| 1. |
- Akaberi, Dario, et al.
(författare)
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Identification of a C2-symmetric diol based human immunodeficiency virus protease inhibitor targeting Zika virus NS2B-NS3 protease
- 2020
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Ingår i: Journal of Biomolecular Structure and Dynamics. - : Informa UK Limited. - 0739-1102 .- 1538-0254. ; 38:18, s. 5526-5536
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Tidskriftsartikel (refereegranskat)abstract
- Zika virus (ZIKV) is an emerging mosquito-borne flavivirus and infection by ZIKV Asian lineage is known to cause fetal brain anomalies and Guillain-Barrés syndrome. The WHO declared ZIKV a global public health emergency in 2016. However, currently neither vaccines nor antiviral prophylaxis/treatments are available. In this study, we report the identification of a C2-symmetric diol-based Human immunodeficiency virus type-1 (HIV) protease inhibitor active against ZIKV NS2B-NS3 protease. The compound, referred to as 9b, was identified by in silico screening of a library of 6265 protease inhibitors. Molecular dynamics (MD) simulation studies revealed that compound 9b formed a stable complex with ZIKV protease. Interaction analysis of compound 9b's binding pose from the cluster analysis of MD simulations trajectories predicted that 9b mostly interacted with ZIKV NS3. Although designed as an aspartyl protease inhibitor, compound 9b was found to inhibit ZIKV serine protease in vitro with IC50 = 143.25 ± 5.45 µM, in line with the in silico results. Additionally, linear interaction energy method (LIE) was used to estimate binding affinities of compounds 9b and 86 (a known panflavivirus peptide hybrid with IC50 = 1.64 ± 0.015 µM against ZIKV protease). The LIE method correctly predicted the binding affinity of compound 86 to be lower than that of 9b, proving to be superior to the molecular docking methods in scoring and ranking compounds. Since most of the reported ZIKV protease inhibitors are positively charged peptide-hybrids, with our without electrophilic warheads, compound 9b represents a less polar and more drug-like non-peptide hit compound useful for further optimization.Communicated by Ramaswamy Sarma.
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| 2. |
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| 3. |
- Akaberi, Dario, et al.
(författare)
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Targeting the NS2B-NS3 protease of tick-borne encephalitis virus with pan-flaviviral protease inhibitors
- 2021
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Ingår i: Antiviral Research. - : Elsevier. - 0166-3542 .- 1872-9096. ; 190
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Tidskriftsartikel (refereegranskat)abstract
- Tick-borne encephalitis (TBE) is a severe neurological disorder caused by tick-borne encephalitis virus (TBEV), a member of the Flavivirus genus. Currently, two vaccines are available in Europe against TBEV. However, TBE cases have been rising in Sweden for the past twenty years, and thousands of cases are reported in Europe, emphasizing the need for antiviral treatments against this virus. The NS2B-NS3 protease is essential for flaviviral life cycle and has been studied as a target for the design of inhibitors against several well-known flaviviruses, but not TBEV. In the present study, Compound 86, a known tripeptidic inhibitor of dengue (DENV), West Nile (WNV) and Zika (ZIKV) proteases, was predicted to be active against TBEV protease using a combination of in silico techniques. Further, Compound 86 was found to inhibit recombinant TBEV protease with an IC50 = 0.92 mu M in the in vitro enzymatic assay. Additionally, two more peptidic analogues were synthetized and they displayed inhibitory activities against both TBEV and ZIKV proteases. In particular, Compound 104 inhibited ZIKV protease with an IC50 = 0.25 mu M. These compounds represent the first reported inhibitors of TBEV protease to date and provides valuable information for the further development of TBEV as well as pan-flavivirus protease inhibitors.
