Partial Purification of a Thymidine Phosphorylase from Human Gastric Cancer

• Published in: Chemical & pharmaceutical bulletin Vol. 34; no. 3; pp. 1219 - 1222
• Main Authors: SUGATA, SETSURO, KONO, AKIRA, HARA, YASUHIRO, KARUBE, YOSHIHARU, MATSUSHIMA, YOSHIKAZU
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 1986; Maruzen; Japan Science and Technology Agency
• Subjects: 1-(tetrahydro-2-furanyl)-5-fluorouracil; Applied sciences; Biological and medical sciences; carcinoma; Exact sciences and technology; Floxuridine - pharmacology; Gastroenterology. Liver. Pancreas. Abdomen; Humans; In Vitro Techniques; man; Medical sciences; Other techniques and industries; Pentosyltransferases - isolation & purification; stomach; Stomach Neoplasms - enzymology; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Thymidine - metabolism; thymidine phosphorylase; Thymidine Phosphorylase - isolation & purification; Thymidine Phosphorylase - metabolism; Tumors; Uridine - metabolism; Stomach; Tumor; Enzymatic activity; Thymidine phosphorylase
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.34.1219

A thymidine phosphorylase (TP) preparation was partially purified from human gastric cancer (poorly differentiated adenocarcinoma). The specific activity of the final preparation represented a 379-fold purification of the 7000g supernatant of tissue homogenate. The phosphorolytic activities toward thymidine (dThd), 5'-deoxy-5-fluorouridine (5'-DFUR), and 1-(tetrahydro-2-furanyl)-5-fluorouracil (Tegafur) remained closely in parallel during the whole purification procedure. The results provide evidence in support of the assumption that 5'-DFUR and Tegafur are converted into 5-fluorouracil, an activated form of the antitumor agents, in humn tumor tissues by a TP activity. The values of Km of the TP preparation were 1.68×10-4, 1.72×10-3, 1.33×10-2, and 4.76×10-2M for dThd, 5'-DFUR, Tegafur, and uridine, respectively.