63302 20171129112117.0 doi 10.1371/journal.pone.0069773 sideral 82460 ART-2013-82460 eng (orcid)0000-0001-5664-1729 Abian, O. Universidad de Zaragoza Allosteric Inhibitors of the NS3 Protease from the Hepatitis C Virus 2013 Access copy available to the general public Unrestricted The nonstructural protein 3 (NS3) from the hepatitis C virus processes the non-structural region of the viral precursor polyprotein in infected hepatic cells. The NS3 protease activity has been considered a target for drug development since its identification two decades ago. Although specific inhibitors have been approved for clinical therapy very recently, resistance-associated mutations have already been reported for those drugs, compromising their long-term efficacy. Therefore, there is an urgent need for new anti-HCV agents with low susceptibility to resistance-associated mutations. Regarding NS3 protease, two strategies have been followed: competitive inhibitors blocking the active site and allosteric inhibitors blocking the binding of the accessory viral protein NS4A. In this work we exploit the intrinsic Zn+2-regulated plasticity of the protease to identify a new type of allosteric inhibitors. In the absence of Zn+2, the NS3 protease adopts a partially-folded inactive conformation. We found ligands binding to the Zn+2-free NS3 protease, trap the inactive protein, and block the viral life cycle. The efficacy of these compounds has been confirmed in replicon cell assays. Importantly, direct calorimetric assays reveal a low impact of known resistance-associated mutations, and enzymatic assays provide a direct evidence of their inhibitory activity. They constitute new low molecular-weight scaffolds for further optimization and provide several advantages: 1) new inhibition mechanism simultaneously blocking substrate and cofactor interactions in a non-competitive fashion, appropriate for combination therapy; 2) low impact of known resistance-associated mutations; 3) inhibition of NS4A binding, thus blocking its several effects on NS3 protease. info:eu-repo/grantAgreement/ES/DGA/B01 info:eu-repo/grantAgreement/ES/DGA/B89 info:eu-repo/grantAgreement/ES/DGA/PI044-09 info:eu-repo/grantAgreement/ES/FIS/PI10-00186 info:eu-repo/grantAgreement/ES/MICINN/BFU2010-16297 info:eu-repo/grantAgreement/ES/MICINN/BFU2010-19451 info:eu-repo/grantAgreement/ES/MICINN/PTA2009-2341-I info:eu-repo/grantAgreement/ES/UZ/UZ2009-BIO-05 info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 3.534 2013 MULTIDISCIPLINARY SCIENCES 8 / 56 = 0.143 2013 Q1 T1 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion (orcid)0000-0002-1232-6310 Vega, S. (orcid)0000-0002-2879-9200 Sancho, J. Universidad de Zaragoza (orcid)0000-0001-5702-4538 Velazquez-Campoy, A. Universidad de Zaragoza 1002 060 Universidad de Zaragoza Departamento de Bioquímica y Biología Molecular y Celular Bioquímica y Biología Molecular 8, 7 (2013), e69773 [10 pp] PLoS One PLoS One 1932-6203 356256 http://zaguan.unizar.es/record/63302/files/texto_completo.pdf Versión publicada 126536 http://zaguan.unizar.es/record/63302/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:63302 articulos driver 2017-11-28-12:46:09 ARTICLE