1
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Teramoto T, Choi KH, Padmanabhan R. Flavivirus proteases: The viral Achilles heel to prevent future pandemics. Antiviral Res 2023; 210:105516. [PMID: 36586467 PMCID: PMC10062209 DOI: 10.1016/j.antiviral.2022.105516] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 12/31/2022]
Abstract
Flaviviruses are important human pathogens and include dengue (DENV), West Nile (WNV), Yellow fever virus (YFV), Japanese encephalitis (JEV) and Zika virus (ZIKV). DENV, transmitted by mosquitoes, causes diseases ranging in severity from mild dengue fever with non-specific flu-like symptoms to fatal dengue hemorrhagic fever and dengue shock syndrome. DENV infections are caused by four serotypes, DENV1-4, which interact differently with antibodies in blood serum. The incidence of DENV infection has increased dramatically in recent decades and the CDC estimates 400 million dengue infections occur each year, resulting in ∼25,000 deaths mostly among children and elderly people. Similarly, ZIKV infections are caused by infected mosquito bites to humans, can be transmitted sexually and through blood transfusions. If a pregnant woman is infected, the virus can cross the placental barrier and can spread to her fetus, causing severe brain malformations in the child including microcephaly and other birth defects. It is noteworthy that the neurological manifestations of ZIKV were also observed in DENV endemic regions, suggesting that pre-existing antibody response to DENV could augment ZIKV infection. WNV, previously unknown in the US (and known to cause only mild disease in Middle East), first arrived in New York city in 1999 (NY99) and spread throughout the US and Canada by Culex mosquitoes and birds. WNV is now endemic in North America. Thus, emerging and re-emerging flaviviruses are significant threat to human health. However, vaccines are available for only a limited number of flaviviruses, and antiviral therapies are not available for any flavivirus. Hence, there is an urgent need to develop therapeutics that interfere with essential enzymatic steps, such as protease in the flavivirus lifecycle as these viruses possess significant threat to future pandemics. In this review, we focus on our E. coli expression of NS2B hydrophilic domain (NS2BH) covalently linked to NS3 protease domain (NS3Pro) in their natural context which is processed by the combined action of both subunits of the NS2B-NS3Pro precursor. Biochemical activities of the viral protease such as solubility and autoproteolysis of NS2BH-NS3Pro linkage depended on the C-terminal portion of NS2BH linked to the NS3Pro domain. Since 2008, we also focus on the use of the recombinant protease in high throughput screens and characterization of small molecular compounds identified in these screens.
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Affiliation(s)
- Tadahisa Teramoto
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, 20057, USA.
| | - Kyung H Choi
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, 47406, USA.
| | - Radhakrishnan Padmanabhan
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, 20057, USA.
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2
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Chauhan R, Chauhan Kushwah V, Agnihotri S, Vimal M, Saxena N, Dhaked RK. Designing, synthesis and evaluation of derived analogues of selected small molecule non-peptidic inhibitors against serotype BoNT/ F. Toxicon 2023; 222:106981. [PMID: 36503896 DOI: 10.1016/j.toxicon.2022.106981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 11/04/2022] [Accepted: 11/18/2022] [Indexed: 11/27/2022]
Abstract
Botulinum neurotoxins are lethal Biowarfare categorized in group A of selected agents, by CDC USA. The unavailability of counter-measures against these neurotoxins has been a matter of extensive research. The 8-hydroxyquinoline (8-HQ) scaffold is established privileged compound and its potential as drug candidate against BoNTs is recently being explored. We have reported 8-HQ compounds NSC1014 and NSC1011 as potential small molecule inhibitors against BoNT/F. In the present study, analogues of NSC84087 and NSC1014 were designed, synthesized and studied for their inhibitory role against BoNT/F intoxication through in silico study, in vitro and in-vivo assays. ∼25 in-house synthesized small molecule inhibitors were evaluated against rBoNT/F light chain through fluorescence thermal shift (FTS) assay and then further assessed through endopeptidase assay. The binding affinity analysis was done through surface plasmon resonance (SPR) based Proteon™ XPR 36 system. Finally, the in-vivo efficacy of these compounds was evaluated in mice model. Analogues C87.9, C87.10 and C87.12 of compound NSC84087 and C14.10, C14.11 and C14.13 of NSC1014 showed promising results through FTS assay and endopeptidase assay. SPR based protein-small molecule interaction studies showed KD values in sub-micromolar range signifying high affinity interaction. The IC50 of C14.10 was found to be the lowest of 3.016 ± 0.798 μM as determined through endopeptidase assay. Finally, efficacy of selected molecules was evaluated in mice, C14.10 and C14.13 protected 40% animals against 4X LD50 and extended survival time up to 200% at 10X LD50. The present study thus proposes the emergence of NSC84087 and NSC1014 analogues as lead compound against BoNT/F.
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Affiliation(s)
- Ritika Chauhan
- Biotechnology Division, Defence Research & Development Establishment, Jhansi Road, Gwalior, 474002, MP, India
| | - Vinita Chauhan Kushwah
- Biotechnology Division, Defence Research & Development Establishment, Jhansi Road, Gwalior, 474002, MP, India
| | - Surabhi Agnihotri
- Biotechnology Division, Defence Research & Development Establishment, Jhansi Road, Gwalior, 474002, MP, India
| | - Manorama Vimal
- Synthetic Chemistry Division, Defence Research & Development Establishment, Jhansi Road, Gwalior, 474002, MP, India
| | - Nandita Saxena
- Pharmacology and Toxicology Division, Defence Research & Development Establishment, Jhansi Road, Gwalior, 474002, MP, India
| | - Ram Kumar Dhaked
- Biotechnology Division, Defence Research & Development Establishment, Jhansi Road, Gwalior, 474002, MP, India.
