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Dao VTV, Elbatreek MH, Fuchß T, Grädler U, Schmidt HHHW, Shah AM, Wallace A, Knowles R. Nitric Oxide Synthase Inhibitors into the Clinic at Last. Handb Exp Pharmacol 2021; 264:169-204. [PMID: 32797331 DOI: 10.1007/164_2020_382] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The 1998 Nobel Prize in Medicine and Physiology for the discovery of nitric oxide, a nitrogen containing reactive oxygen species (also termed reactive nitrogen or reactive nitrogen/oxygen species) stirred great hopes. Clinical applications, however, have so far pertained exclusively to the downstream signaling of cGMP enhancing drugs such as phosphodiesterase inhibitors and soluble guanylate cyclase stimulators. All clinical attempts, so far, to inhibit NOS have failed even though preclinical models were strikingly positive and clinical biomarkers correlated perfectly. This rather casts doubt on our current way of target identification in drug discovery in general and our way of patient stratification based on correlating but not causal biomarkers or symptoms. The opposite, NO donors, nitrite and enhancing NO synthesis by eNOS/NOS3 recoupling in situations of NO deficiency, are rapidly declining in clinical relevance or hold promise but need yet to enter formal therapeutic guidelines, respectively. Nevertheless, NOS inhibition in situations of NO overproduction often jointly with enhanced superoxide (or hydrogen peroxide production) still holds promise, but most likely only in acute conditions such as neurotrauma (Stover et al., J Neurotrauma 31(19):1599-1606, 2014) and stroke (Kleinschnitz et al., J Cereb Blood Flow Metab 1508-1512, 2016; Casas et al., Proc Natl Acad Sci U S A 116(14):7129-7136, 2019). Conversely, in chronic conditions, long-term inhibition of NOS might be too risky because of off-target effects on eNOS/NOS3 in particular for patients with cardiovascular risks or metabolic and renal diseases. Nitric oxide synthases (NOS) and their role in health (green) and disease (red). Only neuronal/type 1 NOS (NOS1) has a high degree of clinical validation and is in late stage development for traumatic brain injury, followed by a phase II safety/efficacy trial in ischemic stroke. The pathophysiology of NOS1 (Kleinschnitz et al., J Cereb Blood Flow Metab 1508-1512, 2016) is likely to be related to parallel superoxide or hydrogen peroxide formation (Kleinschnitz et al., J Cereb Blood Flow Metab 1508-1512, 2016; Casas et al., Proc Natl Acad Sci U S A 114(46):12315-12320, 2017; Casas et al., Proc Natl Acad Sci U S A 116(14):7129-7136, 2019) leading to peroxynitrite and protein nitration, etc. Endothelial/type 3 NOS (NOS3) is considered protective only and its inhibition should be avoided. The preclinical evidence for a role of high-output inducible/type 2 NOS (NOS2) isoform in sepsis, asthma, rheumatic arthritis, etc. was high, but all clinical development trials in these indications were neutral despite target engagement being validated. This casts doubt on the role of NOS2 in humans in health and disease (hence the neutral, black coloring).
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Affiliation(s)
- Vu Thao-Vi Dao
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Mahmoud H Elbatreek
- Department of Pharmacology and Personalised Medicine, MeHNS, FHML, Maastricht, The Netherlands.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Thomas Fuchß
- Takeda GmbH (former Nycomed/Altana Pharma), Konstanz, Germany
| | - Ulrich Grädler
- Takeda GmbH (former Nycomed/Altana Pharma), Konstanz, Germany
| | - Harald H H W Schmidt
- Department of Pharmacology and Personalised Medicine, MeHNS, FHML, Maastricht, The Netherlands
| | - Ajay M Shah
- King's College London British Heart Foundation Centre, School of Cardiovascular Medicine and Sciences, London, UK
| | - Alan Wallace
- Health and Life Sciences, Coventry University, Coventry, UK
| | - Richard Knowles
- Knowles Consulting Ltd., The Stevenage Bioscience Catalyst, Stevenage, UK.