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| 4. |
- Alogheli, Hiba
(författare)
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Computational Studies of Macrocycles and Molecular Modeling of Hepatitis C Virus NS3 Protease Inhibitors
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Computational tools are utilized in the drug discovery process to discover, design, and optimize new therapeutics. One important approach is structure-based drug design which relies on knowledge about the 3D structure of the biological target. The first part of this work focuses on applying structure-based drug design for binding mode prediction of HCV NS3 protease inhibitors. The NS3 protease is a challenging target from a computational perspective as it contains an extended binding site. Binding mode predictions were performed for various classes of new acyclic and macrocyclic HCV NS3 protease inhibitors and was used in the design of new inhibitors. None of the synthetized inhibitors have been co-crystallized yet, which has made the evaluation of the suggested binding mode predictions challenging.Macrocycles are an interesting compound class in drug discovery due to their unique structural architecture, which can enable access to new chemical space. Macrocycles can successfully modulate difficult therapeutic targets, as exemplified in the development of protease inhibitors. Furthermore they can improve drug-like properties, such as cell permeability and bioavailability. The second part of this thesis focuses on macrocycles from a computational point of view. A data set of 47 clinically relevant macrocycles was compiled and used in these studies. First, two different docking protocols rigid docking of pre-generated conformers and flexible docking in Glide were evaluated and compared. The results showed that flexible docking in Glide was sufficient for docking of macrocycles with respect to accuracy and speed.The aim of the second study was to evaluate and compare the performance of the more general conformational analysis tools, MCMM and MTLMOD, with the recently developed macrocycle-specialized conformational sampling tools, Prime-MCS and MMBS. In most cases, the general conformational analysis tools (with enhanced parameter settings) performed equally well as compared to the macrocycle-specialized conformational sampling techniques. However, MMBS was superior at locating the global energy minimum conformation.Finally, calculation of the conformational energy penalty of protein-bound macrocycles was performed. The macrocycle data set was complemented with linear analogues that are similar either with respect to physicochemical properties or 2D fingerprints. The conformational energy penalties of these linear analogues were calculated and compared to the conformational energy penalties of the macrocycles. The complete data set of macrocycles and non-macrocycles in this study differ from previously published work addressing conformational energy penalties, since it covers a more extended area of chemical space. Furthermore, there was a weak correlation between the calculated conformational energy penalties and the flexibility of the structures.
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| 5. |
- Barlow, Nicholas, et al.
(författare)
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Macrocyclic Peptidomimetics as Inhibitors of Insulin-Regulated Aminopeptidase (IRAP)
- 2020
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Ingår i: RSC Medicinal chemistry. - : Royal Society of Chemistry (RSC). - 2632-8682. ; 11:2, s. 234-244
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Tidskriftsartikel (refereegranskat)abstract
- Macrocyclic analogues of the linear hexapeptide, angiotensin IV (AngIV) have proved to be potent inhibitors of insulin-regulated aminopeptidase (IRAP, oxytocinase, EC 3.4.11.3). Along with higher affinity, macrocycles may also offer better metabolic stability, membrane permeability and selectivity, however predicting the outcome of particular cycle modifications is challenging. Here we describe the development of a series of macrocyclic IRAP inhibitors with either disulphide, olefin metathesis or lactam bridges and variations of ring size and other functionality. The binding mode of these compounds is proposed based on molecular dynamics analysis. Estimation of binding affinities (∆G) and relative binding free energies (∆∆G) with the linear interaction energy (LIE) method and free energy perturbation (FEP) method showed good general agreement with the observed inhibitory potency. Experimental and calculated data highlight the cumulative importance of an intact N-terminal peptide, the specific nature of the macrocycle, the phenolic oxygen and the C-terminal functionality.
