title: Purification and Biochemical Characterisation of Rabbit Calicivirus RNA-Dependent RNA Polymerases and Identification of Non-Nucleoside Inhibitors.
abstract: Rabbit haemorrhagic disease virus (RHDV) is a calicivirus that causes acute infections in both domestic and wild European rabbits (Oryctolagus cuniculus). The virus causes significant economic losses in rabbit farming and reduces wild rabbit populations. The recent emergence of RHDV variants capable of overcoming immunity to other strains emphasises the need to develop universally effective antivirals to enable quick responses during outbreaks until new vaccines become available. The RNA-dependent RNA polymerase (RdRp) is a primary target for the development of such antiviral drugs. In this study, we used cell-free in vitro assays to examine the biochemical characteristics of two rabbit calicivirus RdRps and the effects of several antivirals that were previously identified as human norovirus RdRp inhibitors. The non-nucleoside inhibitor NIC02 was identified as a potential scaffold for further drug development against rabbit caliciviruses. Our experiments revealed an unusually high temperature optimum (between 40 and 45 °C) for RdRps derived from both a pathogenic and a non-pathogenic rabbit calicivirus, possibly demonstrating an adaptation to a host with a physiological body temperature of more than 38 °C. Interestingly, the in vitro polymerase activity of the non-pathogenic calicivirus RdRp was at least two times higher than that of the RdRp of the highly virulent RHDV.
authors.affiliation: Commonwealth Scinetific and Industrial Research Organisation, Health and Biosecurity, 2601 Canberra, ACT, Australia. nadezda.urakova@csiro.au.|Invasive Animals Cooperative Research Centre, University of Canberra, 2617 Canberra, ACT, Australia. nadezda.urakova@csiro.au.|Health Research Institute, University of Canberra, 2617 Canberra, ACT, Australia. nadezda.urakova@csiro.au.
authors.forename: Nadya
authors.initials: N
authors.lastname: Urakova
authors.affiliation: School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, 2052 Sydney, NSW, Australia. n.netzler@unsw.edu.au.
authors.forename: Natalie
authors.initials: N
authors.lastname: Netzler
authors.affiliation: School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, 2052 Sydney, NSW, Australia. agk22000@gmail.com.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Kelly
authors.affiliation: Commonwealth Scinetific and Industrial Research Organisation, Health and Biosecurity, 2601 Canberra, ACT, Australia. michael.frese@canberra.edu.au.|Invasive Animals Cooperative Research Centre, University of Canberra, 2617 Canberra, ACT, Australia. michael.frese@canberra.edu.au.|Health Research Institute, University of Canberra, 2617 Canberra, ACT, Australia. michael.frese@canberra.edu.au.|Institute for Applied Ecology, University of Canberra, 2617 Canberra, ACT, Australia. michael.frese@canberra.edu.au.
authors.forename: Michael
authors.initials: M
authors.lastname: Frese
authors.affiliation: School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, 2052 Sydney, NSW, Australia. p.white@unsw.edu.au.
authors.forename: Peter A
authors.initials: PA
authors.lastname: White
authors.affiliation: Commonwealth Scinetific and Industrial Research Organisation, Health and Biosecurity, 2601 Canberra, ACT, Australia. tanja.strive@csiro.au.|Invasive Animals Cooperative Research Centre, University of Canberra, 2617 Canberra, ACT, Australia. tanja.strive@csiro.au.|Institute for Applied Ecology, University of Canberra, 2617 Canberra, ACT, Australia. tanja.strive@csiro.au.
authors.forename: Tanja
authors.initials: T
authors.lastname: Strive
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D017250:Caliciviridae Infections / Q000188:drug therapy / Q000821:virology; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery; D004789:Enzyme Activation / Q000187:drug effects; D019143:Evolution, Molecular; D015870:Gene Expression; D017929:Hemorrhagic Disease Virus, Rabbit / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D020128:Inhibitory Concentration 50; D007700:Kinetics; D012324:RNA-Dependent RNA Polymerase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins; D011995:Recombination, Genetic
chemical_list: D000998:Antiviral Agents; D011993:Recombinant Fusion Proteins; D012324:RNA-Dependent RNA Polymerase
keywords: RCV-A1; RHDV; antiviral agents; non-nucleoside inhibitors; polymerase