title: Induction of thymidine kinase and DNase in varicella-zoster virus-infected cells and kinetic properties of the virus-induced thymidine kinase.
abstract: Thymidine kinase (TK), DNA polymerase, and DNase activities were induced in human foreskin fibroblasts after varicella-zoster virus infection. The induced TK and DNase activities have electrophoretic mobilities different from the corresponding host enzymes. Varicella-zoster virus-induced TK was purified and separated from the host enzyme by affinity column chromatography. This enzyme has been shown to have a broader substrate specificity with respect to either the phosphate donor or acceptor as compared with human cytoplasmic and mitochondrial TKs. The best phosphate donor is ATP, with a Km of 16 microM. The Km values of thymidine, deoxycytidine, and 5-propyl deoxyuridine were estimated to be 0.4, 180, and 0.8 microM, respectively. The Ki values for several analogs of thymidine such as 5-iododeoxyuridine, arabinofuranosylthymine, 5-ethyl deoxyuridine, and 5-cyanodeoxyuridine were also examined. TTP acted as a noncompetitive inhibitor with respect to thymidine with a Ki of 5 microM. The kinetic behavior of varicella-zoster virus-induced TK is different from human cytoplasmic, human mitochondrial, and herpes simplex virus type 1- and 2-induced TKs.
mesh_terms: D002460:Cell Line; D004259:DNA-Directed DNA Polymerase / Q000096:biosynthesis; D003851:Deoxyribonucleases / Q000096:biosynthesis*; D004790:Enzyme Induction; D005347:Fibroblasts; D014645:Herpesvirus 3, Human / Q000201:enzymology* / Q000254:growth & development; D006801:Humans; D007700:Kinetics; D009711:Nucleotides / Q000378:metabolism; D012867:Skin; D013379:Substrate Specificity; D013937:Thymidine Kinase / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000378:metabolism
chemical_list: D009711:Nucleotides; D013937:Thymidine Kinase; D004259:DNA-Directed DNA Polymerase; D003851:Deoxyribonucleases