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Singh SK, Sasmal S, Kumar Y. Therapeutic Potential of HMF and Its Derivatives: a Computational Study. Appl Biochem Biotechnol 2024; 196:841-877. [PMID: 37223872 PMCID: PMC10206368 DOI: 10.1007/s12010-023-04547-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2023] [Indexed: 05/25/2023]
Abstract
Over the past century, chemicals and energy have increasingly been derived from non-renewable resources. The growing demand for essential chemicals and shrinking inventory make reliable, sustainable sources essential. Carbohydrates offer by far the greatest carbon supply. Furan compounds, a particular family of dehydration products, are believed to offer high chemical potential. Here, we analyze 5-HMF (5, hydroxymethylfurfural) and some of its derivatives in particular, a furan-type platform chemical. To analyze the therapeutic potential of HMF and its derivatives, this study utilized cutting-edge technologies such as computer-aided drug design, virtual screening, molecular docking, and molecular dynamic simulation. We conducted 189 docking simulations and examined some of the most promising dock poses using the molecular dynamic simulator. As for the receptors for our compounds, the leading candidates are human acetylcholinesterase, beta-lactamases, P. aeruginosa LasR, and S. aureus tyrosyl-tRNA synthetases. Out of all derivatives considered in this study, 2,5-furandicarboxylic acid (FCA) performed best.
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Affiliation(s)
- Shashank Kumar Singh
- Department of Biological Sciences and Engineering (BSE), Netaji Subhas University of Technology, Dwarka Sector-3, New Delhi, 110078, India
| | - Soumya Sasmal
- Department of Biotechnology, Visva Bharati, Santiniketan, West Bengal, 731235, India
| | - Yatender Kumar
- Department of Biological Sciences and Engineering (BSE), Netaji Subhas University of Technology, Dwarka Sector-3, New Delhi, 110078, India.
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2
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Kosińska A, Virieux D, Pirat JL, Czarnecka K, Girek M, Szymański P, Wojtulewski S, Vasudevan S, Chworos A, Rudolf B. Synthesis and Biological Studies of Novel Aminophosphonates and Their Metal Carbonyl Complexes (Fe, Ru). Int J Mol Sci 2022; 23:ijms23158091. [PMID: 35897660 PMCID: PMC9330042 DOI: 10.3390/ijms23158091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 02/01/2023] Open
Abstract
The quest to find new inhibitors of biologically relevant targets is considered an important strategy to introduce new drug candidates for the treatment of neurodegenerative diseases. A series of (aminomethyl)benzylphosphonates 8a–c and their metallocarbonyl iron 9a–c and ruthenium 10a–c complexes were designed, synthesized, and evaluated for their inhibitory potentials against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) by determination of IC50. Metallocarbonyl derivatives, in general, did not show significant inhibition activity against these enzymes, the most potent inhibitor was the (aminomethyl)benzylphosphonate 8a (IC50 = 1.215 µM against AChE). Molecular docking analysis of AChE and (aminomethyl)benzylphosphonates 8a–c showed the strongest interactions of 8a and AChE compared to isomers 8b and 8c. Cytotoxicity studies of synthesized compounds towards the V79 cell line were also performed and discussed.
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Affiliation(s)
- Aneta Kosińska
- Department of Organic Chemistry, Faculty of Chemistry, University of Lodz, Tamka 12, 91-403 Lodz, Poland
- ICGM, Univ. Montpellier, CNRS, ENSCM, 34090 Montpellier, France; (D.V.); (J.-L.P.)
- Correspondence: (A.K.); (B.R.)
| | - David Virieux
- ICGM, Univ. Montpellier, CNRS, ENSCM, 34090 Montpellier, France; (D.V.); (J.-L.P.)
| | - Jean-Luc Pirat
- ICGM, Univ. Montpellier, CNRS, ENSCM, 34090 Montpellier, France; (D.V.); (J.-L.P.)
| | - Kamila Czarnecka
- Department of Pharmaceutical Chemistry, Drug Analyses and Radiopharmacy, Faculty of Pharmacy, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland; (K.C.); (P.S.)
| | - Małgorzata Girek
- Animal House, Faculty of Pharmacy, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland;
| | - Paweł Szymański
- Department of Pharmaceutical Chemistry, Drug Analyses and Radiopharmacy, Faculty of Pharmacy, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland; (K.C.); (P.S.)
- Department of Radiobiology and Radiation Protection, Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-163 Warsaw, Poland
| | - Sławomir Wojtulewski
- Department of Structural Chemistry, Faculty of Chemistry, University of Bialystok, Ciołkowskiego 1K, 15-245 Bialystok, Poland;
| | - Saranya Vasudevan
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland; (S.V.); (A.C.)
| | - Arkadiusz Chworos
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland; (S.V.); (A.C.)
| | - Bogna Rudolf
- Department of Organic Chemistry, Faculty of Chemistry, University of Lodz, Tamka 12, 91-403 Lodz, Poland
- Correspondence: (A.K.); (B.R.)
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Pereira GRC, Gonçalves LM, Abrahim-Vieira BDA, De Mesquita JF. In silico analyses of acetylcholinesterase (AChE) and its genetic variants in interaction with the anti-Alzheimer drug Rivastigmine. J Cell Biochem 2022; 123:1259-1277. [PMID: 35644025 DOI: 10.1002/jcb.30277] [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: 04/13/2022] [Accepted: 05/14/2022] [Indexed: 11/08/2022]
Abstract
Alzheimer's disease (AD) is the leading cause of dementia worldwide. Despite causing great social and economic impact, there is currently no cure for AD. The most effective therapy to manage AD symptoms is based on acetylcholinesterase inhibitors (AChEi), from which rivastigmine presented numerous benefits. However, mutations in AChE, which affect approximately 5% of the population, can modify protein structure and function, changing the individual response to Alzheimer's treatment. In this study, we performed computer simulations of AChE wild type and variants R34Q, P135A, V333E, and H353N, identified by one or more genome-wide association studies, to evaluate their effects on protein structure and interaction with rivastigmine. The functional effects of AChE variants were predicted using eight machine learning algorithms, while the evolutionary conservation of AChE residues was analyzed using the ConSurf server. Autodock4.2.6 was used to predict the binding modes for the hAChE-rivastigmine complex, which is still unknown. Molecular dynamics (MD) simulations were performed in triplicates for the AChE wild type and mutants using the GROMACS packages. Among the analyzed variants, P135A was classified as deleterious by all the functional prediction algorithms, in addition to occurring at highly conserved positions, which may have harmful consequences on protein function. The molecular docking results suggested that rivastigmine interacts with hAChE at the upper active-site gorge, which was further confirmed by MD simulations. Our MD findings also suggested that the complex hAChE-rivastigmine remains stable over time. The essential dynamics revealed flexibility alterations at the active-site gorge upon mutations P135A, V333E, and H353N, which may lead to strong and nonintuitive consequences to hAChE binding. Nonetheless, similar binding affinities were registered in the MMPBSA analysis for the hAChE wild type and variants when complexed to rivastigmine. Finally, our findings indicated that the rivastigmine binding to hAChE is an energetically favorable process mainly driven by negatively charged amino acids.
