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Michel W Barsoum – One of the best experts on this subject based on the ideXlab platform.

Daniel Hoyer – One of the best experts on this subject based on the ideXlab platform.

David Shugar – One of the best experts on this subject based on the ideXlab platform.

  • interaction of thymidylate synthase with the 5 thiophosphates 5 dithiophosphates 5 h phosphonates and 5 s thiosulfates of 2 deoxyuridine thymidine and 5 fluoro 2 deoxyuridine
    Biological Chemistry, 2001
    Co-Authors: Barbara Golos, Jolanta M Dzik, Z Kazimierczuk, Joanna Ciesla, Zbigniew Zielinski, Jadwiga Jankowska, Adam Kraszewski, Jacek Stawinski, W Rode, David Shugar
    Abstract:

    : New analogs of dUMP, dTMP and 5-fluoro-dUMP, including the corresponding 5‘-thiophosphates (dUMPS, dTMPS and FdUMPS), 5‘-dithiophosphates (dUMPS2, dTMPS2 and FdUMPS2), 5‘-H-phosphonates (dUMP-H, dTMP-H and FdUMP-H) and 5‘-S-thiosulfates (dUSSO3, dTSSO3 and FdUSSO3), have been synthesized and their interactions studied with highly purified mammalian thymidylate synthase. dUMPS and dUMPS2 proved to be good substrates, and dTMPS and dTMPS2 classic competitive inhibitors, only slightly weaker than dTMP. Their 5-fluoro congeners behaved as potent, slow-binding inhibitors. By contrast, the corresponding 5‘-H-phosphonates and 5‘-S-thiosulfates displayed weak activities, only FdUMP-H and FdUSSO3 exhibiting significant interactions with the enzyme, as weak competitive slow-binding inhibitors versus dUMR The pH-dependence of enzyme time-independent inhibition by FdUMP and FdUMPS was found to correlate with the difference in pKa values of the phosphate and thiophosphate groups, the profile of FdUMPS being shifted (approximately 1 pH unit) toward lower pH values, so that binding of dUMP and its analogs is limited by the phosphate secondary hydroxyl ionization. Hence, together with the effects of 5‘-H-phosphonate and 5‘-S-thiosulfate substituents, the much weaker interactions of the nucleotide analogs (3-5 orders of magnitude lower than for the parent 5‘-phosphates) with the enzyme is further evidence that the enzyme’s active center prefers the dianionic phosphate group for optimum binding.

Philippe Schoeffter – One of the best experts on this subject based on the ideXlab platform.

François Durant – One of the best experts on this subject based on the ideXlab platform.

  • 5-(thien-2-yl) uracil analogs: 5-(5-methylthien-2-yl)-2′-deoxyuridine, 5-(5-thien-2-yl)-2′-deoxyuridine, and 5-(5-bromothien-2-yl)-2′-deoxyuridine
    Journal of Chemical Crystallography, 1996
    Co-Authors: Isabelle Creuven, Bernadette Norberg, Anne Olivier, Christine Evrard, Guy Evrard, Piet Wigerinck, Piet Herdewijn, François Durant
    Abstract:

    Crystal structures of 5-(5-methylthien-2-yl)-2′-deoxyuridine (I), 5-(5-thien-2-yl)-2′-deoxyuridine (II) and 5-(5-bromothien-2-yl)-2′-deoxyuridine (III) have been obtained from data collected on a four-circle Enraf-Nonius diffractometer (CAD-4 system). Space group, unit/cell parameters and finalR indices are:I, monoclinic,P21,a=9.105(2),b=20.819(2),c=7.932(2) A, β=98.79(2)°,R=5.7%;II, monoclinic,P21,a=8.720(4),b=20.793(4),c=7.884(4) A, β=95.06(2)°,R=5.8%;III, monoclinic,P21,a=9.260(2),b=41.655(7),c=7.926(2) A, β=97.996(13)°,R=9.4%. Structural properties of the title compounds are compared with those of 5-(5-chlorothien-2-yl)-2′-deoxyuridine (IV) previously reported in order to explain their affinity for HSV-1 thymidine kinase and their eventual interaction with viral DNA polypolymerase. The main structural features observed are the coplanarity of the uracil and thienyl cycles stabilized by a S−O intramolecular interaction and the formation of dimeric intermolecular H bonds between two uracil moieties.