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3
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Voss S, Nitsche C. Targeting the protease of West Nile virus. RSC Med Chem 2021; 12:1262-1272. [PMID: 34458734 PMCID: PMC8372202 DOI: 10.1039/d1md00080b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/17/2021] [Indexed: 01/04/2023] Open
Abstract
West Nile virus infections can cause severe neurological symptoms. During the last 25 years, cases have been reported in Asia, North America, Africa, Europe and Australia (Kunjin). No West Nile virus vaccines or specific antiviral therapies are available to date. Various viral proteins and host-cell factors have been evaluated as potential drug targets. The viral protease NS2B-NS3 is among the most promising viral targets. It releases viral proteins from a non-functional polyprotein precursor, making it a critical factor of viral replication. Despite strong efforts, no protease inhibitors have reached clinical trials yet. Substrate-derived peptidomimetics have facilitated structural elucidations of the active protease state, while alternative compounds with increased drug-likeness have recently expanded drug discovery efforts beyond the active site.
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Affiliation(s)
- Saan Voss
- Research School of Chemistry, Australian National University Canberra ACT 2601 Australia
| | - Christoph Nitsche
- Research School of Chemistry, Australian National University Canberra ACT 2601 Australia
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4
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Islamuddin M, Afzal O, Khan WH, Hisamuddin M, Altamimi ASA, Husain I, Kato K, Alamri MA, Parveen S. Inhibition of Chikungunya Virus Infection by 4-Hydroxy-1-Methyl-3-(3-morpholinopropanoyl)quinoline-2(1 H)-one (QVIR) Targeting nsP2 and E2 Proteins. ACS OMEGA 2021; 6:9791-9803. [PMID: 33869959 PMCID: PMC8047676 DOI: 10.1021/acsomega.1c00447] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
The re-emergence of Chikungunya virus (CHIKV) infection in humans with no approved antiviral therapies or vaccines is one of the major problems with global significance. In the present investigation, we screened 80 in-house quinoline derivatives for their anti-CHIKV activity by computational techniques and found 4-hydroxy-1-methyl-3-(3-morpholinopropanoyl)quinoline-2(1H)-one (QVIR) to have potential binding affinities with CHIKV nsP2 and E2 glycoproteins. QVIR was evaluated in vitro for its anti-CHIKV potential. QVIR showed strong inhibition of CHIKV infection with an EC50 (50% effective concentration) value of 2.2 ± 0.49 μM without significant cytotoxicity (CC50 > 200 μM) and was chosen for further elucidation of its antiviral mechanism. The infectious viral particle formation was abolished by approximately 72% at a QVIR concentration of 20 μM during infection in the BHK-21 cell line, and the CHIKV RNA synthesis was diminished by 84% for nsP2 as well as 74% for E2, whereas the levels of viral proteins were decreased by 69.9% for nsP2 and 53.9% for E2. Flow cytometry analysis confirmed a huge decline in the expression of viral nsP2 and E2 proteins by 71.84 and 67.7%, respectively. Time of addition experiments indicated that QVIR inhibited viral infection at early and late stages of viral replication cycle, and the optimal inhibition was observed at 16 h post infection. The present study advocates for the first time that QVIR acts as a substantial and potent inhibitor against CHIKV and might be as an auspicious novel drug candidate for the development of therapeutic agents against CHIKV infections.
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Affiliation(s)
- Mohammad Islamuddin
- Molecular
Virology Laboratory, Centre for Interdisciplinary Research in Basic
Sciences, Jamia Millia Islamia, New Delhi 110025, India
- Laboratory
of Sustainable Animal Environment, Graduate School of Agricultural
Science, Tohoku University, Osaki, Miyagi 989-6711, Japan
| | - Obaid Afzal
- Department
of Pharmaceutical Chemistry, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al Kharj 11942, Saudi Arabia
| | - Wajihul Hasan Khan
- Kusuma
School of Biological Sciences, Indian Institute
of Technology (IIT), New Delhi 110016, India
| | - Malik Hisamuddin
- Molecular
Virology Laboratory, Centre for Interdisciplinary Research in Basic
Sciences, Jamia Millia Islamia, New Delhi 110025, India
| | | | - Ibraheem Husain
- Department
of Pharmacology, School of Pharmaceutical and Research, Hamdard University, New Delhi 110062, India
| | - Kentaro Kato
- Laboratory
of Sustainable Animal Environment, Graduate School of Agricultural
Science, Tohoku University, Osaki, Miyagi 989-6711, Japan
| | - Mubarak A. Alamri
- Department
of Pharmaceutical Chemistry, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al Kharj 11942, Saudi Arabia
| | - Shama Parveen
- Molecular
Virology Laboratory, Centre for Interdisciplinary Research in Basic
Sciences, Jamia Millia Islamia, New Delhi 110025, India
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Asiri YI, Alsayari A, Muhsinah AB, Mabkhot YN, Hassan MZ. Benzothiazoles as potential antiviral agents. J Pharm Pharmacol 2020; 72:1459-1480. [PMID: 32705690 PMCID: PMC7405065 DOI: 10.1111/jphp.13331] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/03/2020] [Accepted: 06/13/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The recent viral pandemic poses a unique challenge for healthcare providers. Despite the remarkable progress, the number of novel antiviral agents in the pipeline is woefully inadequate against the evolving virulence and drug resistance of current viruses. This highlights the urgent need for new and improved vaccines, diagnostics and therapeutic agents to obviate the viral pandemic. KEY FINDINGS Benzothiazole plays a pivotal role in the design and development of antiviral drugs. This is evident from the fact that it comprises many clinically useful agents. The current review is aimed to provide an insight into the recent development of benzothiazole-based antiviral agents, with a special focus on their structure-activity relationships and lead optimisation. One hundred and five articles were initially identified, and from these studies, 64 potential novel lead molecules and main findings were highlighted in this review. SUMMARY We hope this review will provide a logical perspective on the importance of improving the future designs of novel broad-spectrum benzothiazole-based antiviral agents to be used against emerging viral diseases.
