途径的一部分。

一种对胸腺嘧啶可逆性转化为胸腺嘧啶进行催化的酶。胸苷磷酸化酶是嘧啶核苷挽救途径的一部分。该途径允许嘧啶碱基被回收用于核苷酸生物合成，而1-磷酸戊糖被转化为磷酸戊糖分流和糖酵解的中间体。 大肠埃希菌胸苷磷酸化酶与人序列具有40%的序列同源性，已发现该序列与血管生成剂血小板衍生的内皮生长因子相同。 在鸡绒膜尿囊膜测定中，纯化的大肠埃希菌酶已显示出刺激血管生长的作用。

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.

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.

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.

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.

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