We have studied the effect of pH on the interactions between thymidine kinase, thymidine triphosphate, and 5'-amino-2',5'-dideoxythymidine (S'-Ad'l'hd) in purified preparations of the enzyme and in intact 647V cells, a human bladder cancer cell line. Thymidine kinase is competitively inhibited by S'-AdThd. dI'll' feedback inhibits in a noncompetitive fashion. However, S'-AdThd partially reverse...

We have studied the effect of pH on the interactions between thymidine kinase, thymidine triphosphate, and 5'-amino-2',5'-dideoxythymidine (S'-Ad'l'hd) in purified preparations of the enzyme and in intact 647V cells, a human bladder cancer cell line. Thymidine kinase is competitively inhibited by S'-AdThd. dI'll' feedback inhibits in a noncompetitive fashion. However, S'-AdThd partially reverse...

We have studied the effect of pH on the interactions between thymidine kinase, thymidine triphosphate, and 5'-amino-2',5'-dideoxythymidine (5'-AdThd) in purified preparations of the enzyme and in intact 647V cells, a human bladder cancer cell line. Thymidine kinase is competitively inhibited by 5'-AdThd. dTTP feedback inhibits in a noncompetitive fashion. However, 5'-AdThd partially reverses th...

Variations in the treatment conditions which affect the frequency of BUdR-induced morphogenic lesions in Drosophila melanogaster have been studied. By varying the concentrations of BUdR and FU, or by changing the duration of treatment, it has been demonstrated that increased incorporation of BUdR into DNA results in a concomitant increase in morphogenic lesions. A quantitative analysis of the d...

    Acyclovir (9-[2-hydroxyethoxymethyl] guanine) is an acyclic nucleoside analogue of guanosine which is a potent and selective antiviral agent. Acycloviris converted to the monophosphate by thymidine kinase the virus-specific form of this enzyme and is subsequently converted to the triphosphate by the host cell kinase. Acyclovir triphosphate inhibits viral DNA-polymerase terminating the chain...

Exposure of U-937 cells to 12-O-tetradecanoylphorbol-13-acetate (TPA) resulted in specific alterations in thymidine metabolism. Within 24 h after treatment with 1.62 x 10(-9) M TPA, the reciprocal alteration in the activities of opposing enzymes of thymidine metabolism observed during normal cell culture growth was reversed. In TPA-treated cells, the activities of anabolic enzymes thymidine kin...

The metabolism of 5-fluorouracil (FUra) was examined in two human lymphocyte cell lines, CCRF-CEM (T-leukemic) and LAZ-007 (Epstein-Barr virus-transformed B), which have widely differing FUra sensitivities. CEM cells have orotate phosphoribosyltransferase but no uridine or thymidine phosphorylase activity. Consistent with this, the FUra growth inhibition and the synthesis of fluorouridine triph...

White, P. J. (Roswell Park Memorial Institute, Buffalo, N.Y.) and C. A. Nichol. Effects of uracil and thymidine on the development of resistance to 5-fluorouracil in Pediococcus cerevisiae. J. Bacteriol. 85:97-105. 1963.-Growth of Pediococcus cerevisiae ATCC 8081 in a basal semidefined medium was inhibited by 5-fluorouracil (FU) and 5-fluoro-2'-deoxyuridine (FUDR). Addition of uracil slightly d...