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Affiliation(s)
| | - Lucas Machado Gonçalves
- Bioinformatics and Computational Biology Laboratory, Federal University of the State of Rio de Janeiro-UNIRIO, Rio de Janeiro, Brazil
| | | | - Joelma Freire De Mesquita
- Bioinformatics and Computational Biology Laboratory, Federal University of the State of Rio de Janeiro-UNIRIO, Rio de Janeiro, Brazil
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Uthra C, Reshi MS, Jaswal A, Yadav D, Shrivastava S, Sinha N, Shukla S. Protective efficacy of rutin against acrylamide-induced oxidative stress, biochemical alterations and histopathological lesions in rats. Toxicol Res (Camb) 2022; 11:215-225. [PMID: 35237426 PMCID: PMC8882811 DOI: 10.1093/toxres/tfab125] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/11/2021] [Accepted: 12/12/2021] [Indexed: 01/28/2023] Open
Abstract
Acrylamide is a well-known neurotoxicant and carcinogen. Apart from industrial exposure, acrylamide is also found in different food products. The present study deals with in vivo experiment to test the protective effect of rutin against acrylamide induced toxicity in rats. The study was carried out on female rats with exposure of acrylamide at the dose of 38.27 mg/kg body weight, orally for 10 days followed by the therapy of rutin (05, 10, 20 and 40 mg/kg orally), for three consecutive days. All animals were sacrificed after 24 h of last treatment and various biochemical parameters in blood and tissue were investigated. Histopathology of liver, kidney and brain was also done. On administration of acrylamide for 10 days, neurotoxicity was observed in terms of decreased acetylcholinesterase activity and oxidative stress was observed in terms of increased lipid peroxidation, declined level of reduced glutathione, antioxidant enzymes (superoxide dismutase and catalase) in liver, kidney and brain. Acrylamide exposure increased the activities of serum transaminases, lipid profile, bilirubin, urea, uric acid and creatinine in serum indicating damage. Our experimental results conclude that rutin showed remarkable protection against oxidative DNA damage induced by acrylamide, which may be due to its antioxidant potential.
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Affiliation(s)
- Chhavi Uthra
- Correspondence address. Reproductive Biology and Toxicology Laboratory, UNESCO-Trace Element Satellite Centre, School of Studies in Zoology, Jiwaji University, Gwalior, Madhya Pradesh, 474011, India. Tel: 9755952336 (M); E-mail:
| | - Mohd Salim Reshi
- Toxicology and Pharmacology Lab, Department of Zoology, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, Jammu & Kashmir, 185234, India
| | - Amita Jaswal
- Reproductive Biology and Toxicology Laboratory, UNESCO-Trace Element Satellite Centre, School of Studies in Zoology, Jiwaji University, Gwalior, Madhya Pradesh, 474011, India
| | - Deepa Yadav
- Reproductive Biology and Toxicology Laboratory, UNESCO-Trace Element Satellite Centre, School of Studies in Zoology, Jiwaji University, Gwalior, Madhya Pradesh, 474011, India
| | - Sadhana Shrivastava
- Reproductive Biology and Toxicology Laboratory, UNESCO-Trace Element Satellite Centre, School of Studies in Zoology, Jiwaji University, Gwalior, Madhya Pradesh, 474011, India
| | - Neelu Sinha
- Reproductive Biology and Toxicology Laboratory, UNESCO-Trace Element Satellite Centre, School of Studies in Zoology, Jiwaji University, Gwalior, Madhya Pradesh, 474011, India
| | - Sangeeta Shukla
- Reproductive Biology and Toxicology Laboratory, UNESCO-Trace Element Satellite Centre, School of Studies in Zoology, Jiwaji University, Gwalior, Madhya Pradesh, 474011, India
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Fantasia RJ, Nourmahnad A, Halpin E, Forman SA. Substituted Cysteine Modification and Protection with n-Alkyl- Methanethiosulfonate Reagents Yields a Precise Estimate of the Distance between Etomidate and a Residue in Activated GABA Type A Receptors. Mol Pharmacol 2021; 99:426-434. [PMID: 33766924 DOI: 10.1124/molpharm.120.000224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/10/2021] [Indexed: 11/22/2022] Open
Abstract
The anesthetic etomidate modulates synaptic α1β2/3γ2 GABAA receptors via binding sites located in transmembrane β+/α- interfaces. Various approaches indicate that etomidate binds near β2/3M286 side chains, including recent cryogenic electron microscopy images in α1β2γ2L receptors under nonphysiologic conditions with ∼3.5-Å resolution. We hypothesized that substituted cysteine modification and protection experiments using variably sized n-alkyl-methanethiosulfonate (MTS) reagents could precisely estimate the distance between bound etomidate and β3M286 side chains in activated functional receptors. Using voltage-clamp electrophysiology in Xenopus oocytes expressing α1β3M286Cγ2L GABAA receptors, we measured functional changes after exposing GABA-activated receptors to n-alkyl-MTS reagents, from methyl-MTS to n-decyl-MTS. Based on previous studies using a large sulfhydryl reagent, we anticipated that cysteine modifications large enough to overlap etomidate sites would cause persistently increased GABA sensitivity and decreased etomidate modulation and that etomidate would hinder these modifications, reducing effects. Based on altered GABA or etomidate sensitivity, ethyl-MTS and larger n-alkyl-MTS reagents modified GABA-activated α1β3M286Cγ2L GABAA receptors. Receptor modification by n-propyl-MTS or larger reagents caused persistently increased GABA sensitivity and decreased etomidate modulation. Receptor-bound etomidate blocked β3M286C modification by n-propyl-MTS, n-butyl-MTS, and n-hexyl-MTS. In contrast, GABA sensitivity was unaltered by receptor exposure to methyl-MTS or ethyl-MTS, and ethyl-MTS modification uniquely increased etomidate modulation. These results reveal a "cut-on" between ethyl-MTS and n-propyl-MTS, from which we infer that -S-(n-propyl) is the smallest β3M286C appendage that overlaps with etomidate sites. Molecular models of the native methionine and -S-ethyl and -S-(n-propyl) modified cysteines suggest that etomidate is located between 1.7 and 3.0 Å from the β3M286 side chain. SIGNIFICANCE STATEMENT: Precise spatial relationships between drugs and their receptor sites are essential for mechanistic understanding and drug development. This study combined electrophysiology, a cysteine substitution, and n-alkyl-methanethiosulfonate modifiers, creating a precise molecular ruler to estimate the distance between a α1β3γ2L GABA type A receptor residue and etomidate bound in the transmembrane β+/α- interface.