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Mirgorodskaya AB, Kuznetsova DA, Kushnazarova RA, Gabdrakhmanov DR, Zhukova NA, Lukashenko SS, Sapunova AS, Voloshina AD, Sinyashin OG, Mamedov VA, Zakharova LY. Soft nanocarriers for new poorly soluble conjugate of pteridine and benzimidazole: Synthesis and cytotoxic activity against tumor cells. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Casas AI, Nogales C, Mucke HAM, Petraina A, Cuadrado A, Rojo AI, Ghezzi P, Jaquet V, Augsburger F, Dufrasne F, Soubhye J, Deshwal S, Di Sante M, Kaludercic N, Di Lisa F, Schmidt HHHW. On the Clinical Pharmacology of Reactive Oxygen Species. Pharmacol Rev 2020; 72:801-828. [DOI: 10.1124/pr.120.019422] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Abbas ZAA, Abu-Mejdad NMJ, Atwan ZW, Al-Masoudi NA. Synthesis and Biological Evaluation of New Dipyridylpteridines, Lumazines, and Related Analogues. J Heterocycl Chem 2016. [DOI: 10.1002/jhet.2651] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Zina A. A. Abbas
- Department of Chemistry, College of Science; University of Basrah; Basrah Iraq
- Central Laboratories, Rumaila; Southern Oil Company; Basrah Iraq
| | | | - Zeenah W. Atwan
- Department of Biology, College of Science; University of Basrah; Basrah Iraq
| | - Najim A. Al-Masoudi
- Department of Chemistry, College of Science; University of Basrah; Basrah Iraq
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Rochette L, Lorin J, Zeller M, Guilland JC, Lorgis L, Cottin Y, Vergely C. Nitric oxide synthase inhibition and oxidative stress in cardiovascular diseases: Possible therapeutic targets? Pharmacol Ther 2013; 140:239-57. [DOI: 10.1016/j.pharmthera.2013.07.004] [Citation(s) in RCA: 269] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 06/14/2013] [Indexed: 12/14/2022]
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Kunuthur SP, Milliken PH, Gibson CL, Suckling CJ, Wadsworth RM. Tetrahydrobiopterin analogues with NO-dependent pulmonary vasodilator properties. Eur J Pharmacol 2011; 650:371-7. [PMID: 20950600 DOI: 10.1016/j.ejphar.2010.09.070] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 09/02/2010] [Accepted: 09/23/2010] [Indexed: 10/19/2022]
Abstract
Reduced NO levels due to the deficiency of tetrahydrobiopterin (BH(4)) contribute to impaired vasodilation in pulmonary hypertension. Due to the chemically unstable nature of BH(4), it was hypothesised that oxidatively stable analogues of BH(4) would be able to support NO synthesis to improve endothelial dysfunction in pulmonary hypertension. Two analogues of BH(4), namely 6-hydroxymethyl pterin (HMP) and 6-acetyl-7,7-dimethyl-7,8-dihydropterin (ADDP), were evaluated for vasodilator activity on precontracted rat pulmonary artery rings. ADDP was administered to pulmonary hypertensive rats, followed by measurement of pulmonary vascular resistance in perfused lungs and eNOS expression by immunohistochemistry. ADDP and HMP caused significant relaxation in vitro in rat pulmonary arteries depleted of BH(4) with a maximum relaxation at 0.3μM (both P<0.05). Vasodilator activity of ADDP and HMP was completely abolished following preincubation with the NO synthase inhibitor, L-NAME. ADDP and HMP did not alter relaxation induced by carbachol or spermine NONOate. BH(4) itself did not produce relaxation. In rats receiving ADDP 14.1mg/kg/day, pulmonary vasodilation induced by calcium ionophore A23187 was augmented and eNOS immunoreactivity was increased. In conclusion, ADDP and HMP are two analogues of BH(4), which can act as oxidatively stable alternatives to BH(4) in causing NO-mediated vasorelaxation. Chronic treatment with ADDP resulted in improvement of NO-mediated pulmonary artery dilation and enhanced expression of eNOS in the pulmonary vascular endothelium. Chemically stable analogues of BH(4) may be able to limit endothelial dysfunction in the pulmonary vasculature.
