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Yan L, Wang Y, Zhang S, Li X, Wei J, Wang Z, Liu Y. Inactivation Mechanism of Neuronal Nitric Oxide Synthase by ( S)-2-Amino-5-(2-(methylthio)acetimidamido)pentanoic Acid: Chemical Conversion of the Inactivator in the Active Site. Inorg Chem 2021; 60:9345-9358. [PMID: 34137256 DOI: 10.1021/acs.inorgchem.1c00046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Neuronal nitric oxide synthase (nNOS) is one of the three isoforms of nitric oxide synthase (NOS). The other two isoforms include inducible NOS (iNOS) and endothelial NOS (eNOS). These three isoforms of NOS are widely present in both human and other mammals and are responsible for the biosynthesis of NO. As an essential biological molecule, NO plays an essential role in neurotransmission, immune response, and vasodilation; however, the overproduction of NO can cause a series of diseases. Thus, the selective inhibition of three isoforms of NOS has been considered to be important in treating related diseases. The active sites of the three enzymes are highly conserved, causing the selective inhibition of the three enzymes to be a great challenge. (S)-2-Amino-5-(2-(methylthio)acetimidamido)pentanoic acid (1) has been experimentally proved to be a selective and time-dependent irreversible inhibitor of nNOS, and three pathways, including sulfide oxidation, oxidative dethiolation, and oxidative demethylation, have been suggested. In this work, we performed quantum mechanics/molecular mechanics calculations to verify the chemical conversion of inactivator 1. Although we agree with the previously suggested chemical transformation process, our calculations demonstrated that there are lower energy pathways to accomplish both oxidative dethiolation and oxidative demethylation. These three branching reactions are competitive, but only dethiolation and demethylation reactions can generate inhibitory intermediates. As a powerful time-dependent irreversible inhibitor of nNOS, the key sulfur atom and middle imine are all necessary. Our calculation results not only verified the chemical reaction of inhibitor 1 occurring in the enzymatic active site but also explained the inactivation mechanism of inhibitor 1. This is also the first verified example of the heme-enzyme-catalyzed S-demethylation mechanism.
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Affiliation(s)
- Lijuan Yan
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yijing Wang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Shiqing Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Xinyi Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Jingjing Wei
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Zhiguo Wang
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yongjun Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
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Mittal A, Kakkar R. Nitric Oxide Synthases and Their Inhibitors: A Review. LETT DRUG DES DISCOV 2020. [DOI: 10.2174/1570180816666190222154457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nitric Oxide (NO), an important biological mediator, is involved in the regulation of the cardiovascular, nervous and immune systems in mammals. Synthesis of NO is catalyzed by its biosynthetic enzyme, Nitric Oxide Synthase (NOS). There are three main isoforms of the enzyme, neuronal NOS, endothelial NOS and inducible NOS, which have very similar structures but differ in their expression and activities. NO is produced in the active site of the enzyme in two distinct cycles from oxidation of the substrate L-arg (L-arginine) in nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reaction. NOS has gained considerable attention of biochemists due to its complexity and unique catalytic mechanism. The review focuses on NOS structure, its function and catalytic reaction mechanism. In particular, the review is concluded with a discussion on the role of all three isoforms of NOS in physiological and pathological conditions and their inhibitors with a focus on the role of computational techniques in their development.