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Affiliation(s)
- Yahya I Asiri
- Department of Pharmacology, College of Pharmacy, King Khalid University, Abha, Saudi Arabia
| | - Abdulrhman Alsayari
- Department of Pharmacognosy, College of Pharmacy, King Khalid University, Abha, Saudi Arabia
| | - Abdullatif B Muhsinah
- Department of Pharmacognosy, College of Pharmacy, King Khalid University, Abha, Saudi Arabia
| | - Yahia N Mabkhot
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Khalid University, Abha, Saudi Arabia
| | - Mohd Z Hassan
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Khalid University, Abha, Saudi Arabia
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Çapcı A, Lorion MM, Mai C, Hahn F, Hodek J, Wangen C, Weber J, Marschall M, Ackermann L, Tsogoeva SB. (Iso)Quinoline-Artemisinin Hybrids Prepared through Click Chemistry: Highly Potent Agents against Viruses. Chemistry 2020; 26:12019-12026. [PMID: 32485071 PMCID: PMC7540715 DOI: 10.1002/chem.202001803] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Indexed: 12/19/2022]
Abstract
Viral infections cause life-threatening diseases in millions of people worldwide every year and there is an urgent need for new, effective antiviral drugs. Hybridization of two chemically diverse compounds into a new bioactive effector product is a successful concept to improve the properties of a hybrid drug relative to the parent compounds. In this study, (iso)quinoline-artemisinin hybrids, obtained through copper-catalyzed azide-alkyne cycloaddition or metal-free click reactions (in organic solvents or in the presence of water), were analyzed in vitro, for the first time, for their inhibitory activity against human cytomegalovirus (HCMV), relative to their parent compounds and the reference drug ganciclovir. EC50 (HCMV) values were obtained in a range 0.22-1.20 μm, which indicated highly potent antiviral properties in the absence of cytotoxic effects on normal cells (CC50 >100 μm). The most active hybrid, 1 (EC50 =0.22 μm), is 25 times more potent than its parent compound artesunic acid (EC50 =5.41 μm) and 12 times more efficient than the standard drug ganciclovir (EC50 =2.6 μm). Interestingly, hybrid 1 also shows inhibitory activity against hepatitis B virus in vitro (EC50 (HBeAg)=2.57 μm).
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Affiliation(s)
- Aysun Çapcı
- Organic Chemistry Chair I and Interdisciplinary Center for, Molecular Materials (ICMM)Friedrich-Alexander University of, Erlangen–NürnbergNikolaus Fiebiger-Straße 1091058ErlangenGermany
| | - Mélanie M. Lorion
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
| | - Christina Mai
- Organic Chemistry Chair I and Interdisciplinary Center for, Molecular Materials (ICMM)Friedrich-Alexander University of, Erlangen–NürnbergNikolaus Fiebiger-Straße 1091058ErlangenGermany
| | - Friedrich Hahn
- Institute for Clinical and Molecular VirologyFriedrich-Alexander University of Erlangen-NürnbergSchlossgarten 491054ErlangenGermany
| | - Jan Hodek
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of SciencesFlemingovo namesti 216610PragueCzech Republic
| | - Christina Wangen
- Institute for Clinical and Molecular VirologyFriedrich-Alexander University of Erlangen-NürnbergSchlossgarten 491054ErlangenGermany
| | - Jan Weber
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of SciencesFlemingovo namesti 216610PragueCzech Republic
| | - Manfred Marschall
- Institute for Clinical and Molecular VirologyFriedrich-Alexander University of Erlangen-NürnbergSchlossgarten 491054ErlangenGermany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
- German Center for Cardiovascular Research (DZHK)Potsdamer Str. 5810785BerlinGermany
| | - Svetlana B. Tsogoeva
- Organic Chemistry Chair I and Interdisciplinary Center for, Molecular Materials (ICMM)Friedrich-Alexander University of, Erlangen–NürnbergNikolaus Fiebiger-Straße 1091058ErlangenGermany
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7
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Sinigaglia A, Peta E, Riccetti S, Barzon L. New avenues for therapeutic discovery against West Nile virus. Expert Opin Drug Discov 2020; 15:333-348. [DOI: 10.1080/17460441.2020.1714586] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
| | - Elektra Peta
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Silvia Riccetti
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Luisa Barzon
- Department of Molecular Medicine, University of Padova, Padova, Italy
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8
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Synthesis of pyrazolo- and [1,2,4]triazolo-[1,5-а]quinolin-9-ols by cycloaddition to 8-hydroxyquinoline N-imide. Chem Heterocycl Compd (N Y) 2019. [DOI: 10.1007/s10593-019-02446-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Martinez AA, Espinosa BA, Adamek RN, Thomas BA, Chau J, Gonzalez E, Keppetipola N, Salzameda NT. Breathing new life into West Nile virus therapeutics; discovery and study of zafirlukast as an NS2B-NS3 protease inhibitor. Eur J Med Chem 2018; 157:1202-1213. [PMID: 30193218 DOI: 10.1016/j.ejmech.2018.08.077] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/06/2018] [Accepted: 08/27/2018] [Indexed: 10/28/2022]
Abstract
The West Nile virus (WNV) has spread throughout the world causing neuroinvasive diseases with no treatments available. The viral NS2B-NS3 protease is essential for WNV survival and replication in host cells and is a promising drug target. Through an enzymatic screen of the National Institute of Health clinical compound library, we report the discovery of zafirlukast, an FDA approved treatment for asthma, as an inhibitor for the WNV NS2B-NS3 protease. Zafirlukast was determined to inhibit the protease through a mixed mode mechanism with an IC50 value of 32 μM. A structure activity relationship study of zafirlukast revealed the cyclopentyl carbamate and N-aryl sulfonamide as structural elements crucial for NS2B-NS3 protease inhibition. Replacing the cyclopentyl with a phenyl improved inhibition, resulting in an IC50 of 22 μM. Experimental and computational docking analysis support the inhibition model of zafirlukast and analogs binding at an allosteric site on the NS3 protein, thereby disrupting the NS2B cofactor from binding, resulting in protease inhibition.
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Affiliation(s)
- Anastasia A Martinez
- Department of Chemistry & Biochemistry, California State University, Fullerton, 800 N. State College, Fullerton, CA, 92831, USA
| | - Bianca A Espinosa
- Department of Chemistry & Biochemistry, California State University, Fullerton, 800 N. State College, Fullerton, CA, 92831, USA
| | - Rebecca N Adamek
- Department of Chemistry & Biochemistry, California State University, Fullerton, 800 N. State College, Fullerton, CA, 92831, USA
| | - Brent A Thomas
- Department of Chemistry & Biochemistry, California State University, Fullerton, 800 N. State College, Fullerton, CA, 92831, USA
| | - Jennifer Chau
- Department of Chemistry & Biochemistry, California State University, Fullerton, 800 N. State College, Fullerton, CA, 92831, USA
| | - Edwardo Gonzalez
- Department of Chemistry & Biochemistry, California State University, Fullerton, 800 N. State College, Fullerton, CA, 92831, USA
| | - Niroshika Keppetipola
- Department of Chemistry & Biochemistry, California State University, Fullerton, 800 N. State College, Fullerton, CA, 92831, USA
| | - Nicholas T Salzameda
- Department of Chemistry & Biochemistry, California State University, Fullerton, 800 N. State College, Fullerton, CA, 92831, USA.
