title: Parallel screening of wild-type and drug-resistant targets for anti-resistance neuraminidase inhibitors.
abstract: Infection with influenza virus is a major public health problem, causing serious illness and death each year. Emergence of drug-resistant influenza virus strains limits the effectiveness of drug treatment. Importantly, a dual H275Y/I223R mutation detected in the pandemic influenza A 2009 virus strain results in multidrug resistance to current neuraminidase (NA) drugs. Therefore, discovery of new agents for treating multiple drug-resistant (MDR) influenza virus infections is important. Here, we propose a parallel screening strategy that simultaneously screens wild-type (WT) and MDR NAs, and identifies inhibitors matching the subsite characteristics of both NA-binding sites. These may maintain their potency when drug-resistant mutations arise. Initially, we analyzed the subsite of the dual H275Y/I223R NA mutant. Analysis of the site-moiety maps of NA protein structures show that the mutant subsite has a relatively small volume and is highly polar compared with the WT subsite. Moreover, the mutant subsite has a high preference for forming hydrogen-bonding interactions with polar moieties. These changes may drive multidrug resistance. Using this strategy, we identified a new inhibitor, Remazol Brilliant Blue R (RB19, an anthraquinone dye), which inhibited WT NA and MDR NA with IC(50) values of 3.4 and 4.5 µM, respectively. RB19 comprises a rigid core scaffold and a flexible chain with a large polar moiety. The former interacts with highly conserved residues, decreasing the probability of resistance. The latter forms van der Waals contacts with the WT subsite and yields hydrogen bonds with the mutant subsite by switching the orientation of its flexible side chain. Both scaffolds of RB19 are good starting points for lead optimization. The results reveal a parallel screening strategy for identifying resistance mechanisms and discovering anti-resistance neuraminidase inhibitors. We believe that this strategy may be applied to other diseases with high mutation rates, such as cancer and human immunodeficiency virus type 1.
authors: Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan.
authors: Kai-Cheng
authors: KC
authors: Hsu
authors: Hui-Chen
authors: HC
authors: Hung
authors: Jim-Tong
authors: JT
authors: Horng
authors: Ming-Yu
authors: MY
authors: Fang
authors: Chun-Yu
authors: CY
authors: Chang
authors: Ling-Ting
authors: LT
authors: Li
authors: I-Jung
authors: IJ
authors: Chen
authors: Yun-Chu
authors: YC
authors: Chen
authors: Ding-Li
authors: DL
authors: Chou
authors: Chun-Wei
authors: CW
authors: Chang
authors: Hsing-Pang
authors: HP
authors: Hsieh
authors: Jinn-Moon
authors: JM
authors: Yang
authors: John T-A
authors: JT
authors: Hsu
mesh_terms: D000880:Anthraquinones / Q000008:administration & dosage / Q000737:chemistry; D000998:Antiviral Agents; D018432:Drug Resistance, Multiple / Q000235:genetics; D024882:Drug Resistance, Viral / Q000235:genetics*; D005838:Genotype; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics* / Q000472:pathogenicity; D007251:Influenza, Human / Q000188:drug therapy* / Q000235:genetics* / Q000821:virology; D009154:Mutation; D009439:Neuraminidase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D058873:Pandemics
chemical_list: D000880:Anthraquinones; D000998:Antiviral Agents; D009439:Neuraminidase; C024758:Remazol Brilliant Blue R