- To explore the potential of the enzyme dUTPase (deoxyuridine triphosphatases) as a target for the development of compounds active against viruses, protozoan parasites (Leishmania, Trypanosoma) and bacteria, and against human neoplastic diseases.
- To investigate dUTPases from the various sources and mutational variants of those with respect to catalytic properties and inhibition with substrate analogues.
- To determine three-dimensional structures of the dUTPases and complexes of structurally determined dUTPases with inhibitory substrate analogues.
- To synthesize and test candidate compounds in rational drug design towards dUTPase inhibitors specifically active against pathogen targets and tumor cells by using enzyme measurements and cell-based assays.
The enzyme dUTPase acts in all classes of dividing cells, and also in certain virus infected cells, to minimise levels of deoxyuridine triphosphate (dUTP). If not removed, dUTP is incorporated into DNA. Inhibition of dUTPase both interrupts supply of thymidine triphosphate (dTTP) for synthesis of DNA and also causes damage to nascent DNA, and so can lead to cell death. dUTPases from different sources show a range of structural and enzymic properties, indicating that it should be feasible to find inhibitory compounds that act differently on the dUTPase of pathogens rather than on the enzyme of the host. dUTPase therefore constitutes an attractive potential target for therapeutic intervention against many infectious agents, and a dUTPase inhibitor might also be suitable for differential action against proliferating human neoplasms.
The proposal sets out plans to advance basic understanding of the dUTPases, and to utilise this information to discover inhibitory substrate analogues. X-ray crystallographic groups in the partnership will work to obtain structures for the dUTPases and for complexes with substrate analogues, building on existing results for the bacterial enzyme. The enzymic characteristics of the dUTPases will be thoroughly investigated, and mutational analyses of their properties will be carried out. Evaluation of substrate analogues as potential inhibitors will first examine selections made from Medivir's existing library of compounds. The effects of compounds on activities of purified enzymes will be analysed. The results of the structural, enzymic and mutational studies, and of the first round of tests on analogues, will build up information about structure/function relationships of dUTPases, to provide the foundation for rational design of inhibitors. Several cycles of design, synthesis and testing of candidate compounds will be performed, to discover inhibitory groupings and then to improve effectiveness and specificity. Assays for the inhibition of growth or killing of cultured tumor cells, bacteria and protozoa will be carried out, and effects on herpesvirus infected cells will be measured.
Funding SchemeCSC - Cost-sharing contracts
G11 5JR Glasgow
401 5DD York