RESUMEN
Seasonal and pandemic-associated influenza strains cause highly contagious viral respiratory infections that can lead to severe illness and excess mortality. Here, we report on the optimization of our small-molecule inhibitor F0045(S) targeting the influenza hemagglutinin (HA) stem with our Sulfur-Fluoride Exchange (SuFEx) click chemistry-based high-throughput medicinal chemistry (HTMC) strategy. A combination of SuFEx- and amide-based lead molecule diversification and structure-guided design led to identification and validation of ultrapotent influenza fusion inhibitors with subnanomolar EC50 cellular antiviral activity against several influenza A group 1 strains. X-ray structures of six of these compounds with HA indicate that the appended moieties occupy additional pockets on the HA surface and increase the binding interaction, where the accumulation of several polar interactions also contributes to the improved affinity. The compounds here represent the most potent HA small-molecule inhibitors to date. Our divergent HTMC platform is therefore a powerful, rapid, and cost-effective approach to develop bioactive chemical probes and drug-like candidates against viral targets.
Asunto(s)
Antivirales , Glicoproteínas Hemaglutininas del Virus de la Influenza , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Glicoproteínas Hemaglutininas del Virus de la Influenza/química , Humanos , Antivirales/farmacología , Antivirales/química , Química Farmacéutica/métodos , Ensayos Analíticos de Alto Rendimiento/métodos , Gripe Humana/tratamiento farmacológico , Gripe Humana/virología , Cristalografía por Rayos X/métodos , Química Clic/métodos , Animales , Virus de la Influenza A/efectos de los fármacos , Células de Riñón Canino Madin Darby , Inhibidores de Proteínas Virales de Fusión/farmacología , Inhibidores de Proteínas Virales de Fusión/química , PerrosRESUMEN
Accurate diagnosis and effective antiviral treatments are urgently needed for the prevention and control of flu caused by influenza viruses. In this study, a novel oleanic acid (OA) functionalized gold nanorod OA-AuNP was prepared through a convenient ligand-exchange reaction. As hemagglutinin (HA) on the viral surface binds strongly to the multiple OA molecules on the surface of the nanoparticle, the prepared OA-AuNP was found to exhibit potent antiviral activity against a wide range of influenza A virus strains. Furthermore, the change in color resulting from the specific binding between HA and OA and the resultant aggregation of the OA-AuNP can be visually observed or measured by UV-vis spectra with a detection limit of 2 and 0.18 hemagglutination units (HAU), respectively, which is comparable to the commercially available influenza colloid gold rapid diagnostic kits. These findings demonstrate the potential of the OA-AuNP for the development of novel multivalent antiviral conjugates and the diagnosis of influenza virus.
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Antivirales , Oro , Nanotubos , Oro/química , Nanotubos/química , Antivirales/farmacología , Antivirales/química , Virus de la Influenza A/efectos de los fármacos , Humanos , Nanopartículas del Metal/química , Estructura Molecular , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Pruebas de Sensibilidad Microbiana , Perros , Animales , Relación Dosis-Respuesta a Droga , Relación Estructura-ActividadRESUMEN
Influenza (flu) is a serious global health threat. The Hemagglutinin (HA) protein binds the flu virus to the sialic acids at the surface of the host cells' membrane which allows the endocytosis of the virus. Therefore, potential inhibitors can attach to the active site of HA and block the virus life-cycle. In this study, the antiviral drug arbidol (ARB) and 16 HA-subtypes were docked and analyzed to represent different approaches in predicting the conformation of protein-ligand, protein-protein, and protein-glycan complex and its binding energy. Our findings show that ARB interacts with all HA subtypes, and H7 possesses the best affinity. The next influenza pandemic could be caused by H4, H5, H6, and H14 subtypes, which prompts further studies in investigating the interaction between these particular HA subtypes and other antiviral drugs to obtain higher efficacy.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina , Indoles , Antagonistas de Receptores de Angiotensina , HemaglutininasRESUMEN
Influenza hemagglutinin (HA) glycoprotein is the primary surface antigen targeted by the host immune response and a focus for development of novel vaccines, broadly neutralizing antibodies (bnAbs), and therapeutics. HA enables viral entry into host cells via receptor binding and membrane fusion and is a validated target for drug discovery. However, to date, only a very few bona fide small molecules have been reported against the HA. To identity new antiviral lead candidates against the highly conserved fusion machinery in the HA stem, we synthesized a fluorescence-polarization probe based on a recently described neutralizing cyclic peptide P7 derived from the complementarity-determining region loops of human bnAbs FI6v3 and CR9114 against the HA stem. We then designed a robust binding assay compatible with high-throughput screening to identify molecules with low micromolar to nanomolar affinity to influenza A group 1 HAs. Our simple, low-cost, and efficient in vitro assay was used to screen H1/Puerto Rico/8/1934 (H1/PR8) HA trimer against â¼72,000 compounds. The crystal structure of H1/PR8 HA in complex with our best hit compound F0045(S) confirmed that it binds to pockets in the HA stem similar to bnAbs FI6v3 and CR9114, cyclic peptide P7, and small-molecule inhibitor JNJ4796. F0045 is enantioselective against a panel of group 1 HAs and F0045(S) exhibits in vitro neutralization activity against multiple H1N1 and H5N1 strains. Our assay, compound characterization, and small-molecule candidate should further stimulate the discovery and development of new compounds with unique chemical scaffolds and enhanced influenza antiviral capabilities.