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Strategies Towards Protease Inhibitors for Emerging Flaviviruses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1062:175-186. [PMID: 29845533 PMCID: PMC7121277 DOI: 10.1007/978-981-10-8727-1_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Infections with flaviviruses are a continuing public health threat. In addition to vaccine development and vector control, the search for antiviral agents that alleviate symptoms in patients are of considerable interest. Among others, the flaviviral protease NS2B-NS3 is a promising drug target to inhibit viral replication. Flaviviral proteases share a high degree of structural similarity and substrate-recognition profile, which may facilitate a strategy towards development of pan-flaviviral protease inhibitors. However, the success of various drug discovery attempts during the last decade has been limited by the nature of the viral enzyme as well as a lack of robust structural templates. Small-molecular, structurally diverse protease inhibitors have been reported to reach affinities in the lower micromolar range. Peptide-based, substrate-derived compounds are often nanomolar inhibitors, however, with highly compromised drug-likeness. With some exceptions, the antiviral cellular activity of most of the reported compounds have been patchy and insufficient for further development. Recent progress has been made in the elucidation of inhibitor binding using different structural methods. This will hopefully lead to more rational attempts for the identification of various lead compounds that may be successful in cellular assays, animal models and ultimately translated to patients.
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de la Guardia C, Stephens DE, Dang HT, Quijada M, Larionov OV, Lleonart R. Antiviral Activity of Novel Quinoline Derivatives against Dengue Virus Serotype 2. Molecules 2018; 23:molecules23030672. [PMID: 29547522 PMCID: PMC5997395 DOI: 10.3390/molecules23030672] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 03/13/2018] [Accepted: 03/15/2018] [Indexed: 12/14/2022] Open
Abstract
Dengue virus causes dengue fever, a debilitating disease with an increasing incidence in many tropical and subtropical territories. So far, there are no effective antivirals licensed to treat this virus. Here we describe the synthesis and antiviral activity evaluation of two compounds based on the quinoline scaffold, which has shown potential for the development of molecules with various biological activities. Two of the tested compounds showed dose-dependent inhibition of dengue virus serotype 2 in the low and sub micromolar range. The compounds 1 and 2 were also able to impair the accumulation of the viral envelope glycoprotein in infected cells, while showing no sign of direct virucidal activity and acting possibly through a mechanism involving the early stages of the infection. The results are congruent with previously reported data showing the potential of quinoline derivatives as a promising scaffold for the development of new antivirals against this important virus.
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Affiliation(s)
- Carolina de la Guardia
- Institute of Scientific Research and High Technology Services (INDICASAT AIP), PO 0843-01103 City of Panama, Panama.
- Department of Biotechnology, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur 522510, Andhra Pradesh, India.
| | - David E Stephens
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, USA.
| | - Hang T Dang
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, USA.
| | - Mario Quijada
- Institute of Scientific Research and High Technology Services (INDICASAT AIP), PO 0843-01103 City of Panama, Panama.
| | - Oleg V Larionov
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, USA.
| | - Ricardo Lleonart
- Institute of Scientific Research and High Technology Services (INDICASAT AIP), PO 0843-01103 City of Panama, Panama.
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12
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STD-NMR experiments identify a structural motif with novel second-site activity against West Nile virus NS2B-NS3 protease. Antiviral Res 2017; 146:174-183. [PMID: 28927677 DOI: 10.1016/j.antiviral.2017.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/09/2017] [Accepted: 09/14/2017] [Indexed: 11/22/2022]
Abstract
West Nile virus (WNV) belongs to the genus Flavivirus of the family Flaviviridae. This mosquito-borne virus that is highly pathogenic to humans has been evolving into a global threat during the past two decades. Despite many efforts, neither antiviral drugs nor vaccines are available. The viral protease NS2B-NS3pro is essential for viral replication, and therefore it is considered a prime drug target. However, success in the development of specific NS2B-NS3pro inhibitors had been moderate so far. In the search for new structural motifs with binding affinity for NS2B-NS3pro, we have screened a fragment library, the Maybridge Ro5 library, employing saturation transfer difference (STD) NMR experiments as readout. About 30% of 429 fragments showed binding to NS2B-NS3pro. Subsequent STD-NMR competition experiments using the known active site fragment A as reporter ligand yielded 14 competitively binding fragments, and 22 fragments not competing with A. In a fluorophore-based protease assay, all of these fragments showed inhibition in the micromolar range. Interestingly, 10 of these 22 fragments showed a notable increase of STD intensities in the presence of compound A suggesting cooperative binding. The most promising non-competitive inhibitors 1 and 2 (IC50 ∼ 500 μM) share a structural motif that may guide the development of novel second-site (potentially allosteric) inhibitors of NS2B-NS3pro. To identify the matching protein binding site, chemical shift perturbation studies employing 1H,15N-TROSY-HSQC experiments with uniformly 2H,15N-labeled protease were performed in the presence of 1, and in the concomitant absence or presence of A. The data suggest that 1 interacts with Met 52* of NS2B, identifying a secondary site adjacent to the binding site of A. Therefore, our study paves the way for the synthesis of novel bidentate NS2B-NS3pro inhibitors.
