The Use of Alphavirus Protease for Inhibition of Virus Replication

Abstract

Alphaviruses are positive-strand RNA viruses, 12 kb in length, belonging to Togaviridae family. They are transmitted through arthropod vectors, can infect humans, and cause various of diseases. Structurally, they consist of two ORFs, one of which encodes four non-structural proteins that serve as viral replication machinery. Another ORF encodes three structural proteins. Studying the process of correct proteolytic processing of non-structural polyprotein which leads to production of nsPs is crucial for alphavirus replication life cycle. Alphaviral nsP2 protease has diverse functions including regulation of cleavages within the polyprotein and inhibition of cellular activities. The main aim of the thesis was the investigation of the inhibitory effect of six different versions of singleresidue substitutions in SINV nsP2 protease to SINV-specific template/replicase RNAs as well as the inhibitory level of SINV nsP2 proteases on replication of different Alphaviruses. According to the results the SINV nsP2 N614D mutant was the strongest inhibitor among other six versions of SINV nspP2 tested, but the inhibition level of other mutants of SINV nsP2 on other Alphaviruses replication was not prominent. Neither vaccine nor antiviral therapy against Alphaviruses is available up to date, together with its frequent incidence of outbreaks have emphasized the necessity to study Alphaviruses. Current study can give an insight into the most important aspects of its replication and give a possibility to use this knowledge in order to elaborate different approaches for antiviral therapy.