Asunto(s)
Antivirales/farmacología , Evaluación Preclínica de Medicamentos/métodos , Polarización de Fluorescencia/métodos , Subtipo H1N1 del Virus de la Influenza A/efectos de los fármacos , Subtipo H5N1 del Virus de la Influenza A/efectos de los fármacos , Gripe Humana/virología , Bibliotecas de Moléculas Pequeñas/farmacología , Antivirales/química , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Humanos , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/metabolismo , Subtipo H5N1 del Virus de la Influenza A/genética , Subtipo H5N1 del Virus de la Influenza A/metabolismo , Bibliotecas de Moléculas Pequeñas/químicaRESUMEN
Infections by H1-H16 influenza A viruses require sufficient binding of viral hemagglutinins (HAs) to specific target receptors, glycoconjugates bearing sialyl sugar chains, on the host cell surface. Synthesized sialyl sugar chains targeting sialyl sugar-binding sites in HAs that are immutable as long as the virus does not switch to a different host species might therefore be highly effective candidate drugs for inhibition of the initial required step of virus entry. In this chapter, we describe the following aspects of updated sialyl sugar chains as influenza A virus HA inhibitors (HAIs): (1) mode of terminal sialyl-galactose linkage, (2) molecular length and structure of sialyl glycan receptors, (3) multivalent sialyl sugar chain dimension, (4) clustering of sialyl sugar chains on macromolecular scaffolds, and (5) enhancement of the stability of sialyl sugar chain HA inhibitors. We also discuss about the use of HAI-based combinations that should be considered for future influenza therapy.
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Antivirales/síntesis química , Glicoconjugados/metabolismo , Hemaglutininas Virales/metabolismo , Virus de la Influenza A/fisiología , Antivirales/química , Antivirales/farmacología , Sitios de Unión/efectos de los fármacos , Desarrollo de Medicamentos , Quimioterapia Combinada , Glicoconjugados/química , Hemaglutininas Virales/química , Humanos , Virus de la Influenza A/efectos de los fármacos , Ácido N-Acetilneuramínico/química , Unión Proteica/efectos de los fármacos , Internalización del Virus/efectos de los fármacosRESUMEN
We report the synthesis of multivalent oleanolic acid (OA) protein conjugates as nonglycosylated neomucin mimic for the capture and entry inhibition of influenza viruses. Oleanolic acid derivatives bearing an amine-terminated linker were synthesized by esterification of carboxylic acid and further grafted onto the human serum albumin (HSA) via diethyl squarate method. The binding of hemagglutinin (HA) on the virion surface to the synthetic neomucin was evaluated by hemagglutination inhibition assay. The influenza virus capture ability of the PEGylated OA-HSA conjugate was further investigated by Dynamic Light Scattering (DLS), virus capture assay and Isothermal Titration Calorimeter (ITC) techniques. The pronounced agglutination of viral particles, the high capture efficiency and affinity constant indicate that this neoprotein is comparable to natural glycosylated mucin, suggesting that this material could potentially be used as anti-infective barriers to prevent virus from invading host cells. The study also rationalizes the feasibility of antiviral drug development based on OA or other antiviral small molecules conjugated protein strategies.
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Antivirales/farmacología , Neomicina/farmacología , Ácido Oleanólico/farmacología , Orthomyxoviridae/efectos de los fármacos , Albúmina Sérica/metabolismo , Antivirales/síntesis química , Antivirales/química , Relación Dosis-Respuesta a Droga , Glicosilación , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Neomicina/síntesis química , Neomicina/química , Ácido Oleanólico/química , Albúmina Sérica/química , Relación Estructura-ActividadRESUMEN
INTRODUCTION: Seasonal influenza and pandemic outbreaks typically result in high mortality and morbidity associated with severe economic burdens. Vaccines and anti-influenza drugs have made great contributions to control the infection. However, antigenic drifts and shifts allow influenza viruses to easily escape immune neutralization and antiviral drug activity. Hemagglutinin (HA)is an important envelope protein for the entry of influenza viruses into host cells, thus, HA-targeted agents may be potential anti-influenza drugs. Areas covered: In this review, we describe arbidol, a unique licensed drug targeting HA; discuss and summarize HA-targeted anti-influenza agents been tested before or being tested currently in clinical trials, including monoclonal antibodies, small molecule inhibitors, proteins and peptides. Other small molecule inhibitors are also briefly introduced. Expert opinion: Exploring new clinical applications for existing drugs can provide additional anti-influenza candidates with promising safety and bioavailability, and largely shortened time and costs. To enhance therapeutic efficacy and avoid drug-resistance, combination therapy involving in HA-targeted anti-influenza agent is reasonable and attractive. For drug discovery, it is helpful to keep an eye on the development of methodology in organic synthesis and probe into the co-crystal structure of HA in complex with small molecule.