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Affiliation(s)
- Ryan J Fantasia
- Beecher-Mallinckrodt Laboratories, Department of Anesthesia Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Anahita Nourmahnad
- Beecher-Mallinckrodt Laboratories, Department of Anesthesia Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Elizabeth Halpin
- Beecher-Mallinckrodt Laboratories, Department of Anesthesia Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Stuart A Forman
- Beecher-Mallinckrodt Laboratories, Department of Anesthesia Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
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The inefficacy of donepezil on glycated-AChE inhibition: Binding affinity, complex stability and mechanism. Int J Biol Macromol 2020; 160:35-46. [PMID: 32454110 DOI: 10.1016/j.ijbiomac.2020.05.177] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 05/17/2020] [Accepted: 05/21/2020] [Indexed: 12/14/2022]
Abstract
Donepezil (DPZ) is a well-known drug for Alzheimer's disease that inhibits acetylcholinesterase activity (AChE). In the present study, the inhibitory effect of DPZ on non-enzymatic glycated-AChE (GLY-AChE) was studied by different experimental and simulation techniques. The initial investigation revealed that glycation process could reduce AChE activity approximately 60% in the pure enzyme and 38% in the extracted crude AChE from neural cells cultured in the presence of high glucose (HG) concentration. It is suggested that glycation of lysine residues on the structure of AChE could change the conformation of the active site (Trp-86 and His-447) in a way that the orientation of acetylcholine interrupted. The further studies indicated that DPZ is although a strong inhibitor for the native enzyme, it is not able to affect the GLY-AChE activity. The KD values of AChE-DPZ and GLY-AChE-DPZ complexes were estimated to be 1.88 × 10-9 and 2.10 × 10-6, respectively. The stability assessment showed that AChE-DPZ complex is more stable than the glycated complex. Our results indicate that, glycation process could impact on the conformation of the residues involved in the DPZ binding cavity on α-helix domain. Therefore, DPZ is not able to bind its specific cavity to induce its inhibitory effects on GLY-AChE.
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Zambrano P, Suwalsky M, Jemiola-Rzeminska M, Strzalka K, Aguilar LF. An in vitro study on the interaction of the anti-Alzheimer drug rivastigmine with human erythrocytes. Chem Biol Interact 2020; 319:109019. [PMID: 32092302 DOI: 10.1016/j.cbi.2020.109019] [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: 12/22/2019] [Revised: 02/13/2020] [Accepted: 02/18/2020] [Indexed: 10/25/2022]
Abstract
The inhibition of the enzyme acetylcholinesterase (AChE) is a frequently used therapeutic option to treat Alzheimer's disease (AD). By decreasing the levels of acetylcholine degradation in the synaptic space, some cognitive functions of patients suffering from this disease are significantly improved. Rivastigmine is one of the most widely used AChE inhibitors. The objective of this work was to determine the effects of this drug on human erythrocytes, which have a type of AChE in the cell membrane. To that end, human erythrocytes and molecular models of its membrane constituted by dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE) were used. They correspond to classes of phospholipids present in the outer and inner monolayers of the human erythrocyte membrane, respectively. The experimental results obtained by X-ray diffraction and differential scanning calorimetry (DSC) indicated that rivastigmine molecules were able to interact with both phospholipids. Fluorescence spectroscopy results showed that rivastigmine produce a slight change in the acyl chain packing order and a weak displacement of the water molecules of the hydrophobic-hydrophilic membrane interface. On the other hand, observations by scanning electron microscopy (SEM) showed that the drug changed the normal biconcave shape of erythrocytes in stomatocytes (cup-shaped cells) and echinocytes (speculated shaped).
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Affiliation(s)
- Pablo Zambrano
- Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile.
