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Structural bases of norovirus RNA dependent RNA polymerase inhibition by novel suramin-related compounds. PLoS One 2014; 9:e91765. [PMID: 24622391 PMCID: PMC3951423 DOI: 10.1371/journal.pone.0091765] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 02/14/2014] [Indexed: 11/19/2022] Open
Abstract
Noroviruses (NV) are +ssRNA viruses responsible for severe gastroenteritis; no effective vaccines/antivirals are currently available. We previously identified Suramin (9) as a potent inhibitor of NV-RNA dependent RNA polymerase (NV-RdRp). Despite significant in vitro activities versus several pharmacological targets, Suramin clinical use is hampered by pharmacokinetics/toxicity problems. To improve Suramin access to NV-RdRp in vivo, a Suramin-derivative, 8, devoid of two sulphonate groups, was synthesized, achieving significant anti-human-NV-RdRp activity (IC50 = 28 nM); the compound inhibits also murine NV (mNV) RdRp. The synthesis process led to the isolation/characterization of lower molecular weight intermediates (3-7) hosting only one sulphonate head. The crystal structures of both hNV/mNV-RdRps in complex with 6, were analyzed, providing new knowledge on the interactions that a small fragment can establish with NV-RdRps, and establishing a platform for structure-guided optimization of potency, selectivity and drugability.
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Morgan HP, McNae IW, Nowicki MW, Zhong W, Michels PAM, Auld DS, Fothergill-Gilmore LA, Walkinshaw MD. The trypanocidal drug suramin and other trypan blue mimetics are inhibitors of pyruvate kinases and bind to the adenosine site. J Biol Chem 2011; 286:31232-40. [PMID: 21733839 PMCID: PMC3173065 DOI: 10.1074/jbc.m110.212613] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 06/06/2011] [Indexed: 11/06/2022] Open
Abstract
Ehrlich's pioneering chemotherapeutic experiments published in 1904 (Ehrlich, P., and Shiga, K. (1904) Berlin Klin. Wochenschrift 20, 329-362) described the efficacy of a series of dye molecules including trypan blue and trypan red to eliminate trypanosome infections in mice. The molecular structures of the dyes provided a starting point for the synthesis of suramin, which was developed and used as a trypanocidal drug in 1916 and is still in clinical use. Despite the biological importance of these dye-like molecules, the mode of action on trypanosomes has remained elusive. Here we present crystal structures of suramin and three related dyes in complex with pyruvate kinases from Leishmania mexicana or from Trypanosoma cruzi. The phenyl sulfonate groups of all four molecules (suramin, Ponceau S, acid blue 80, and benzothiazole-2,5-disulfonic acid) bind in the position of ADP/ATP at the active sites of the pyruvate kinases (PYKs). The binding positions in the two different trypanosomatid PYKs are nearly identical. We show that suramin competitively inhibits PYKs from humans (muscle, tumor, and liver isoenzymes, K(i) = 1.1-17 μM), T. cruzi (K(i) = 108 μM), and L. mexicana (K(i) = 116 μM), all of which have similar active sites. Synergistic effects were observed when examining suramin inhibition in the presence of an allosteric effector molecule, whereby IC(50) values decreased up to 2-fold for both trypanosomatid and human PYKs. These kinetic and structural analyses provide insight into the promiscuous inhibition observed for suramin and into the mode of action of the dye-like molecules used in Ehrlich's original experiments.
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Affiliation(s)
- Hugh P. Morgan
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Iain W. McNae
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Matthew W. Nowicki
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Wenhe Zhong
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Paul A. M. Michels
- the Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Université catholique de Louvain, Avenue Hippocrate 74, B-1200 Brussels, Belgium, and
| | - Douglas S. Auld
- the National Institutes of Health Chemical Genomics Center, National Human Genome Research Institute, National Institutes of Health, Rockville, Maryland 20850
| | - Linda A. Fothergill-Gilmore
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Malcolm D. Walkinshaw
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
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