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| 6. |
- Belfrage, Anna Karin, 1977-
(författare)
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Design and Synthesis of Hepatitis C Virus NS3 Protease Inhibitors : Targeting Different Genotypes and Drug-Resistant Variants
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Since the first approved hepatitis C virus (HCV) NS3 protease inhibitors in 2011, numerous direct acting antivirals (DAAs) have reached late stages of clinical trials. Today, several combination therapies, based on different DAAs, with or without the need of pegylated interferon-α injection, are available for chronic HCV infections. The chemical foundation of the approved and late-stage HCV NS3 protease inhibitors is markedly similar. This could partly explain the cross-resistance that have emerged under the pressure of NS3 protease inhibitors. The first-generation NS3 protease inhibitors were developed to efficiently inhibit genotype 1 of the virus and were less potent against other genotypes.The main focus in this thesis was to design and synthesize a new class of 2(1H)-pyrazinone based HCV NS3 protease inhibitors, structurally dissimilar to the inhibitors evaluated in clinical trials or approved, potentially with a unique resistance profile and with a broad genotypic coverage. Successive modifications were performed around the pyrazinone core structure to clarify the structure-activity relationship; a P3 urea capping group was found valuable for inhibitory potency, as were elongated R6 residues possibly directed towards the S2 pocket. Dissimilar to previously developed inhibitors, the P1’ aryl acyl sulfonamide was not essential for inhibition as shown by equally good inhibitory potency for P1’ truncated inhibitors. In vitro pharmacokinetic (PK) evaluations disclosed a marked influence from the R6 moiety on the overall drug-properties and biochemical evaluation of the inhibitors against drug resistant enzyme variants showed retained inhibitory potency as compared to the wild-type enzyme. Initial evaluation against genotype 3a displayed micro-molar potencies. Lead optimization, with respect to improved PK properties, were also performed on an advanced class of HCV NS3 protease inhibitors, containing a P2 quinazoline substituent in combination with a macro-cyclic proline urea scaffold with nano-molar cell based activities.Moreover, an efficient Pd-catalyzed C-N urea arylation protocol, enabling high yielding introductions of advanced urea substituents to the C3 position of the pyrazinone, and a Pd-catalyzed carbonylation procedure, to obtain acyl sulfinamides, were developed. These methods can be generally applicable in the synthesis of bioactive compounds containing peptidomimetic scaffolds and carboxylic acid bioisosteres.
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| 7. |
- Belfrage, Anna Karin, et al.
(författare)
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Discovery of pyrazinone based compounds that potently inhibit the drug resistant enzyme variant R155K of the hepatitis C virus NS3 protease
- 2016
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 24:12, s. 2603-2620
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we present the design and synthesis of 2(1H)-pyrazinone based HCV NS3 protease inhibitors with variations in the C-terminus. Biochemical evaluation was performed using genotype 1a, both the wildtype and the drug resistant enzyme variant, R155K. Surprisingly, compounds without an acidic sulfonamide retained good inhibition, challenging our previous molecular docking model. Moreover, selected compounds in this series showed nanomolar potency against R155K NS3 protease; which generally confer resistance to all HCV NS3 protease inhibitors approved or in clinical trials. These results further strengthen the potential of this novel substance class, being very different to the approved drugs and clinical candidates, in the development of inhibitors less sensitive to drug resistance.
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| 8. |
- Belfrage, Anna Karin, 1977-, et al.
(författare)
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Efficient and Selective Palladium-Catalysed C-3 Urea Couplings to 3,5-Dichloro-2(1H)-pyrazinones
- 2015
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Ingår i: European Journal of Organic Chemistry. - : Wiley. - 1434-193X .- 1099-0690. ; :5, s. 978-986
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Tidskriftsartikel (refereegranskat)abstract
- The development of a robust palladium-catalysed urea N-arylation protocol to install various ureas at the 3-position of the 2(1H)-pyrazinone scaffold is described. The method involves Pd(OAc)2 in combination with bidentate ligands, xantphos [4,5-bis(diphenylphosphino)-9,9-dimethylxanthene] in particular, and resulted in good to excellent coupling yields of aliphatic, aromatic, and sterically hindered ureas. Furthermore, the C-3 chlorine was shown to be selectively displaced in the presence of aryl halide ureas, and this finding was supported by density functional theory (DFT) calculations. This allows further diversification of the scaffold for the production of compound libraries. Overall, the protocol facilitates further exploitation of pyrazinones as beta-sheet-inducing scaffolds in the development of sophisticated peptidomimetics/protease inhibitors. This is exemplified here by the synthesis of a new pyrazinone-based hepatitis C virus (HCV) NS3 protease inhibitor.
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