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Affiliation(s)
- Suma P Kunuthur
- Strathclyde Institute of Pharmacy and Biomedical Sciences, UK
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Al-Masoudi NA, Saleh BA, Karim NA, Issa AY, Pannecouque C. Synthesis and anti-HIV activity of new 2-thiolumazine and 2-thiouracil metal complexes. HETEROATOM CHEMISTRY 2010. [DOI: 10.1002/hc.20654] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Glazer EC, Nguyen YHL, Gray HB, Goodin DB. Probing inducible nitric oxide synthase with a pterin-ruthenium(II) sensitizer wire. Angew Chem Int Ed Engl 2008; 47:898-901. [PMID: 18085539 DOI: 10.1002/anie.200703743] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Edith C Glazer
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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Suckling CJ, Gibson CL, Huggan JK, Morthala RR, Clarke B, Kununthur S, Wadsworth RM, Daff S, Papale D. 6-Acetyl-7,7-dimethyl-5,6,7,8-tetrahydropterin is an activator of nitric oxide synthases. Bioorg Med Chem Lett 2008; 18:1563-6. [DOI: 10.1016/j.bmcl.2008.01.079] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 01/22/2008] [Accepted: 01/22/2008] [Indexed: 11/28/2022]
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Glazer E, Nguyen Y, Gray H, Goodin D. Probing Inducible Nitric Oxide Synthase with a Pterin–Ruthenium(II) Sensitizer Wire. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200703743] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Mechanism of the inhibition of calmodulin-dependent neuronal nitric oxide synthase by flaxseed protein hydrolysates. J AM OIL CHEM SOC 2006. [DOI: 10.1007/s11746-006-1209-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Matter H, Kumar HSA, Fedorov R, Frey A, Kotsonis P, Hartmann E, Fröhlich LG, Reif A, Pfleiderer W, Scheurer P, Ghosh DK, Schlichting I, Schmidt HHHW. Structural analysis of isoform-specific inhibitors targeting the tetrahydrobiopterin binding site of human nitric oxide synthases. J Med Chem 2005; 48:4783-92. [PMID: 16033258 DOI: 10.1021/jm050007x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nitric oxide synthesized from l-arginine by nitric oxide synthase isoforms (NOS-I-III) is physiologically important but also can be deleterious when overproduced. Selective NOS inhibitors are of clinical interest, given their differing pathophysiological roles. Here we describe our approach to target the unique NOS (6R,1'R,2'S)-5,6,7,8-tetrahydrobiopterin (H(4)Bip) binding site. By a combination of ligand- and structure-based design, the structure-activity relationship (SAR) for a focused set of 41 pteridine analogues on four scaffolds was developed, revealing selective NOS-I inhibitors. The X-ray crystal structure of rat NOS-I dimeric-oxygenase domain with H(4)Bip and l-arginine was determined and used for human isoform homology modeling. All available NOS structural information was subjected to comparative analysis of favorable protein-ligand interactions using the GRID/concensus principal component analysis (CPCA) approach to identify the isoform-specific interaction site. Our interpretation, based on protein structures, is in good agreement with the ligand SAR and thus permits the rational design of next-generation inhibitors targeting the H(4)Bip binding site with enhanced isoform selectivity for therapeutics in pathology with NO overproduction.
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Affiliation(s)
- Hans Matter
- Sanofi-Aventis, Chemical Sciences, Drug Design, Building G 878, D-65926 Frankfurt am Main, Germany
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Bengea SN, Araki Y, Ito O, Igarashi J, Kurokawa H, Shimizu T. Dual Effects of the Substrate and Pterins on the Kinetics of CO Binding to Neuronal Nitric Oxide Synthase: A Laser Flash Photolysis Study. CHEM LETT 2005. [DOI: 10.1246/cl.2005.752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Teigen K, Dao KK, McKinney JA, Gorren ACF, Mayer B, Frøystein NA, Haavik J, Martínez A. Tetrahydrobiopterin binding to aromatic amino acid hydroxylases. Ligand recognition and specificity. J Med Chem 2004; 47:5962-71. [PMID: 15537351 DOI: 10.1021/jm0497646] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The three aromatic amino acid hydroxylases (phenylalanine, tyrosine, and tryptophan hydroxylase) and nitric oxide synthase (NOS) all utilize (6R)-l-erythro-5,6,7,8-tetrahydrobiopterin (BH(4)) as cofactor. The pterin binding site in the three hydroxylases is well conserved and different from the binding site in NOS. The structures of phenylalanine hydroxylase (PAH) and of NOS in complex with BH(4) are still the only crystal structures available for the reduced cofactor-enzyme complexes. We have studied the enzyme-bound and free conformations of BH(4) by NMR spectroscopy and molecular docking into the active site of the three hydroxylases, using endothelial NOS as a comparative probe. We have found that the dihydroxypropyl side chain of BH(4) adopts different conformations depending on which hydroxylase it interacts with. All the bound conformations are different from that of BH(4) free in solution at neutral pH. The different bound conformations appear to result from specific interactions with nonconserved amino acids at the BH(4) binding sites of the hydroxylases, notably the stretch 248-251 (numeration in PAH) and the residue corresponding to Ala322 in PAH, i.e., Ser in TH and Ala in TPH. On the basis of analysis of molecular interaction fields, we discuss the selectivity determinants for each hydroxylase and explain the high-affinity inhibitory effect of 7-tetrahydrobiopterin specifically for PAH.