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13
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Balasubramanian A, Manzano M, Teramoto T, Pilankatta R, Padmanabhan R. High-throughput screening for the identification of small-molecule inhibitors of the flaviviral protease. Antiviral Res 2016; 134:6-16. [PMID: 27539384 DOI: 10.1016/j.antiviral.2016.08.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/13/2016] [Indexed: 01/18/2023]
Abstract
The mosquito-borne dengue virus serotypes 1-4 (DENV1-4) and West Nile virus (WNV) cause serious illnesses worldwide associated with considerable morbidity and mortality. According to the World Health Organization (WHO) estimates, there are about 390 million infections every year leading to ∼500,000 dengue haemorrhagic fever (DHF) cases and ∼25,000 deaths, mostly among children. Antiviral therapies could reduce the morbidity and mortality associated with flaviviral infections, but currently there are no drugs available for treatment. In this study, a high-throughput screening assay for the Dengue protease was employed to screen ∼120,000 small molecule compounds for identification of inhibitors. Eight of these inhibitors have been extensively analyzed for inhibition of the viral protease in vitro and cell-based viral replication using Renilla luciferase reporter replicon, infectivity (plaque) and cytotoxicity assays. Three of these compounds were identified as potent inhibitors of DENV and WNV proteases, and viral replication of DENV2 replicon and infectious RNA. Fluorescence quenching, kinetic analysis and molecular modeling of these inhibitors into the structure of NS2B-NS3 protease suggest a mode of inhibition for three compounds that they bind to the substrate binding pocket.
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Affiliation(s)
| | - Mark Manzano
- Department of Microbiology and Immunology, Georgetown University, Washington, D.C., USA
| | - Tadahisa Teramoto
- Department of Microbiology and Immunology, Georgetown University, Washington, D.C., USA
| | - Rajendra Pilankatta
- Department of Microbiology and Immunology, Georgetown University, Washington, D.C., USA
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Discovery of antiviral molecules for dengue: In silico search and biological evaluation. Eur J Med Chem 2016; 110:87-97. [PMID: 26807547 DOI: 10.1016/j.ejmech.2015.12.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 11/08/2015] [Accepted: 12/14/2015] [Indexed: 12/24/2022]
Abstract
BACKGROUND Dengue disease is a global disease that has no effective treatment. The dengue virus (DENV) NS2B/NS3 protease complex is a target for designing specific antivirals due to its importance in viral replication and its high degree of conservation. METHODS NS2B/NS3 protease complex structural information was employed to find small molecules that are capable of inhibiting the activity of the enzyme complex. This inhibitory activity was probed with in vitro assays using a fluorescent substrate and the complex NS2B/NS3 obtained by recombinant DNA techniques. HepG2 cells infected with dengue virus serotype 2 were used to test the activity against dengue virus replication. RESULTS A total of 210,903 small molecules from PubChem were docked in silico to the NS2B/NS3 structure (PDB: 2FOM) to find molecules that were capable of inhibiting this protein complex. Five of the best 500 leading compounds, according to their affinity values (-11.6 and -13.5 kcal/mol), were purchased. The inhibitory protease activity on the recombinant protein and antiviral assays was tested. CONCLUSIONS Chemicals CID 54681617, CID 54692801 and CID 54715399 were strong inhibitors of NS2B/NS3, with IC50 values (μM) and percentages of viral titer reductions of 19.9, 79.9%; 17.5, 69.8%; and 9.1, 73.9%, respectively. Multivariate methods applied to the molecular descriptors showed two compounds that were structurally different from other DENV inhibitors. GENERAL SIGNIFICANCE This discovery opens new possibilities for obtaining drug candidates against Dengue virus.
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15
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Bastos Lima A, Behnam MA, El Sherif Y, Nitsche C, Vechi SM, Klein CD. Dual inhibitors of the dengue and West Nile virus NS2B–NS3 proteases: Synthesis, biological evaluation and docking studies of novel peptide-hybrids. Bioorg Med Chem 2015; 23:5748-55. [DOI: 10.1016/j.bmc.2015.07.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 07/08/2015] [Accepted: 07/09/2015] [Indexed: 10/23/2022]
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16
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Effects of 2-amino-8-hydroxyquinoline interaction on the conformation of physiological isomers of human serum albumin. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2015; 44:193-205. [PMID: 25761396 DOI: 10.1007/s00249-015-1014-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 02/14/2015] [Accepted: 02/20/2015] [Indexed: 10/23/2022]
Abstract
The methods of synthetic chemistry create small molecules rapidly for screening, and ligand-protein interaction studies provide information on how a potential drug interacts with target or carrier proteins such as serum albumin. In this work, we investigate the interaction of amino derivative of 8-hydroxyquinoline, 2-amino-8-hydroxyquinoline (A8HQ), and the effects of its binding on the conformation of different isomers of human serum albumin (HSA) using multispectroscopic techniques and molecular modeling. We found that B isomer, which exists at pH 9, bound A8HQ (K a = 1.92 ± 0.07 × 10(5) M(-1) at 298 K) more strongly as compared with N isomer (K a = 1.19 ± 0.04 × 10(5) M(-1) at 298 K) of HSA, which is known to exist around pH 6. The binding constant at physiological pH (7.4) was also determined, and the value (K a = 1.38 ± 0.05 × 10(5) M(-1) at 298 K) was found to fall between those for N and B isomers, suggesting that both the N and B isomers exist in an equilibrium in plasma. We also determined the thermodynamic parameters such as changes in enthalpy, entropy , and free energy of binding by measuring the binding at four different temperatures. Based on molecular modeling and thermodynamic studies, we propound that the A8HQ-HSA binding involves mainly hydrophobic interactions and hydrogen bonding. Site-specific marker displacement experiments and molecular modeling showed that the molecule preferably binds in subdomain IIA close to Trp214. A8HQ binding to HSA isomers was found to cause both secondary and tertiary structural alterations in the protein.
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Elseginy SA, Massarotti A, Nawwar GAM, Amin KM, Brancale A. Small Molecule Inhibitors of West Nile Virus. ACTA ACUST UNITED AC 2014; 23:179-87. [DOI: 10.3851/imp2581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2013] [Indexed: 10/26/2022]
Abstract
West Nile virus (WNV) is a human pathogen which is rapidly expanding worldwide. It is a member of the Flavivirus genus and it is transmitted by mosquitos between its avian hosts and occasionally in mammalian hosts. In humans the infection is often asymptomatic, however, the most severe cases result in encephalitis or meningitis. Approximately 10% of cases of neuroinvasive disease are fatal. To date there is no effective human vaccine or effective antiviral therapy available to treat WNV infections. For this reason, research in this field is rapidly growing. In this article we will review the latest efforts in the design and development of novel WNV inhibitors from a medicinal chemistry point of view, highlighting challenges and opportunities for the researchers working in this field.