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Affiliation(s)
- Anshika Mittal
- Computational Chemistry Laboratory, Department of Chemistry, University of Delhi, Delhi-110007, India
| | - Rita Kakkar
- Computational Chemistry Laboratory, Department of Chemistry, University of Delhi, Delhi-110007, India
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3
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Kumar Y, Shaw M, Thakur R, Kumar A. Copper(II)-Mediated Aerobic Oxidation of Benzylimidates: Synthesis of Primary α-Ketoamides. J Org Chem 2016; 81:6617-25. [DOI: 10.1021/acs.joc.6b01262] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Yogesh Kumar
- Department
of Chemistry, Indian Institute of Technology Patna, Bihta 801103, Bihar, India
| | - Mukta Shaw
- Department
of Chemistry, Indian Institute of Technology Patna, Bihta 801103, Bihar, India
| | - Rima Thakur
- Department
of Chemistry, National Institute of Technology Patna, Patna 800005, Bihar, India
| | - Amit Kumar
- Department
of Chemistry, Indian Institute of Technology Patna, Bihta 801103, Bihar, India
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4
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Tang W, Li H, Doud EH, Chen Y, Choing S, Plaza C, Kelleher NL, Poulos TL, Silverman RB. Mechanism of Inactivation of Neuronal Nitric Oxide Synthase by (S)-2-Amino-5-(2-(methylthio)acetimidamido)pentanoic Acid. J Am Chem Soc 2015; 137:5980-9. [PMID: 25874809 PMCID: PMC4431946 DOI: 10.1021/jacs.5b01202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nitric oxide synthase (NOS) catalyzes the conversion of l-arginine to l-citrulline and the second messenger nitric oxide. Three mechanistic pathways are proposed for the inactivation of neuronal NOS (nNOS) by (S)-2-amino-5-(2-(methylthio)acetimidamido)pentanoic acid (1): sulfide oxidation, oxidative dethiolation, and oxidative demethylation. Four possible intermediates were synthesized. All compounds were assayed with nNOS, their IC50, KI, and kinact values were obtained, and their crystal structures were determined. The identification and characterization of the products formed during inactivation provide evidence for the details of the inactivation mechanism. On the basis of these studies, the most probable mechanism for the inactivation of nNOS involves oxidative demethylation with the resulting thiol coordinating to the cofactor heme iron. Although nNOS is a heme-containing enzyme, this is the first example of a NOS that catalyzes an S-demethylation reaction; the novel mechanism of inactivation described here could be applied to the design of inactivators of other heme-dependent enzymes.
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Affiliation(s)
- Wei Tang
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Huiying Li
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences, University of California, Irvine, California 92697-3900, United States
| | - Emma H. Doud
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Proteomics Center of Excellence, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Yunqiu Chen
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Proteomics Center of Excellence, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Stephanie Choing
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Carla Plaza
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences, University of California, Irvine, California 92697-3900, United States
| | - Neil L. Kelleher
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Proteomics Center of Excellence, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Thomas L. Poulos
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences, University of California, Irvine, California 92697-3900, United States
| | - Richard B. Silverman
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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5
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Tang W, Li H, Poulos TL, Silverman RB. Mechanistic studies of inactivation of inducible nitric oxide synthase by amidines. Biochemistry 2015; 54:2530-8. [PMID: 25811913 DOI: 10.1021/acs.biochem.5b00135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Nitric oxide synthase (NOS) catalyzes the conversion of L-arginine to L-citrulline and nitric oxide. N(5)-(1-Iminoethyl)-L-ornithine (L-NIO), an amidine-containing molecule, is a natural product known to be an inactivator of inducible NOS (iNOS). Because of the presence of the amidine methyl group in place of the guanidine amino group of substrate L-arginine, the active site heme peroxy intermediate sometimes cannot be protonated, thereby preventing its conversion to the heme oxo intermediate; instead, a heme oxygenase-type mechanism occurs, leading to conversion of the heme to biliverdin. This might be a new and general inactivation mechanism for heme-containing enzymes. In the studies described here, we attempted to provide support for amidines as substrates and inactivators of iNOS by the design and synthesis of amidine analogues of L-NIO having groups other than the amidine methyl group. No nitric oxide- or enzyme-catalyzed products could be detected by incubation of these amidines with iNOS. Although none of the L-NIO analogues acted as substrates, they all inhibited iNOS; increased inhibitory potency correlated with decreased substituent size. Computer modeling and molecular dynamics simulations were run on 10 and 11 to rationalize why these compounds do not act as substrates. Unlike the methyl amidine (L-NIO), the other alkyl groups block binding of O2 at the heme iron. Compounds 8, 9, and 11 were inactivators; however, no heme was lost, and no biliverdin was formed. No kinetic isotope effect on inactivation was observed with perdeuterated ethyl 8. A small amount of dimer disruption occurred with these inactivators, although the amount would not account for complete enzyme inactivation. The L-NIO analogues inactivate iNOS by a yet unknown mechanism; however, it is different from that of L-NIO, and the inactivation mechanism previously reported for L-NIO appears to be unique to methyl amidines.