| | - Mario Suwalsky
- Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile
| | - Malgorzata Jemiola-Rzeminska
- Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland; Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Kazimierz Strzalka
- Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland; Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Luis F Aguilar
- Instituto de Química, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
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Abdul Manap AS, Wei Tan AC, Leong WH, Yin Chia AY, Vijayabalan S, Arya A, Wong EH, Rizwan F, Bindal U, Koshy S, Madhavan P. Synergistic Effects of Curcumin and Piperine as Potent Acetylcholine and Amyloidogenic Inhibitors With Significant Neuroprotective Activity in SH-SY5Y Cells via Computational Molecular Modeling and in vitro Assay. Front Aging Neurosci 2019; 11:206. [PMID: 31507403 PMCID: PMC6718453 DOI: 10.3389/fnagi.2019.00206] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/22/2019] [Indexed: 12/21/2022] Open
Abstract
Hallmarks of Alzheimer's disease (AD) pathology include acetylcholine (ACh) deficiency and plaque deposition. Emerging studies suggest that acetylcholinesterase (AChE) may interact with amyloid β (Aβ) to promote aggregation of insoluble Aβ plaques in brains of patients. Current therapeutic options available for AD patients, such as AChE inhibitors, provide only symptomatic relief. In this study, we screened four natural compounds believed to harbor cognitive benefits-curcumin, piperine, bacoside A, and chebulinic acid. In the first section, preliminary screening through computational molecular docking simulations gauged the suitability of the compounds as novel AChE inhibitors. From here, only compounds that met the in silico selection criteria were selected for the second section through in vitro investigations, including AChE enzyme inhibition assay, 3-(4,5-dimenthylthiazol-2-yl)-2,5-dimethyltetrazolium bromide (MTT) assay, Thioflavin T (ThT) assay, and biochemical analysis via a neuronal cell line model. Of the four compounds screened, only curcumin (-9.6 kcal/mol) and piperine (-10.5 kcal/mol) showed favorable binding affinities and interactions towards AChE and were hence selected. In vitro AChE inhibition demonstrated that combination of curcumin and piperine showed greater AChE inhibition with an IC50 of 62.81 ± 0.01 μg/ml as compared to individual compounds, i.e., IC50 of curcumin at 134.5 ± 0.06 μg/ml and IC50 of piperine at 76.6 ± 0.08 μg/ml. In the SH-SY5Y cell model, this combination preserved cell viability up to 85%, indicating that the compounds protect against Aβ-induced neuronal damage (p < 0.01). Interestingly, our results also showed that curcumin and piperine achieved a synergistic effect at 35 μM with an synergism quotient (SQ) value of 1.824. Synergistic behavior indicates that the combination of these two compounds at lower concentrations may provide a better outcome than singularly used for Aβ proteins. Combined curcumin and piperine managed to inhibit aggregation (reduced ThT intensity at 0.432 a.u.; p < 0.01) as well as disaggregation (reduced ThT intensity at 0.532 a.u.; p < 0.01) of fibrillar Aβ42. Furthermore, combined curcumin and piperine reversed the Aβ-induced up-regulation of neuronal oxidative stress (p < 0.01). In conclusion, curcumin and piperine demonstrated promising neuroprotective effects, whereas bacoside A and chebulinic acid may not be suitable lead compounds. These results are hoped to advance the field of natural products research as potentially therapeutic and curative AD agents.
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Affiliation(s)
- Aimi Syamima Abdul Manap
- School of Biosciences, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Amelia Cheng Wei Tan
- School of Biosciences, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Weng Hhin Leong
- School of Biosciences, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Adeline Yoke Yin Chia
- School of Biosciences, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Shantini Vijayabalan
- School of Pharmacy, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Aditya Arya
- School of Medicine, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Eng Hwa Wong
- School of Medicine, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Farzana Rizwan
- School of Medicine, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Umesh Bindal
- School of Medicine, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Shajan Koshy
- School of Medicine, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
| | - Priya Madhavan
- School of Medicine, Faculty of Health and Sciences, Taylor’s University, Subang Jaya, Malaysia
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Carlier PR, Bloomquist JR, Totrov M, Li J. Discovery of Species-selective and Resistance-breaking Anticholinesterase Insecticides for the Malaria Mosquito. Curr Med Chem 2017; 24:2946-2958. [PMID: 28176636 DOI: 10.2174/0929867324666170206130024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 12/20/2016] [Accepted: 01/20/2017] [Indexed: 11/22/2022]
Abstract
Great reductions in malaria mortality have been accomplished in the last 15 years, in part due to the widespread roll-out of insecticide-treated bednets across sub-Saharan Africa. To date, these nets only employ pyrethroids, insecticides that target the voltage-gated sodium ion channel of the malaria vector, Anopheles gambiae. Due to the growing emergence of An. gambiae strains that are resistant to pyrethroids, there is an urgent need to develop new public health insecticides that engage a different target and possess low mammalian toxicity. In this review, we will describe efforts to develop highly species-specific and resistance-breaking inhibitors of An. gambiae acetylcholinesterase (AgAChE). These efforts have been greatly aided by advances in knowledge of the structure of the enzyme, and two major inhibitor design strategies have been explored. Since AgAChE possesses an unpaired Cys residue not present in mammalian AChE, a logical strategy to achieve selective inhibition involves design of compounds that could ligate that Cys. A second strategy involves the design of new molecules to target the catalytic serine of the enzyme. Here the challenge is not only to achieve high inhibition selectivity vs human AChE, but also to demonstrate toxicity to An. gambiae that carry the G119S resistance mutation of AgAChE. The advances made and challenges remaining will be presented. This review is part of the special issue "Insecticide Mode of Action: From Insect to Mammalian Toxicity".
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Affiliation(s)
- Paul R Carlier
- Department of Chemistry, Virginia Tech, Blacksburg, VA 24061. United States
| | - Jeffrey R Bloomquist
- Department of Entomology and Nematology and Emerging Pathogens Institute, University of Florida, 2055 Mowry Road, P.O. Box 100009, Gainesville, FL 32610-00009. United States
| | - Max Totrov
- Molsoft LLC, 11199 Sorrento Valley Road, San Diego, CA 92121. United States
| | - Jianyong Li
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061. United States
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Hsu HH, Hsu YC, Chang LJ, Yang JM. An integrated approach with new strategies for QSAR models and lead optimization. BMC Genomics 2017; 18:104. [PMID: 28361681 PMCID: PMC5374651 DOI: 10.1186/s12864-017-3503-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Computational drug design approaches are important for shortening the time and reducing the cost for drug discovery and development. Among these methods, molecular docking and quantitative structure activity relationship (QSAR) play key roles for lead discovery and optimization. Here, we propose an integrated approach with core strategies to identify the protein-ligand hot spots for QSAR models and lead optimization. These core strategies are: 1) to generate both residue-based and atom-based interactions as the features; 2) to identify compound common and specific skeletons; and 3) to infer consensus features for QSAR models. Results We evaluated our methods and new strategies on building QSAR models of human acetylcholinesterase (huAChE). The leave-one-out cross validation values q2 and r2 of our huAChE QSAR model are 0.82 and 0.78, respectively. The experimental results show that the selected features (resides/atoms) are important for enzymatic functions and stabling the protein structure by forming key interactions (e.g., stack forces and hydrogen bonds) between huAChE and its inhibitors. Finally, we applied our methods to arthrobacter globiformis histamine oxidase (AGHO) which is correlated to heart failure and diabetic. Conclusions Based on our AGHO QSAR model, we identified a new substrate verified by bioassay experiments for AGHO. These results show that our methods and new strategies can yield stable and high accuracy QSAR models. We believe that our methods and strategies are useful for discovering new leads and guiding lead optimization in drug discovery. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3503-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hui-Hui Hsu
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Yen-Chao Hsu
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Li-Jen Chang
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Jinn-Moon Yang
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 300, Taiwan. .,Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 300, Taiwan.