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Affiliation(s)
- Samia A Elseginy
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| | - Alberto Massarotti
- Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale ‘A Avogadro’, Novara, Italy
| | - Galal AM Nawwar
- Department of Chemical Industries, National Research Centre, Giza, Egypt
| | - Kamilia M Amin
- Department of Therapeutic Chemistry, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
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18
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Nitsche C, Holloway S, Schirmeister T, Klein CD. Biochemistry and medicinal chemistry of the dengue virus protease. Chem Rev 2014; 114:11348-81. [PMID: 25268322 DOI: 10.1021/cr500233q] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Christoph Nitsche
- Medicinal Chemistry, Institute of Pharmacy and Molecular Biotechnology IPMB, Heidelberg University , Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany
| | - Steven Holloway
- Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz , Staudingerweg 5, D-55128 Mainz, Germany
| | - Tanja Schirmeister
- Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz , Staudingerweg 5, D-55128 Mainz, Germany
| | - Christian D Klein
- Medicinal Chemistry, Institute of Pharmacy and Molecular Biotechnology IPMB, Heidelberg University , Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany
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19
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Amodiaquine, an antimalarial drug, inhibits dengue virus type 2 replication and infectivity. Antiviral Res 2014; 106:125-34. [PMID: 24680954 PMCID: PMC4523242 DOI: 10.1016/j.antiviral.2014.03.014] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 03/14/2014] [Accepted: 03/18/2014] [Indexed: 12/14/2022]
Abstract
Dengue virus serotypes 1-4 (DENV1-4) are transmitted by mosquitoes which cause most frequent arboviral infections in the world resulting in ∼390 million cases with ∼25,000 deaths annually. There is no vaccine or antiviral drug currently available for human use. Compounds containing quinoline scaffold were shown to inhibit flavivirus NS2B-NS3 protease (NS2B-NS3pro) with good potencies. In this study, we screened quinoline derivatives, which are known antimalarial drugs for inhibition of DENV2 and West Nile virus (WNV) replication using the corresponding replicon expressing cell-based assays. Amodiaquine (AQ), one of the 4-aminoquinoline drugs, inhibited DENV2 infectivity measured by plaque assays, with EC50 and EC90 values of 1.08±0.09μM and 2.69±0.47 μM, respectively, and DENV2 RNA replication measured by Renilla luciferase reporter assay, with EC50 value of 7.41±1.09μM in the replicon expressing cells. Cytotoxic concentration (CC50) in BHK-21 cells was 52.09±4.25μM. The replication inhibition was confirmed by plaque assay of the extracellular virions as well as by qRT-PCR of the intracellular and extracellular viral RNA levels. AQ was stable for at least 96h and had minor inhibitory effect on entry, translation, and post-replication stages in the viral life cycle. DENV protease, 5'-methyltransferase, and RNA-dependent RNA polymerase do not seem to be targets of AQ. Both p-hydroxyanilino and diethylaminomethyl moieties are important for AQ to inhibit DENV2 replication and infectivity. Our results support AQ as a promising candidate for anti-flaviviral therapy.
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20
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Recent Advances in Targeting Dengue and West Nile Virus Proteases Using Small Molecule Inhibitors. TOPICS IN MEDICINAL CHEMISTRY 2014. [DOI: 10.1007/7355_2014_46] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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21
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Lim SP, Shi PY. West Nile virus drug discovery. Viruses 2013; 5:2977-3006. [PMID: 24300672 PMCID: PMC3967157 DOI: 10.3390/v5122977] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 11/25/2013] [Accepted: 11/25/2013] [Indexed: 02/08/2023] Open
Abstract
The outbreak of West Nile virus (WNV) in 1999 in the USA, and its continued spread throughout the Americas, parts of Europe, the Middle East and Africa, underscored the need for WNV antiviral development. Here, we review the current status of WNV drug discovery. A number of approaches have been used to search for inhibitors of WNV, including viral infection-based screening, enzyme-based screening, structure-based virtual screening, structure-based rationale design, and antibody-based therapy. These efforts have yielded inhibitors of viral or cellular factors that are critical for viral replication. For small molecule inhibitors, no promising preclinical candidate has been developed; most of the inhibitors could not even be advanced to the stage of hit-to-lead optimization due to their poor drug-like properties. However, several inhibitors developed for related members of the family Flaviviridae, such as dengue virus and hepatitis C virus, exhibited cross-inhibition of WNV, suggesting the possibility to re-purpose these antivirals for WNV treatment. Most promisingly, therapeutic antibodies have shown excellent efficacy in mouse model; one of such antibodies has been advanced into clinical trial. The knowledge accumulated during the past fifteen years has provided better rationale for the ongoing WNV and other flavivirus antiviral development.
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Affiliation(s)
- Siew Pheng Lim
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, Chromos 05-01, Singapore 138670, Singapore.
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22
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The flavivirus protease as a target for drug discovery. Virol Sin 2013; 28:326-36. [PMID: 24242363 DOI: 10.1007/s12250-013-3390-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/01/2013] [Indexed: 01/27/2023] Open
Abstract
Many flaviviruses are significant human pathogens causing considerable disease burdens, including encephalitis and hemorrhagic fever, in the regions in which they are endemic. A paucity of treatments for flaviviral infections has driven interest in drug development targeting proteins essential to flavivirus replication, such as the viral protease. During viral replication, the flavivirus genome is translated as a single polyprotein precursor, which must be cleaved into individual proteins by a complex of the viral protease, NS3, and its cofactor, NS2B. Because this cleavage is an obligate step of the viral life-cycle, the flavivirus protease is an attractive target for antiviral drug development. In this review, we will survey recent drug development studies targeting the NS3 active site, as well as studies targeting an NS2B/NS3 interaction site determined from flavivirus protease crystal structures.