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Affiliation(s)
- Wei Tang
- †Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Huiying Li
- ‡Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences, University of California, Irvine, California 92697-3900, United States
| | - Thomas L Poulos
- ‡Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences, University of California, Irvine, California 92697-3900, United States
| | - Richard B Silverman
- †Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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Mukherjee P, Cinelli MA, Kang S, Silverman RB. Development of nitric oxide synthase inhibitors for neurodegeneration and neuropathic pain. Chem Soc Rev 2014; 43:6814-38. [PMID: 24549364 PMCID: PMC4138306 DOI: 10.1039/c3cs60467e] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Nitric oxide (NO) is an important signaling molecule in the human body, playing a crucial role in cell and neuronal communication, regulation of blood pressure, and in immune activation. However, overproduction of NO by the neuronal isoform of nitric oxide synthase (nNOS) is one of the fundamental causes underlying neurodegenerative disorders and neuropathic pain. Therefore, developing small molecules for selective inhibition of nNOS over related isoforms (eNOS and iNOS) is therapeutically desirable. The aims of this review focus on the regulation and dysregulation of NO signaling, the role of NO in neurodegeneration and pain, the structure and mechanism of nNOS, and the use of this information to design selective inhibitors of this enzyme. Structure-based drug design, the bioavailability and pharmacokinetics of these inhibitors, and extensive target validation through animal studies are addressed.
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Affiliation(s)
- Paramita Mukherjee
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA.
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Víteček J, Lojek A, Valacchi G, Kubala L. Arginine-based inhibitors of nitric oxide synthase: therapeutic potential and challenges. Mediators Inflamm 2012; 2012:318087. [PMID: 22988346 PMCID: PMC3441039 DOI: 10.1155/2012/318087] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 05/30/2012] [Indexed: 12/24/2022] Open
Abstract
In the past three decades, nitric oxide has been well established as an important bioactive molecule implicated in regulation of cardiovascular, nervous, and immune systems. Therefore, it is not surprising that much effort has been made to find specific inhibitors of nitric oxide synthases (NOS), the enzymes responsible for production of nitric oxide. Among the many NOS inhibitors developed to date, inhibitors based on derivatives and analogues of arginine are of special interest, as this category includes a relatively high number of compounds with good potential for experimental as well as clinical application. Though this group of inhibitors covers early nonspecific compounds, modern drug design strategies such as biochemical screening and computer-aided drug design have provided NOS-isoform-specific inhibitors. With an emphasis on major advances in this field, a comprehensive list of inhibitors based on their structural characteristics is discussed in this paper. We provide a summary of their biochemical properties as well as their observed effects both in vitro and in vivo. Furthermore, we focus in particular on their pharmacology and use in recent clinical studies. The potential of newly designed specific NOS inhibitors developed by means of modern drug development strategies is highlighted.