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Affiliation(s)
- Knut Teigen
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009-Bergen, Norway
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Matter H, Kotsonis P. Biology and chemistry of the inhibition of nitric oxide synthases by pteridine-derivatives as therapeutic agents. Med Res Rev 2004; 24:662-84. [PMID: 15224385 DOI: 10.1002/med.20005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Inhibitors of the family of nitric oxide synthases (NOS-I-III; EC 1.14.13.39) are of interest as pharmacological agents to modulate pathologically high nitric oxide (NO) levels in inflammation, sepsis, and stroke. In this article, we discuss the approach for targeting the unique (6R)-5,6,7,8-tetrahydro-L-biopterin (H4Bip) binding site of NOS by appropriate inhibitors. This binding site maximally increases enzyme activity and NO production from the substrate L-arginine upon cofactor binding. The first generation of H4Bip-based NOS inhibitors was based on 4-amino H4Bip derivatives in analogy to anti-folates such as methotrexate. In addition, we discuss the structure-activity relationship of a related series of 4-oxo-pteridine derivatives. Furthermore, molecular modeling studies provide an understanding of pterin antagonism on a structural level based on favorable and unfavorable interactions between protein binding site and ligands. These techniques include 3D-QSAR (CoMFA, CoMSIA) to understand ligand affinity and GRID/consensus principal component analysis (CPCA) to learn about selectivity requirements. Collectively these approaches, in combination with the presented SAR and structural data, provide useful information for the design of novel NOS inhibitors with increased isoform selectivity.
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Affiliation(s)
- Hans Matter
- Aventis Pharma Deutschland GmbH, DI&A Chemistry, Molecular Modelling, Building G 878, D-65926, Frankfurt am Main, Germany.
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16
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Affiliation(s)
- Charles J Reedy
- Department of Chemistry, Columbia University, 3000 Broadway, MC 3121, New York, New York 10027, USA
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Gautier C, Négrerie M, Wang ZQ, Lambry JC, Stuehr DJ, Collin F, Martin JL, Slama-Schwok A. Dynamic regulation of the inducible nitric-oxide synthase by NO: comparison with the endothelial isoform. J Biol Chem 2004; 279:4358-65. [PMID: 14594819 DOI: 10.1074/jbc.m305048200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We studied by ultrafast time-resolved absorption spectroscopy the geminate recombination of NO to the oxygenase domain of the inducible NO synthase, iNOSoxy, and to mutated proteins at position Trp-457. This tryptophan interacts with the tetrahydrobiopterin cofactor BH4, and W457A/F mutations largely reduced the catalytic formation of NO. BH4 decreases the rate of NO rebinding to the ferric iNOSoxy compared with that measured in its absence. The pterin has a larger effect on W457A/F than on the WT protein by increasing NO release from the protein. Therefore, BH4 raises the energy barrier for NO recombination to the mutated proteins in contrast with our observations on eNOS (Slama-Schwok, A., Négrerie, M., Berka, V., Lambry, J.-C., Tsai, A.-L., Vos, M., and Martin, J.-L. (2002) J. Biol. Chem. 277, 7581-7586). Thus, we show a differential effect of BH4 on NO release from eNOS and iNOS. Compared with the position of this residue in the BH4-repleted enzyme, simulations of the NO dissociation dynamics point out at a swing of Trp-457 toward the missing pterin in the absence of BH4. NO geminate-rebinding data show a more efficient NO release from eNOS than from iNOS once NO is formed. Consistently, NO produced by iNOS is regulated by its ferric nitrosyl complex in contrast with eNOS. We show that the small enhancement of the NO geminate recombination rate in W457A/F compared with that in the WT enzyme cannot explain the decrease of NO yield because of the mutation; the major effect of the mutation thus arises from an uncoupled catalysis (Wang, Z. Q., Wei, C. C., Ghosh, S., Meade, A. L., Hemann, C., Hille, R., and Stuehr, D. J. (2001) Biochemistry 40, 12819-12825).
