title: 5-Bromovinyl 2'-deoxyuridine phosphorylation by mitochondrial and cytosolic thymidine kinase (TK2 and TK1) and its use in selective measurement of TK2 activity in crude extracts.
abstract: Mitochondrial thymidine kinase (TK2) is responsible for phosphorylation of thymidine and deoxycytidine and plays a crucial role in mitochondrial DNA precursor synthesis. TK2 is expressed in all tissues at low levels complicating accurate determinations, especially in tissues with high cytosolic thymidine kinase (TK1) activity. Recently, 5-bromovinyl 2 '-deoxyuridine (BvdU) at 0.2 micro M was used to measure TK2 activity selectively. BvdU phosphorylation by pure human TK2 and TK1 was tested here, and the ratio of BvdU phosphorylation by TK2/TK1 was 91 at 0.2 micro M but was 500 at 2.5 micro M. Therefore, for reliable measurement of TK2 activity higher BvdU concentration should be used.
authors.affiliation: Department of Anatomy, Physiology and Biochemistry, Section of Veterinary Medical Biochemistry, Swedish University of Agricultural Sciences, The Biomedical Centre, Uppsala, Sweden.
authors.forename: Liya
authors.initials: L
authors.lastname: Wang
authors.forename: Staffan
authors.initials: S
authors.lastname: Eriksson
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000031:analogs & derivatives* / Q000378:metabolism; D045424:Complex Mixtures / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D051379:Mice; D008928:Mitochondria / Q000201:enzymology*; D009928:Organ Specificity; D010766:Phosphorylation; D013379:Substrate Specificity; D013936:Thymidine / Q000378:metabolism; D013937:Thymidine Kinase / Q000378:metabolism*; D013939:Thymidine Phosphorylase / Q000037:antagonists & inhibitors
chemical_list: D045424:Complex Mixtures; D004791:Enzyme Inhibitors; C020235:brivudine; D013939:Thymidine Phosphorylase; C105339:thymidine kinase 2; D013937:Thymidine Kinase; C092717:thymidine kinase 1; D001973:Bromodeoxyuridine; D013936:Thymidine