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Affiliation(s)
- Jan Víteček
- International Clinical Research Center-Center of Biomolecular and Cell Engineering, St. Anne's University Hospital Brno, 656 91 Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 612 65 Brno, Czech Republic
| | - Antonín Lojek
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 612 65 Brno, Czech Republic
| | - Giuseppe Valacchi
- Department of Evolutionary Biology, University of Ferrara, 44100 Ferrara, Italy
- Department of Food and Nutrition, Kyung Hee University, Seoul 130-701, Republic of Korea
| | - Lukáš Kubala
- International Clinical Research Center-Center of Biomolecular and Cell Engineering, St. Anne's University Hospital Brno, 656 91 Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 612 65 Brno, Czech Republic
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8
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Lohou E, Sopkova-de Oliveira Santos J, Schumann-Bard P, Boulouard M, Stiebing S, Rault S, Collot V. New hypotheses for the binding mode of 4- and 7-substituted indazoles in the active site of neuronal nitric oxide synthase. Bioorg Med Chem 2012; 20:5296-304. [DOI: 10.1016/j.bmc.2012.06.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 06/11/2012] [Accepted: 06/13/2012] [Indexed: 02/06/2023]
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9
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Doukov T, Li H, Sharma A, Martell JD, Soltis M, Silverman RB, Poulos TL. Temperature-dependent spin crossover in neuronal nitric oxide synthase bound with the heme-coordinating thioether inhibitors. J Am Chem Soc 2011; 133:8326-34. [PMID: 21534614 PMCID: PMC3193996 DOI: 10.1021/ja201466v] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A series of L-arginine analogue nitric oxide synthase inhibitors with a thioether tail have been shown to form an Fe-S thioether interaction as evidenced by continuous electron density between the Fe and S atoms. Even so, the Fe-S thioether interaction was found to be far less important for inhibitor binding than the hydrophobic interactions between the alkyl group in the thioether tail and surrounding protein (Martell et al. J. Am. Chem. Soc. 2010 , 132 , 798). However, among the few thioether inhibitors that showed Fe-S thioether interaction in crystal structures, variations in spin state (high-spin or low-spin) were observed dependent upon the heme iron oxidation state and temperature. Since modern synchrotron X-ray data collection is typically carried out at cryogenic temperatures, we reasoned that some of the discrepancies between cryo-crystal structures and room-temperature UV-visible spectroscopy could be the result of temperature-dependent spin-state changes. We, therefore, have characterized some of these neuronal nitric oxide synthase (nNOS)-thioether inhibitor complexes in both crystal and solution using EPR and UV-visible absorption spectrometry as a function of temperature and the heme iron redox state. We found that some thioether inhibitors switch from high to low spin at lower temperatures similar to the "spin crossover" phenomenon observed in many transition metal complexes.
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Affiliation(s)
- Tzanko Doukov
- Macromolecular Crystallographic Group, Stanford Synchrotron Radiation Lightsource, SLAC, Stanford University, Stanford, California 94309
| | - Huiying Li
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Sciences, and Chemistry, University of California, Irvine, California 92697-3900
| | - Ajay Sharma
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113
| | - Jeffrey D. Martell
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113
| | - Michael Soltis
- Macromolecular Crystallographic Group, Stanford Synchrotron Radiation Lightsource, SLAC, Stanford University, Stanford, California 94309
| | - Richard B. Silverman
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, and Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113
| | - Thomas L. Poulos
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Sciences, and Chemistry, University of California, Irvine, California 92697-3900
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10
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Colpaert F, Mangelinckx S, Kimpe ND. Asymmetric Synthesis of New Chiral β-Amino Acid Derivatives by Mannich-type Reactions of Chiral N-Sulfinyl Imidates with N-Tosyl Aldimines. Org Lett 2010; 12:1904-7. [DOI: 10.1021/ol100073y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Filip Colpaert
- Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Sven Mangelinckx
- Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Norbert De Kimpe
- Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
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11
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Martell JD, Li H, Doukov T, Martásek P, Roman LJ, Soltis M, Poulos TL, Silverman RB. Heme-coordinating inhibitors of neuronal nitric oxide synthase. Iron-thioether coordination is stabilized by hydrophobic contacts without increased inhibitor potency. J Am Chem Soc 2010; 132:798-806. [PMID: 20014790 PMCID: PMC2826131 DOI: 10.1021/ja908544f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The heme-thioether ligand interaction often occurs between heme iron and native methionine ligands, but thioether-based heme-coordinating (type II) inhibitors are uncommon due to the difficulty in stabilizing the Fe-S bond. Here, a thioether-based inhibitor (3) of neuronal nitric oxide synthase (nNOS) was designed, and its binding was characterized by spectrophotometry and crystallography. A crystal structure of inhibitor 3 coordinated to heme iron was obtained, representing, to our knowledge, the first crystal structure of a thioether inhibitor complexed to any heme enzyme. A series of related potential inhibitors (4-8) also were evaluated. Compounds 4-8 were all found to be type I (non-heme-coordinating) inhibitors of ferric nNOS, but 4 and 6-8 were found to switch to type II upon heme reduction to the ferrous state, reflecting the higher affinity of thioethers for ferrous heme than for ferric heme. Contrary to what has been widely thought, thioether-heme ligation was found not to increase inhibitor potency, illustrating the intrinsic weakness of the thioether-ferric heme linkage. Subtle changes in the alkyl groups attached to the thioether sulfur caused drastic changes in the binding conformation, indicating that hydrophobic contacts play a crucial role in stabilizing the thioether-heme coordination.