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11
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Papaleo E, Saladino G, Lambrughi M, Lindorff-Larsen K, Gervasio FL, Nussinov R. The Role of Protein Loops and Linkers in Conformational Dynamics and Allostery. Chem Rev 2016; 116:6391-423. [DOI: 10.1021/acs.chemrev.5b00623] [Citation(s) in RCA: 239] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Elena Papaleo
- Computational
Biology Laboratory, Unit of Statistics, Bioinformatics and Registry, Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark
- Structural
Biology and NMR Laboratory, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Giorgio Saladino
- Department
of Chemistry, University College London, London WC1E 6BT, United Kingdom
| | - Matteo Lambrughi
- Department
of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza
della Scienza 2, 20126 Milan, Italy
| | - Kresten Lindorff-Larsen
- Structural
Biology and NMR Laboratory, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | - Ruth Nussinov
- Cancer
and Inflammation Program, Leidos Biomedical Research, Inc., Frederick
National Laboratory for Cancer Research, National Cancer Institute Frederick, Frederick, Maryland 21702, United States
- Sackler Institute
of Molecular Medicine, Department of Human Genetics and Molecular
Medicine Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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12
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Karasova JZ, Hroch M, Musilek K, Kuca K. Small Quaternary Inhibitors K298 and K524: Cholinesterases Inhibition, Absorption, Brain Distribution, and Toxicity. Neurotox Res 2015; 29:267-74. [DOI: 10.1007/s12640-015-9582-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/06/2015] [Accepted: 11/24/2015] [Indexed: 10/22/2022]
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13
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Reilly PJ, Rovira C. Computational Studies of Glycoside, Carboxylic Ester, and Thioester Hydrolase Mechanisms: A Review. Ind Eng Chem Res 2015. [DOI: 10.1021/acs.iecr.5b01312] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter J. Reilly
- Department
of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011-2230, United States
| | - Carme Rovira
- Departament de Química Orgànica
and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain
- Institució
Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
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14
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Bourne Y, Renault L, Marchot P. Crystal structure of snake venom acetylcholinesterase in complex with inhibitory antibody fragment Fab410 bound at the peripheral site: evidence for open and closed states of a back door channel. J Biol Chem 2014; 290:1522-35. [PMID: 25411244 DOI: 10.1074/jbc.m114.603902] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The acetylcholinesterase found in the venom of Bungarus fasciatus (BfAChE) is produced as a soluble, non-amphiphilic monomer with a canonical catalytic domain but a distinct C terminus compared with the other vertebrate enzymes. Moreover, the peripheral anionic site of BfAChE, a surface site located at the active site gorge entrance, bears two substitutions altering sensitivity to cationic inhibitors. Antibody Elec410, generated against Electrophorus electricus acetylcholinesterase (EeAChE), inhibits EeAChE and BfAChE by binding to their peripheral sites. However, both complexes retain significant residual catalytic activity, suggesting incomplete gorge occlusion by bound antibody and/or high frequency back door opening. To explore a novel acetylcholinesterase species, ascertain the molecular bases of inhibition by Elec410, and document the determinants and mechanisms for back door opening, we solved a 2.7-Å resolution crystal structure of natural BfAChE in complex with antibody fragment Fab410. Crystalline BfAChE forms the canonical dimer found in all acetylcholinesterase structures. Equally represented open and closed states of a back door channel, associated with alternate positions of a tyrosine phenol ring at the active site base, coexist in each subunit. At the BfAChE molecular surface, Fab410 is seated on the long Ω-loop between two N-glycan chains and partially occludes the gorge entrance, a position that fully reflects the available mutagenesis and biochemical data. Experimentally based flexible molecular docking supports a similar Fab410 binding mode onto the EeAChE antigen. These data document the molecular and dynamic peculiarities of BfAChE with high frequency back door opening, and the mode of action of Elec410 as one of the largest peptidic inhibitors targeting the acetylcholinesterase peripheral site.
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Affiliation(s)
- Yves Bourne
- From Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques, campus Luminy, 13228 Marseille cedex 09, France, CNRS, Architecture et Fonction des Macromolécules Biologiques, campus Luminy, 13228 Marseille cedex 09, France, and
| | - Ludovic Renault
- CNRS/Aix-Marseille Université, Ingénierie des Protéines, Faculté de Médecine-Secteur Nord, 13344 Marseille cedex 15, France
| | - Pascale Marchot
- From Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques, campus Luminy, 13228 Marseille cedex 09, France, CNRS, Architecture et Fonction des Macromolécules Biologiques, campus Luminy, 13228 Marseille cedex 09, France, and CNRS/Aix-Marseille Université, Ingénierie des Protéines, Faculté de Médecine-Secteur Nord, 13344 Marseille cedex 15, France
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15
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Bourne Y, Renault L, Essono S, Mondielli G, Lamourette P, Boquet D, Grassi J, Marchot P. Molecular characterization of monoclonal antibodies that inhibit acetylcholinesterase by targeting the peripheral site and backdoor region. PLoS One 2013; 8:e77226. [PMID: 24146971 PMCID: PMC3795623 DOI: 10.1371/journal.pone.0077226] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 09/02/2013] [Indexed: 11/19/2022] Open
Abstract
The inhibition properties and target sites of monoclonal antibodies (mAbs) Elec403, Elec408 and Elec410, generated against Electrophorus electricus acetylcholinesterase (AChE), have been defined previously using biochemical and mutagenesis approaches. Elec403 and Elec410, which bind competitively with each other and with the peptidic toxin inhibitor fasciculin, are directed toward distinctive albeit overlapping epitopes located at the AChE peripheral anionic site, which surrounds the entrance of the active site gorge. Elec408, which is not competitive with the other two mAbs nor fasciculin, targets a second epitope located in the backdoor region, distant from the gorge entrance. To characterize the molecular determinants dictating their binding site specificity, we cloned and sequenced the mAbs; generated antigen-binding fragments (Fab) retaining the parental inhibition properties; and explored their structure-function relationships using complementary x-ray crystallography, homology modeling and flexible docking approaches. Hypermutation of one Elec403 complementarity-determining region suggests occurrence of antigen-driven selection towards recognition of the AChE peripheral site. Comparative analysis of the 1.9Å-resolution structure of Fab408 and of theoretical models of its Fab403 and Fab410 congeners evidences distinctive surface topographies and anisotropic repartitions of charges, consistent with their respective target sites and inhibition properties. Finally, a validated, data-driven docking model of the Fab403-AChE complex suggests a mode of binding at the PAS that fully correlates with the functional data. This comprehensive study documents the molecular peculiarities of Fab403 and Fab410, as the largest peptidic inhibitors directed towards the peripheral site, and those of Fab408, as the first inhibitor directed toward the backdoor region of an AChE and a unique template for the design of new, specific modulators of AChE catalysis.
