Interaction of the recombinant Herpes Simplex Virus type 1 thymidine kinase with thymidine and aciclovir: A kinetic study

Herpes Simplex Virus type 1 thymidine kinase (HSV 1 TK) is a key target for antiviral therapy and it phosphorylates a broad spectrum of nucleosides an d nucleotides. We report the results from kinetic and inhibition experiment s with HSV 1 TK, and show that there is a preferred, but not exclusive, bin ding order of substrates, i.e. dT binds prior to ATP. Furthermore, the resu lts provide new informations on the mechanism of binding suggesting that HS V 1 TK undergoes conformational changes during the catalytic cycle.