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23
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Adamek RN, Maniquis RV, Khakoo S, Bridges MD, Salzameda NT. A FRET-based assay for the discovery of West Nile Virus NS2B-NS3 protease inhibitors. Bioorg Med Chem Lett 2013; 23:4848-50. [DOI: 10.1016/j.bmcl.2013.06.081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 06/17/2013] [Accepted: 06/27/2013] [Indexed: 10/26/2022]
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24
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Prusis P, Junaid M, Petrovska R, Yahorava S, Yahorau A, Katzenmeier G, Lapins M, Wikberg JES. Design and evaluation of substrate-based octapeptide and non substrate-based tetrapeptide inhibitors of dengue virus NS2B-NS3 proteases. Biochem Biophys Res Commun 2013; 434:767-72. [PMID: 23587903 DOI: 10.1016/j.bbrc.2013.03.139] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 03/29/2013] [Indexed: 12/13/2022]
Abstract
A series of 45 peptide inhibitors was designed, synthesized, and evaluated against the NS2B-NS3 proteases of the four subtypes of dengue virus, DEN-1-4. The design was based on proteochemometric models for Michaelis (Km) and cleavage rate constants (kcat) of protease substrates. This led first to octapeptides showing submicromolar or low micromolar inhibitory activities on the four proteases. Stepwise removal of cationic substrate non-prime side residues and variations in the prime side sequence resulted finally in an uncharged tetrapeptide, WYCW-NH2, with inhibitory Ki values of 4.2, 4.8, 24.4, and 11.2 μM for the DEN-1-4 proteases, respectively. Analysis of the inhibition data by proteochemometric modeling suggested the possibility for different binding poses of the shortened peptides compared to the octapeptides, which was supported by results of docking of WYCW-NH2 into the X-ray structure of DEN-3 protease.
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Affiliation(s)
- Peteris Prusis
- Department of Pharmaceutical Biosciences, Division of Pharmacology, Uppsala University, 75124 Uppsala, Sweden
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25
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Kim YM, Gayen S, Kang C, Joy J, Huang Q, Chen AS, Wee JLK, Ang MJY, Lim HA, Hung AW, Li R, Noble CG, Lee LT, Yip A, Wang QY, Chia CSB, Hill J, Shi PY, Keller TH. NMR analysis of a novel enzymatically active unlinked dengue NS2B-NS3 protease complex. J Biol Chem 2013; 288:12891-900. [PMID: 23511634 DOI: 10.1074/jbc.m112.442723] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The dengue virus (DENV) is a mosquito-borne pathogen responsible for an estimated 100 million human infections annually. The viral genome encodes a two-component trypsin-like protease that contains the cofactor region from the nonstructural protein NS2B and the protease domain from NS3 (NS3pro). The NS2B-NS3pro complex plays a crucial role in viral maturation and has been identified as a potential drug target. Using a DENV protease construct containing NS2B covalently linked to NS3pro via a Gly4-Ser-Gly4 linker ("linked protease"), previous x-ray crystal structures show that the C-terminal fragment of NS2B is remote from NS3pro and exists in an open state in the absence of an inhibitor; however, in the presence of an inhibitor, NS2B complexes with NS3pro to form a closed state. This linked enzyme produced NMR spectra with severe signal overlap and line broadening. To obtain a protease construct with a resolved NMR spectrum, we expressed and purified an unlinked protease complex containing a 50-residue segment of the NS2B cofactor region and NS3pro without the glycine linker using a coexpression system. This unlinked protease complex was catalytically active at neutral pH in the absence of glycerol and produced dispersed cross-peaks in a (1)H-(15)N heteronuclear single quantum correlation spectrum that enabled us to conduct backbone assignments using conventional techniques. In addition, titration with an active-site peptide aldehyde inhibitor and paramagnetic relaxation enhancement studies demonstrated that the unlinked DENV protease exists predominantly in a closed conformation in solution. This protease complex can serve as a useful tool for drug discovery against DENV.
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Affiliation(s)
- Young Mee Kim
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore 138669
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26
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Hammamy MZ, Haase C, Hammami M, Hilgenfeld R, Steinmetzer T. Development and characterization of new peptidomimetic inhibitors of the West Nile virus NS2B-NS3 protease. ChemMedChem 2013; 8:231-41. [PMID: 23307694 DOI: 10.1002/cmdc.201200497] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 12/07/2012] [Indexed: 11/08/2022]
Abstract
A series of new substrate analogue inhibitors of the WNV NS2B-NS3 protease containing decarboxylated arginine mimetics at the P1 position was developed. Among the various analogues, trans-(4-guanidino)cyclohexylmethylamide (GCMA) was identified as the most suitable P1 residue. In combination with dichloro-substituted phenylacetyl groups at the P4 position, three inhibitors with inhibition constants of <0.2 μM were obtained. These GCMA inhibitors have a better selectivity profile than the previously described agmatine analogues, and possess negligible affinity for the trypsin-like serine proteases thrombin, factor Xa, and matriptase. A crystal structure in complex with the WNV protease was determined for one of the most potent inhibitors, 3,4-dichlorophenylacetyl-Lys-Lys-GCMA (K(i)=0.13 μM). The inhibitor adopts a horseshoe-like conformation, most likely due to a hydrophobic contact between the P4 phenyl ring and the P1 cyclohexyl group, which is further stabilized by an intramolecular hydrogen bond between the P1 guanidino group and the P4 carbonyl oxygen atom. These inhibitors are stable, readily accessible, and have a noncovalent binding mode. Therefore, they may serve as suitable lead structures for further development.
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Affiliation(s)
- M Zouhir Hammamy
- Institute of Pharmaceutical Chemistry, Philipps University, Marbacher Weg 6, 35032 Marburg, Germany
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27
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Lai H, Dou D, Aravapalli S, Teramoto T, Lushington GH, Mwania TM, Alliston KR, Eichhorn DM, Padmanabhan R, Groutas WC. Design, synthesis and characterization of novel 1,2-benzisothiazol-3(2H)-one and 1,3,4-oxadiazole hybrid derivatives: potent inhibitors of Dengue and West Nile virus NS2B/NS3 proteases. Bioorg Med Chem 2013; 21:102-13. [PMID: 23211969 PMCID: PMC3563426 DOI: 10.1016/j.bmc.2012.10.058] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 10/22/2012] [Accepted: 10/31/2012] [Indexed: 12/27/2022]
Abstract
1,2-Benzisothiazol-3(2H)-ones and 1,3,4-oxadiazoles individually have recently attracted considerable interest in drug discovery, including as antibacterial and antifungal agents. In this study, a series of functionalized 1,2-benzisothiazol-3(2H)-one-1,3,4-oxadiazole hybrid derivatives were synthesized and subsequently screened against Dengue and West Nile virus proteases. Ten out of twenty-four compounds showed greater than 50% inhibition against DENV2 and WNV proteases ([I] = 10 μM). The IC(50) values of compound 7n against DENV2 and WNV NS2B/NS3 were found to be 3.75 ± 0.06 and 4.22 ± 0.07 μM, respectively. The kinetics data support a competitive mode of inhibition by compound 7n. Molecular modeling studies were performed to delineate the putative binding mode of this series of compounds. This study reveals that the hybrid series arising from the linking of the two scaffolds provides a suitable platform for conducting a hit-to-lead optimization campaign via iterative structure-activity relationship studies, in vitro screening and X-ray crystallography.