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Affiliation(s)
- Yves Bourne
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS/Aix-Marseille Université, Campus Luminy, Marseille, France
| | - Ludovic Renault
- Ingénierie des Protéines, CNRS/Aix-Marseille Université, Faculté de Médecine - Secteur Nord, Marseille, France
| | - Sosthène Essono
- CEA, iBiTecS, Service de Pharmacologie et Immunologie (SPI), Laboratoire d’Etude et de Recherche en Immunoanalyse (LERI), Gif-sur-Yvette, France
| | - Grégoire Mondielli
- Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille (CRN2M), CNRS/Aix-Marseille Université, Faculté de Médecine - Secteur Nord, Marseille, France
| | - Patricia Lamourette
- CEA, iBiTecS, Service de Pharmacologie et Immunologie (SPI), Laboratoire d’Etude et de Recherche en Immunoanalyse (LERI), Gif-sur-Yvette, France
| | - Didier Boquet
- CEA, iBiTecS, Service de Pharmacologie et Immunologie (SPI), Laboratoire d’Ingénierie des Anticorps pour la Santé (LIAS), Gif-sur-Yvette, France
| | - Jacques Grassi
- CEA, iBiTecS, Service de Pharmacologie et Immunologie (SPI), Laboratoire d’Etude et de Recherche en Immunoanalyse (LERI), Gif-sur-Yvette, France
| | - Pascale Marchot
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS/Aix-Marseille Université, Campus Luminy, Marseille, France
- Ingénierie des Protéines, CNRS/Aix-Marseille Université, Faculté de Médecine - Secteur Nord, Marseille, France
- Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille (CRN2M), CNRS/Aix-Marseille Université, Faculté de Médecine - Secteur Nord, Marseille, France
- * E-mail:
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16
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Affiliation(s)
- Shengwen Shen
- Department
of Laboratory Medicine
and Pathology, 10-102 Clinical Sciences Building, University
of Alberta, Edmonton, Alberta, Canada, T6G 2G3
| | - Xing-Fang Li
- Department
of Laboratory Medicine
and Pathology, 10-102 Clinical Sciences Building, University
of Alberta, Edmonton, Alberta, Canada, T6G 2G3
| | - William R. Cullen
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver,
British Columbia, Canada, V6T 1Z1
| | - Michael Weinfeld
- Department of Oncology, Cross
Cancer Institute, University of Alberta, 11560 University Avenue, Edmonton, Alberta, Canada, T6G 1Z2
| | - X. Chris Le
- Department
of Laboratory Medicine
and Pathology, 10-102 Clinical Sciences Building, University
of Alberta, Edmonton, Alberta, Canada, T6G 2G3
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17
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Orhan IE. Nature: a substantial source of auspicious substances with acetylcholinesterase inhibitory action. Curr Neuropharmacol 2013; 11:379-87. [PMID: 24381529 PMCID: PMC3744902 DOI: 10.2174/1570159x11311040003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 02/05/2013] [Accepted: 02/05/2013] [Indexed: 12/26/2022] Open
Abstract
Acetylcholinesterase (AChE) (EC 3.1.1.7) is an important enzyme that breaks down of acetylcholine in synaptic cleft in neuronal junctions. Inhibition of AChE is associated with treatment of several diseases such as Alzheimer's disease (AD), myasthenia gravis, and glaucoma as well as the mechanisms of insecticide and anthelmintic drugs. Several AChE inhibitors are available in clinical use currently for the treatment of AD; however, none of them has ability, yet, to seize progress of the disease. Consequently, an extensive research has been going on finding new AChE inhibitors. In this sense, natural inhibitors have gained great attention due to their encouraging effects toward AChE. In this review, promising candidate molecules with marked AChE inhibition from both plant and animal sources will be underlined.
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Affiliation(s)
- Ilkay Erdogan Orhan
- Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey
- Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmacy, Eastern Mediterranean University, Gazimagosa, The Northern Cyprus via Turkey
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18
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Jiang S, Wang X, Xi R, Zhang Y. Research on the regulation of the spatial structure of acetylcholinesterase tetramer with high efficiency by AFM. Int J Nanomedicine 2013; 8:1095-102. [PMID: 23515568 PMCID: PMC3600998 DOI: 10.2147/ijn.s41591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Atomic force microscopy (AFM) was applied for obtaining structural information about acetylcholinesterase (AChE) tetramer (AChE G4) before and after reaction with S-acetylcholine iodide (S-ACh), in the presence or absence of propidium iodide (PI), an inhibitor for peripheral anionic sites (PAS). An iced-bath ultrasound was used to prepare the phospholipid membrane. Ves-fusion technique was applied for incorporating AChE G4 in a lipid layer on mica. Before reaction with substrates, the single AChE G4 particle was ellipsoid in shape with a clear border. It had a smooth surface with a central projection. The four subunits of a single enzyme particle were arranged tightly (no separated subunits being found, with an average size of 89 ± 7 nm in length, 68 ± 9 nm in width, and 6 ± 3 nm in height). After reaction with S-ACh in the absence of PI, the loose arrangement of subunits of AChE G4 was seen, with an average size of 104 ± 7 nm in length, 91 ± 5 nm in width, and 8 ± 2 nm in height. Also there was free-flowing space amongst the four subunits of the AChE G4. This was consistent with the results of the ×-ray diffraction crystallography and molecular dynamics studies. The apparent free space was the central path of AChE G4, changing from small to big, to small, to lateral door appearance, with an average size of 60 ± 5 nm in length and 51 ± 9 nm in width. The size of lateral door was 52 ± 5 nm in width and 32 ± 3 nm in depth on average. In the presence of PI, S-ACh could not cause topological structure changes of AChE G4. AFM verified that the central path might govern the turnover of the enzyme morphologically, and the interactions between PI and S-ACh might gate the creation of a central path and the opening of ACG in monomer; and the combination of S-ACh with peripheral anionic sites is conducive to the opening of ACG while PI can inhibit this action. Resolution at the inframolecular level is favorable in providing substantial information on how the spatial structure is adapted to the high efficiency of AChE molecules.
