title: Synthesis, crystal structure, and in vitro biological evaluation of C-6 pyrimidine derivatives: new lead structures for monitoring gene expression in vivo.
abstract: Novel C-6 substituted pyrimidine derivatives are good substrates of herpes simplex virus type 1 thymidine kinase (HSV1-TK). Enzyme kinetic experiments showed that our lead compound, N-methyl DHBT (N-methyl-6-(1,3-dihydroxyisobutyl) thymine; N-Me DHBT), is phosphorylated at a similar rate compared to "gold standard" 9-[4-fluoro-3-(hydroxymethyl)butyl]guanine, FHBG, (K(m) = 10 ± 0.3 μM; k(cat) = 0.036 ± 0.015 sec(-1)). Additionally, it does not show cytotoxic properties on B16F1 cells up to a concentration of 10 mM. The x-ray analysis of the crystal structures of HSV1-TK with N-Me DHBT and of HSV1-TK with the fluorinated derivative N-Me FHBT confirmed the binding mode predicted by docking studies and their substrate characteristics. Moreover, the crystal structure of HSV1-TK with N-Me DHBT revealed an additional water-mediated H-bond interesting for the design of further analogues.
authors.affiliation: Center for Pharmaceutical Science of ETH, PSI and USZ, ETH Zurich, Zurich, Switzerland.
authors.forename: Miljen
authors.initials: M
authors.lastname: Martić
authors.forename: Lucile
authors.initials: L
authors.lastname: Pernot
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Westermaier
authors.forename: Remo
authors.initials: R
authors.lastname: Perozzo
authors.forename: Tatjana Gazivoda
authors.initials: TG
authors.lastname: Kraljević
authors.forename: Svjetlana
authors.initials: S
authors.lastname: Krištafor
authors.forename: Silvana
authors.initials: S
authors.lastname: Raić-Malić
authors.forename: Leonardo
authors.initials: L
authors.lastname: Scapozza
authors.forename: Simon
authors.initials: S
authors.lastname: Ametamey
mesh_terms: D000818:Animals; D055162:Biocatalysis; D020134:Catalytic Domain; D045744:Cell Line, Tumor; D018360:Crystallography, X-Ray; D015870:Gene Expression / Q000187:drug effects*; D054879:Halogenation; D018259:Herpesvirus 1, Human / Q000201:enzymology; D006801:Humans; D008745:Methylation; D051379:Mice; D008958:Models, Molecular; D011687:Purines / Q000737:chemistry / Q000378:metabolism; D015203:Reproducibility of Results; D013379:Substrate Specificity; D013937:Thymidine Kinase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013941:Thymine / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D014161:Transduction, Genetic
chemical_list: D011687:Purines; D013937:Thymidine Kinase; D013941:Thymine