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Affiliation(s)
- Huiguo Lai
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Dengfeng Dou
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
| | - Sridhar Aravapalli
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
| | - Tadahisa Teramoto
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Gerald H. Lushington
- Molecular Graphics and Modeling Laboratory, The University of Kansas, Lawrence, KS 66045, USA
| | - Tom M. Mwania
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
| | - Kevin R. Alliston
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
| | - David M. Eichhorn
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
| | - R. Padmanabhan
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - William C. Groutas
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
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Kang C, Gayen S, Wang W, Severin R, Chen AS, Lim HA, Chia CSB, Schüller A, Doan DNP, Poulsen A, Hill J, Vasudevan SG, Keller TH. Exploring the binding of peptidic West Nile virus NS2B-NS3 protease inhibitors by NMR. Antiviral Res 2012; 97:137-44. [PMID: 23211132 DOI: 10.1016/j.antiviral.2012.11.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/23/2012] [Accepted: 11/24/2012] [Indexed: 11/26/2022]
Abstract
West Nile virus (WNV) NS2B-NS3 protease is an important drug target since it is an essential protein for the replication of the virus. In order to determine the minimum pharmacophore for protease inhibition, a series of dipeptide aldehydes were synthesized. The 50% inhibitory concentration (IC(50)) measurements revealed that a simple acetyl-KR-aldehyde was only threefold less active than 4-phenyl-phenylacetyl-KKR-aldehyde (1) (Stoermer et al., 2008) that was used as the reference compound. The ligand efficiency of 0.40 kcal/mol/HA (HA=heavy atom) for acetyl-KR-aldehyde is much improved compared to the reference compound 1 (0.23 kcal/mol/HA). The binding of the inhibitors was examined using (1)H-(15)N-HSQC experiments and differential chemical shifts were used to map the ligand binding sites. The biophysical studies show that the conformational mobility of WNV protease has a major impact on the design of novel inhibitors, since the protein conformation changes profoundly depending on the structure of the bound ligand.
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Affiliation(s)
- CongBao Kang
- Experimental Therapeutics Center, Nanos, Singapore, Singapore
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Lai H, Sridhar Prasad G, Padmanabhan R. Characterization of 8-hydroxyquinoline derivatives containing aminobenzothiazole as inhibitors of dengue virus type 2 protease in vitro. Antiviral Res 2012; 97:74-80. [PMID: 23127365 DOI: 10.1016/j.antiviral.2012.10.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 10/21/2012] [Accepted: 10/26/2012] [Indexed: 11/17/2022]
Abstract
Four serotypes of dengue virus (DENV1-4), mosquito-borne members of Flaviviridae family cause frequent epidemics causing considerable morbidity and mortality in humans throughout tropical regions of the world. There is no vaccine or antiviral therapeutics available for human use. In a previous study, we reported that compounds containing the 8-hydroxyquinoline (8-HQ) scaffold as inhibitors of West Nile virus serine protease. In this study, we analyzed potencies of some compounds with (8-HQ)-aminobenzothiazole derivatives for inhibition of DENV2 protease in vitro. We identified analogs 1-4 with 2-aminothiazole or 2-aminobenzothiazole scaffold with sub-micromolar potencies (IC(50)) in the in vitro protease assays. The kinetic constant (K(i)) for the most potent 8-HQ-aminobenzothiazole inhibitor (compound 1) with an IC(50) value of 0.91±0.05μM was determined to be 2.36±0.13μM. This compound inhibits the DENV2 NS2B/NS3pro by a competitive mode of inhibition.
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Affiliation(s)
- Huiguo Lai
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057, USA
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Aravapalli S, Lai H, Teramoto T, Alliston KR, Lushington GH, Ferguson EL, Padmanabhan R, Groutas WC. Inhibitors of Dengue virus and West Nile virus proteases based on the aminobenzamide scaffold. Bioorg Med Chem 2012; 20:4140-8. [PMID: 22632792 PMCID: PMC3563422 DOI: 10.1016/j.bmc.2012.04.055] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 04/19/2012] [Accepted: 04/27/2012] [Indexed: 10/28/2022]
Abstract
Dengue and West Nile viruses (WNV) are mosquito-borne members of flaviviruses that cause significant morbidity and mortality. There is no approved vaccine or antiviral drugs for human use to date. In this study, a series of functionalized meta and para aminobenzamide derivatives were synthesized and subsequently screened in vitro against Dengue virus and West Nile virus proteases. Four active compounds were identified which showed comparable activity toward the two proteases and shared in common a meta or para(phenoxy)phenyl group. The inhibition constants (K(i)) for the most potent compound 7n against Dengue and West Nile virus proteases were 8.77 and 5.55 μM, respectively. The kinetics data support a competitive mode of inhibition of both proteases by compound 7n. This conclusion is further supported by molecular modeling. This study reveals a new chemical scaffold which is amenable to further optimization to yield potent inhibitors of the viral proteases via the combined utilization of iterative medicinal chemistry/structure-activity relationship studies and in vitro screening.
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Affiliation(s)
- Sridhar Aravapalli
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
| | - Huiguo Lai
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Tadahisa Teramoto
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Kevin R. Alliston
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
| | - Gerald H. Lushington
- Molecular Graphics and Modeling Laboratory, The University of Kansas, Lawrence, KS 66045, USA
| | - Eron L. Ferguson
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
| | - R. Padmanabhan
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - William C. Groutas
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260, USA
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