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Affiliation(s)
- Shuang Jiang
- 210th Hospital of People Liberation Army, Dalian, People's Republic of China
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19
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Pang YP, Brimijoin S, Ragsdale DW, Zhu KY, Suranyi R. Novel and viable acetylcholinesterase target site for developing effective and environmentally safe insecticides. Curr Drug Targets 2012; 13:471-82. [PMID: 22280344 PMCID: PMC3343382 DOI: 10.2174/138945012799499703] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 12/01/2011] [Accepted: 12/09/2011] [Indexed: 12/01/2022]
Abstract
Insect pests are responsible for human suffering and financial losses worldwide. New and environmentally safe insecticides are urgently needed to cope with these serious problems. Resistance to current insecticides has resulted in a resurgence of insect pests, and growing concerns about insecticide toxicity to humans discourage the use of insecticides for pest control. The small market for insecticides has hampered insecticide development; however, advances in genomics and structural genomics offer new opportunities to develop insecticides that are less dependent on the insecticide market. This review summarizes the literature data that support the hypothesis that an insect-specific cysteine residue located at the opening of the acetylcholinesterase active site is a promising target site for developing new insecticides with reduced off-target toxicity and low propensity for insect resistance. These data are used to discuss the differences between targeting the insect-specific cysteine residue and targeting the ubiquitous catalytic serine residue of acetylcholinesterase from the perspective of reducing off-target toxicity and insect resistance. Also discussed is the prospect of developing cysteine-targeting anticholinesterases as effective and environmentally safe insecticides for control of disease vectors, crop damage, and residential insect pests within the financial confines of the present insecticide market.
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Affiliation(s)
- Yuan-Ping Pang
- Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA.
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20
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Lin MC, Lin GZ, Shen YF, Jian SY, Hsieh DK, Lin J, Lin G. Synthesis and evaluation of a new series of tri-, di-, and mono-N-alkylcarbamylphloroglucinols as bulky inhibitors of acetylcholinesterase. Chem Res Toxicol 2012; 25:1462-71. [PMID: 22690874 DOI: 10.1021/tx300119a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1,3,5-Tri-N-alkylcarbamylphloroglucinols (1-4) are synthesized as a new series of bulky inhibitors of acetylcholinesterase that may block the catalytic triad, the anionic substrate binding site, and the entrance of the enzyme simultaneously. Among three series of phloroglucinol-derived carbamates, tridentate inhibitors 1,3,5-tri-N-alkylcarbamylphloroglucinols (1-4), bidentate inhibitors 3,5-di-N-n-alkylcarbamyloxyphenols (5-8), and monodentate inhibitors 5-N-n-alkylcarbamyloxyresorcinols (9-12), tridentate inhibitors 1-4 are the most potent inhibitors of mouse acetylcholinesterase. When different n-alkylcarbamyl substituents in tridentate inhibitors 1-4 are compared, n-octylcarbamate 1 is the most potent inhibitor of the enzyme. All inhibitors 1-12 are characterized as the pseudo substrate inhibitors of acetylcholinesterase. Thus, tridentate inhibitors 1-4 are supposed to be hydrolyzed to bidentate inhibitors 5-8 after the enzyme catalysis. Subsequently, bidentate inhibitors 5-8 and monodentate inhibitors 9-12 are supposed to yield monodentate inhibitors 9-12 and phloroglucinol, respectively, after the enzyme catalysis. This means that tridentate inhibitors 1-4 may act as long period inhibitors of the enzyme. Therefore, inhibitors 1-4 may be considered as a new methodology to develop the long-acting drug for Alzheimer's disease. Automated dockings of inhibitor 1 into the X-ray crystal structure of acetylcholinesterase suggest that the most suitable configuration of inhibitor 1 to the enzyme binding is the (1,3,5)- (cis,trans,trans)-tricarbamate rotamer. The cis-carbamyl moiety of this rotamer does not bind into the acetyl group binding site of the enzyme but stretches out itself to the entrance. The other two trans-carbmayl moieties of this rotamer bulkily block the tryptophan 86 residue of the enzyme.
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Affiliation(s)
- Ming-Chen Lin
- Division of Internal Medicine, Chung Shan Medical University Hospital, School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan
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21
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Puiu M, Istrate O, Rotariu L, Bala C. Kinetic approach of aflatoxin B1–acetylcholinesterase interaction: A tool for developing surface plasmon resonance biosensors. Anal Biochem 2012; 421:587-94. [DOI: 10.1016/j.ab.2011.10.035] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 10/16/2011] [Accepted: 10/17/2011] [Indexed: 11/28/2022]
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22
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Structural approach to the aging of phosphylated cholinesterases. Chem Biol Interact 2010; 187:157-62. [DOI: 10.1016/j.cbi.2010.03.027] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2009] [Revised: 03/08/2010] [Accepted: 03/12/2010] [Indexed: 12/18/2022]
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23
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Butyrylcholinesterase for protection from organophosphorus poisons: catalytic complexities and hysteretic behavior. Arch Biochem Biophys 2009; 494:107-20. [PMID: 20004171 DOI: 10.1016/j.abb.2009.12.005] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 11/24/2009] [Accepted: 12/01/2009] [Indexed: 12/13/2022]
Abstract
Butyrylcholinesterase is a promiscuous enzyme that displays complex kinetic behavior. It is toxicologically important because it detoxifies organophosphorus poisons (OP) by making a covalent bond with the OP. The OP and the butyrylcholinesterase are both inactivated in the process. Inactivation of butyrylcholinesterase has no adverse effects. However, inactivation of acetylcholinesterase in nerve synapses can be lethal. OP-inhibited butyrylcholinesterase and acetylcholinesterase can be reactivated with oximes provided the OP has not aged. Strategies for preventing the toxicity of OP include (a) treatment with an OP scavenger, (b) reaction of non-aged enzyme with oximes, (c) reactivation of aged enzyme, (d) slowing down aging with peripheral site ligands, and (e) design of mutants that rapidly hydrolyze OP. Option (a) has progressed through phase I clinical trials with human butyrylcholinesterase. Option (b) is in routine clinical use. The others are at the basic research level. Butyrylcholinesterase displays complex kinetic behavior including activation by positively charged esters, ability to hydrolyze amides, and a lag time (hysteresis) preceding hydrolysis of benzoylcholine and N-methylindoxyl acetate. Mass spectrometry has identified new OP binding motifs on tyrosine and lysine in proteins that have no active site serine. It is proposed, but not yet proven, that low dose exposure involves OP modification of proteins that have no active site serine.