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Affiliation(s)
- Clement Gautier
- Laboratory for Optics and Biosciences, INSERM U451, CNRS Unite Mixte de Recherche 7645, Ecole Polytechnique, 91128 Palaiseau Cedex, France
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Ji H, Li H, Flinspach M, Poulos TL, Silverman RB. Computer modeling of selective regions in the active site of nitric oxide synthases: implication for the design of isoform-selective inhibitors. J Med Chem 2004; 46:5700-11. [PMID: 14667223 DOI: 10.1021/jm030301u] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Selective inhibition of nitric oxide synthase (NOS) isoforms has great therapeutic potential in the treatment of certain disease states arising from the pathological overproduction of nitric oxide. In this study three structures of each NOS isoform were employed to examine selective regions in the active site using the GRID/CPCA approach. In the GRID calculations, 10 probes covering hydrophobic, steric, and hydrogen-bond-acceptor and -donor interactions were used to calculate the molecular interaction fields (MIFs) in the active site. The side chain flexibility of the residues and the grid spacings were considered at the same time. Consensus principal component analysis (CPCA) was applied to analyze the MIFs differences in the active site between the NOS isoforms. By combining the cutout tool with GRID/CPCA pseudofield differential plots, several selective regions in the active site were identified. The selectivity analysis showed that the most important determinants for NOS inhibitor selectivity are hydrophobic and charge-charge interactions. Twenty-five inhibitors of NOS were then docked into the active site using the program AutoDock3.0. The regions identified as being important for selectivity by this method are in excellent agreement with inhibitor structure-activity relationships. A rational usage of the selective region described in this work should make it possible to develop NOS isoform-selective inhibitors.
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Affiliation(s)
- Haitao Ji
- Department of Chemistry, Northwestern University, Evanston, IL 60208-3113, USA
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Werner ER, Gorren ACF, Heller R, Werner-Felmayer G, Mayer B. Tetrahydrobiopterin and nitric oxide: mechanistic and pharmacological aspects. Exp Biol Med (Maywood) 2003; 228:1291-302. [PMID: 14681545 DOI: 10.1177/153537020322801108] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In previous minireviews in this journal, we discussed work on induction of tetrahydrobiopterin biosynthesis by cytokines and its significance for nitric oxide (NO) production of intact cells as well as functions of H4-biopterin identified at this time for NO synthases (Proc Soc Exp Biol Med 203: 1-12, 1993; Proc Soc Exp Biol Med 219: 171-182, 1998). Meanwhile, the recognition of the importance of tetrahydrobiopterin for NO formation has led to new insights into complex biological processes and revealed possible novel pharmacological strategies to intervene in certain pathological conditions. Recent work could also establish that tetrahydrobiopterin, in addition to its allosteric effects, is redox-active in the NO synthase reaction. In this review, we summarize the current view of how tetrahydrobiopterin functions in the generation of NO and focus on pharmacological aspects of tetrahydrobiopterin availability with emphasis on endothelial function.
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Affiliation(s)
- Ernst R Werner
- Institute for Medical Chemistry and Biochemistry, University of Innsbruck, A-6020 Innsbruck, Austria.
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Fedorov R, Hartmann E, Ghosh DK, Schlichting I. Structural basis for the specificity of the nitric-oxide synthase inhibitors W1400 and Nomega-propyl-L-Arg for the inducible and neuronal isoforms. J Biol Chem 2003; 278:45818-25. [PMID: 12954642 DOI: 10.1074/jbc.m306030200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The high level of amino acid conservation and structural similarity in the immediate vicinity of the substrate binding sites of the oxygenase domains of the nitric-oxide synthase (NOS) isoforms (eNOSoxy, iNOSoxy, and nNOSoxy) make the interpretation of the structural basis of inhibitor isoform specificity a challenge and provide few clues for the design of new selective compounds. Crystal structures of iNOSoxy and nNOSoxy complexed with the inhibitors W1400 and Nomega-propyl-l-arginine provide a rationale for their isoform specificity. It involves differences outside the immediate active site as well as a conformational flexibility in the active site that allows the adoption of distinct conformations in response to interactions with the inhibitors. This flexibility is determined by isoform-specific residues outside the active site.