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Affiliation(s)
- Jeffrey D. Martell
- Department of Chemistry, Department of Biochemistry, Molecular Biology, and Cell Biology, and Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208-3113
| | - Huiying Li
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Chemistry, and Chemistry, University of California, Irvine, California 92697-3900
| | - Tzanko Doukov
- Macromolecular Crystallographic Group, Stanford Synchrotron Radiation Lightsource, SLAC, Stanford University, Stanford, California 94309
| | - Pavel Martásek
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78384-7760
| | - Linda J. Roman
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78384-7760
| | - Michael Soltis
- Macromolecular Crystallographic Group, Stanford Synchrotron Radiation Lightsource, SLAC, Stanford University, Stanford, California 94309
| | - Thomas L. Poulos
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Chemistry, and Chemistry, University of California, Irvine, California 92697-3900
| | - Richard B. Silverman
- Department of Chemistry, Department of Biochemistry, Molecular Biology, and Cell Biology, and Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208-3113
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Synthesis and biological evaluation of 2,4-diaminopteridine derivatives as nitric oxide synthase inhibitor. CHINESE CHEM LETT 2009. [DOI: 10.1016/j.cclet.2008.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Agić D, Hranjec M, Jajcanin N, Starcević K, Karminski-Zamola G, Abramić M. Novel amidino-substituted benzimidazoles: Synthesis of compounds and inhibition of dipeptidyl peptidase III. Bioorg Chem 2007; 35:153-69. [PMID: 17174378 DOI: 10.1016/j.bioorg.2006.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 10/22/2006] [Accepted: 11/03/2006] [Indexed: 11/19/2022]
Abstract
Dipeptidyl peptidase III (DPP III), also known as enkephalinase B, is a zinc-hydrolase with an indicated role in the mammalian pain modulatory system. In order to find a potent antagonist of this enzyme, we synthesized and screened the effect of a small set of benzimidazole derivatives on its activity. To improve the inhibitory potential, a cyclobutane ring was introduced as rigid conformation support to the diamidino substituted dibenzimidazoles. Two such compounds (1' and 4') from the group of cyclobutane derivatives containing amidino-substituted benzimidazole moieties, obtained by photochemical cyclization in water and by respecting rules of the "green chemistry" approach, were found to be strong DPP III inhibitors, with IC(50) value below 5 microM. Compound 1' displayed time-dependent inhibition towards human DPP III, characterized by the second-order rate constant of 6924+/-549 M(-1)min(-1) (K(i)=0.20 microM). The peptide substrate valorphin protected the enzyme from inactivation by 1'.
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Affiliation(s)
- Dejan Agić
- Department of Chemistry, Faculty of Agriculture, The Josip Juraj Strossmayer University, Trg Sv. Trojstva 3, P.O. Box 719, HR-31107 Osijek, Croatia
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