The work described in this thesis was aimed at distinguishing between two possible mechanisms for the antiviral mode of action of pyrophosphate analogues. Either, (a) they are converted into analogues of nucleoside triphosphates which inhibit the viral polymerase, or (b) they interact directly with the polymerase possibly by coordinating with an essential metal ion. Several pyrophosphate analogues have been synthesised and screened for activity against herpesvirus DNA polymerase, influenza RNA polymerase and calf thymus DNA polymerase a. Characterisation of a number of these compounds was accomplished by chemical ionisation mass spectrometry. A number of reagent gases were tested and ammonia was found to be the most satisfactory. The work carried out in this thesis suggests that the pyrophosphate analogues do not inhibit the viral polymerases by first being incorporated into the 6-y positions of nucleoside triphosphates. The proposed nucleoside triphosphate analogues have been synthesised and these are neither substrates for, nor inhibitors of the enzymes. Furthermore, when [2-^H] -phosphonoacetate was incubated with the standard polymerase assay mixtures, all the radioactivity recovered from the assays was in the form of starting material, none could be detected in the form of nucleoside triphosphate analogues. However, it appears that the pyrophosphate analogues complex with an essential metal ion of influenza RNA polymerase. Dissociation constants (Kd i) for complexes formed between zinc ions and pyrophosphate analogues at pH 8.0 have been determined by gel filtration and there is a correlation between the Kd i of an analogue and its effectiveness as an inhibitor of influenza RNA polymerase.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:253433 |
| Date | January 1983 |
| Creators | Cload, Paul Andrew |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/106482/ |
Page generated in 0.0015 seconds