Browsing by Subject "makrodomeeni"

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  • Tervo, Annukka (Helsingfors universitet, 2011)
    Alphaviruses are positive-stranded RNA-viruses and they belong to the family of Togaviridae. Alphaviruses are spread by mosquitoes of family Aedes. Alphaviruses have spread on all continents except Antarctica. So far 29 alphaviral species have been identified and they can be divided in two groups, Old and New world viruses, by their geographical distribution and by diseases they cause. Chikungunya virus (CHIKV) is one of the Old World alphaviruses and it has been found in Africa and Asia. However, due to the global warming, Chikungunya is also spreading to southern Europe. In humans, it causes fever, headache, rash and joint pain, which can last for several years and be very painful. In small children, Chikungunya can cause neurological symptoms such as encephalitis. Genome of alphaviruses encodes for four structural proteins and four non-structural proteins (nsP), of which nsP3 contains a macro domain. Macro domains are conserved in most kingdoms of life but their function has not been elucidated. It has been shown that macro domains bind ADP-ribose and its derivatives and it has been shown that nsP3-protein has an important role in alphavirus replication. The aim of the study was to study the use of compounds which bind to macro domain protein as antiviral agents. 45 compounds were chosen for antiviral studies by molecular modeling. These compounds were expected to bind to macro domain proteins. In a competitive binding assay five compounds inhibited more than 50 % poly-ADP-ribose (PAR) binding to MDO1-macro domain protein, which was the protein on which the molecular modeling was performed. When the competitive binding assay was performed with SFV macro domain (nsP3), only one compound inhibited poly-ADP-ribose binding more than 50 %. In SFV-antiviral assay seven compounds had inhibition percentage higher than 50 %. In a CHIKV replicon assay five compounds had more than 50 % inhibition on replicon expression. We also studied possible inhibition mechanism by studying whether the compounds inhibit the virus to enter the cell. Almost all compounds included in this assay inhibited the virus entry to some extent. In general, the inhibition of PAR binding and antiviral activity did not correlate among the studied compounds. Even though compounds which had antiviral potency did not inhibit PAR binding to macro domains, potential antiviral agents were found which deserve further investigation as virus entry inhibitors.