Experimental and structural evidence that herpes 1 kinase and cellular DNA polymerase(s) discriminate on the basis of sugar pucker

J Am Chem Soc. 2004 Jan 21;126(2):543-9. doi: 10.1021/ja037929e.


Two isomers of methanocarba (MC) thymidine (T), one an effective antiherpes agent with the pseudosugar moiety locked in the North (N) hemisphere of the pseudorotational cycle (1a, N-MCT) and the other an inactive isomer locked in the antipodean South (S) conformation (1b, S-MCT) were used to determine whether kinases and polymerases discriminate between their substrates on the basis of sugar conformation. A combined solid-state and solution conformational analysis of both compounds, coupled with the direct measurement of mono-, di-, and triphosphate levels in control cells, cells infected with the Herpes simplex virus, or cells transfected with the corresponding viral kinase gene (HSV-tk), suggests that kinases prefer substrates that adopt the S sugar conformation. On the other hand, the cellular DNA polymerase(s) of a murine tumor cell line transfected with HSV-tk incorporated almost exclusively the triphosphate of the locked N conformer (N-MCTTP), notwithstanding the presence of higher triphosphate levels of the S-conformer (S-MCTTP).

MeSH terms

  • Animals
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / metabolism
  • Antineoplastic Agents / pharmacology
  • Antiviral Agents / chemistry
  • Antiviral Agents / metabolism
  • Antiviral Agents / pharmacology
  • Cell Line, Tumor
  • Chlorocebus aethiops
  • DNA / metabolism
  • DNA-Directed DNA Polymerase / chemistry
  • DNA-Directed DNA Polymerase / metabolism*
  • Herpesvirus 1, Human / enzymology*
  • Herpesvirus 1, Human / genetics
  • Mice
  • Models, Molecular
  • Molecular Conformation
  • Nuclear Magnetic Resonance, Biomolecular
  • Structure-Activity Relationship
  • Substrate Specificity
  • Thymidine / analogs & derivatives*
  • Thymidine / chemistry
  • Thymidine / metabolism*
  • Thymidine / pharmacology*
  • Thymidine Kinase / chemistry
  • Thymidine Kinase / genetics
  • Thymidine Kinase / metabolism*
  • Transfection
  • Vero Cells


  • Antineoplastic Agents
  • Antiviral Agents
  • DNA
  • Thymidine Kinase
  • DNA-Directed DNA Polymerase
  • (north)-methanocarbathymidine
  • Thymidine