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Affiliation(s)
- Roman Fedorov
- Max Planck Institut für Molekulare Physiologie, Abteilung Biophysikalische Chemie, Otto Hahn Strasse 11, 44227 Dortmund, Germany
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Affiliation(s)
- Chin-Chuan Wei
- Department of Immunology, The Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Wei CC, Wang ZQ, Arvai AS, Hemann C, Hille R, Getzoff ED, Stuehr DJ. Structure of tetrahydrobiopterin tunes its electron transfer to the heme-dioxy intermediate in nitric oxide synthase. Biochemistry 2003; 42:1969-77. [PMID: 12590583 DOI: 10.1021/bi026898h] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
How 6R-tetrahydrobiopterin (H(4)B) participates in Arg hydroxylation as catalyzed by the nitric oxide synthases (NOSs) is a topic of current interest. Previous work with the oxygenase domain of inducible NOS (iNOSoxy) demonstrated that H(4)B radical formation is kinetically coupled to disappearance of an initial heme-dioxy intermediate and to Arg hydroxylation in a single turnover reaction run at 10 degrees C [Wei, C.-C., Wang, Z.-Q., Wang, Q., Meade, A. L., Hemann, C., Hille, R., and Stuehr, D. J. (2001) J. Biol. Chem. 276, 315-319]. Here we used 5-methyl-H(4)B to investigate how pterin structure influences radical formation and associated catalytic steps. In the presence of Arg, the heme-dioxy intermediate in 5-methyl-H(4)B-bound iNOSoxy reacted at a rate of 35 s(-)(1), which is 3-fold faster than with H(4)B. This was coupled to a faster rate of 5-methyl-H(4)B radical formation (40 vs 12.5 s(-)(1)) and to a faster and more productive Arg hydroxylation. The EPR spectrum of the enzyme-bound 5-methyl-H(4)B radical had different hyperfine structure than the bound H(4)B radical and exhibited a 3-fold longer half-life after its formation. A crystal structure of 5-methyl-H(4)B-bound iNOSoxy revealed that there are minimal changes in conformation of the bound pterin or in its interactions with the protein as compared to H(4)B. Together, we conclude the following: (1) The rate of heme-dioxy reduction is linked to pterin radical formation and is sensitive to pterin structure. (2) Faster heme-dioxy reduction increases the efficiency of Arg hydroxylation but still remains rate limiting for the reaction. (3) The 5-methyl group influences heme-dioxy reduction by altering the electronic properties of the pterin rather than changing protein structure or interactions. (4) Faster electron transfer from 5-methyl-H(4)B may be due to increased radical stability afforded by the N-5 methyl group.
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Affiliation(s)
- Chin-Chuan Wei
- Department of Immunology, The Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Matter H, Kotsonis P, Klingler O, Strobel H, Fröhlich LG, Frey A, Pfleiderer W, Schmidt HHHW. Structural requirements for inhibition of the neuronal nitric oxide synthase (NOS-I): 3D-QSAR analysis of 4-oxo- and 4-amino-pteridine-based inhibitors. J Med Chem 2002; 45:2923-41. [PMID: 12086480 DOI: 10.1021/jm020074g] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The family of homodimeric nitric oxide synthases (NOS I-III) catalyzes the generation of the cellular messenger nitric oxide (NO) by oxidation of the substrate L-arginine. The rational design of specific NOS inhibitors is of therapeutic interest in regulating pathological NO levels associated with sepsis, inflammatory, and neurodegenerative diseases. The cofactor (6R)-5,6,7,8-tetrahydrobiopterin (H(4)Bip) maximally activates all NOSs and stabilizes enzyme quaternary structure by promoting and stabilizing dimerization. Here, we describe the synthesis and three-dimensional (3D) quantitative structure-activity relationship (QSAR) analysis of 65 novel 4-amino- and 4-oxo-pteridines (antipterins) as inhibitors targeting the H(4)Bip binding site of the neuronal NOS isoform (NOS-I). The experimental binding modes for two inhibitors complexed with the related endothelial NO synthase (NOS-III) reveal requirements of biological affinity and form the basis for ligand alignment. Different alignment rules were derived by building other compounds accordingly using manual superposition or a genetic algorithm for flexible superposition. Those alignments led to 3D-QSAR models (comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA)), which were validated using leave-one-out cross-validation, multiple analyses with two and five randomly chosen cross-validation groups, perturbation of biological activities by randomization or progressive scrambling, and external prediction. An iterative realignment procedure based on rigid field fit was used to improve the consistency of the resulting partial least squares models. This led to consistent and highly predictive 3D-QSAR models with good correlation coefficients for both CoMFA and CoMSIA, which correspond to experimentally determined NOS-II and -III H(4)Bip binding site topologies as well as to the NOS-I homology model binding site in terms of steric, electrostatic, and hydrophobic complementarity. These models provide clear guidelines and accurate activity predictions for novel NOS-I inhibitors.
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Affiliation(s)
- Hans Matter
- Molecular Modeling, Aventis Pharma, G 878, 65926 Frankfurt am Main, Germany.
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