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24
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Methylacridinium and its Cholinergic Properties. Neurotox Res 2009; 16:372-7. [DOI: 10.1007/s12640-009-9071-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 03/06/2009] [Accepted: 06/10/2009] [Indexed: 10/20/2022]
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Pietsch M, Christian L, Inhester T, Petzold S, Gütschow M. Kinetics of inhibition of acetylcholinesterase in the presence of acetonitrile. FEBS J 2009; 276:2292-307. [PMID: 19292865 DOI: 10.1111/j.1742-4658.2009.06957.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The hydrolysis of acetylthiocholine by acetylcholinesterase from Electrophorus electricus was investigated in the presence of the inhibitors tacrine, gallamine and compound 1. The interaction of the enzyme with the substrate and the inhibitors was characterized by the parameters K(I), alpha', b or beta, K(m) and V(max), which were determined directly and simultaneously from nonlinear Michaelis-Menten plots. Tacrine was shown to act as a mixed-type inhibitor with a strong noncompetitive component (alpha' approximately 1) and to completely block deacylation of the acyl-enzyme. In contrast, acetylcholinesterase inhibition by gallamine followed the 'steric blockade hypothesis', i.e. only substrate association to as well as substrate/product dissociation from the active site were reduced in the presence of the inhibitor. The relative efficiency of the acetylcholinesterase-gallamine complex for the catalysis of substrate conversion was determined to be 1.7-25% of that of the free enzyme. Substrate hydrolysis and the inhibition of acetylcholinesterase were also investigated in the presence of 6% acetonitrile, and a competitive pseudo-inhibition was observed for acetonitrile (K(I) = 0.25 m). The interaction of acetylcholinesterase with acetonitrile and tacrine or gallamine resulted in a seven- to 10-fold increase in the K(I) values, whereas the principal mode of inhibition was not affected by the organic solvent. The determination of the inhibitory parameters of compound 1 in the presence of acetonitrile revealed that the substance acts as a hyperbolic mixed-type inhibitor of acetylcholinesterase. The complex formed by the enzyme and the inhibitor still catalysed product formation with 8.7-9.6% relative efficiency.
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Affiliation(s)
- Markus Pietsch
- Pharmaceutical Chemistry I, Pharmaceutical Institute, University of Bonn, Germany.
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26
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Pang YP, Singh SK, Gao Y, Lassiter TL, Mishra RK, Zhu KY, Brimijoin S. Selective and irreversible inhibitors of aphid acetylcholinesterases: steps toward human-safe insecticides. PLoS One 2009; 4:e4349. [PMID: 19194505 PMCID: PMC2632757 DOI: 10.1371/journal.pone.0004349] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Accepted: 12/30/2008] [Indexed: 11/20/2022] Open
Abstract
Aphids, among the most destructive insects to world agriculture, are mainly controlled by organophosphate insecticides that disable the catalytic serine residue of acetylcholinesterase (AChE). Because these agents also affect vertebrate AChEs, they are toxic to non-target species including humans and birds. We previously reported that a cysteine residue (Cys), found at the AChE active site in aphids and other insects but not mammals, might serve as a target for insect-selective pesticides. However, aphids have two different AChEs (termed AP and AO), and only AP-AChE carries the unique Cys. The absence of the active-site Cys in AO-AChE might raise concerns about the utility of targeting that residue. Herein we report the development of a methanethiosulfonate-containing small molecule that, at 6.0 µM, irreversibly inhibits 99% of all AChE activity extracted from the greenbug aphid (Schizaphis graminum) without any measurable inhibition of the human AChE. Reactivation studies using β-mercaptoethanol confirm that the irreversible inhibition resulted from the conjugation of the inhibitor to the unique Cys. These results suggest that AO-AChE does not contribute significantly to the overall AChE activity in aphids, thus offering new insight into the relative functional importance of the two insect AChEs. More importantly, by demonstrating that the Cys-targeting inhibitor can abolish AChE activity in aphids, we can conclude that the unique Cys may be a viable target for species-selective agents to control aphids without causing human toxicity and resistance problems.
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Affiliation(s)
- Yuan-Ping Pang
- Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, United States of America
- * E-mail: (YP); (SB)
| | - Sanjay K. Singh
- Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Yang Gao
- Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - T. Leon Lassiter
- Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Rajesh K. Mishra
- Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Kun Yan Zhu
- Department of Entomology, Kansas State University, Manhattan, Kansas, United States of America
| | - Stephen Brimijoin
- Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, United States of America
- * E-mail: (YP); (SB)
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27
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Carlier PR, Anderson TD, Wong DM, Hsu DC, Hartsel J, Ma M, Wong EA, Choudhury R, Lam PCH, Totrov MM, Bloomquist JR. Towards a species-selective acetylcholinesterase inhibitor to control the mosquito vector of malaria, Anopheles gambiae. Chem Biol Interact 2008; 175:368-75. [PMID: 18554580 DOI: 10.1016/j.cbi.2008.04.037] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 04/25/2008] [Accepted: 04/25/2008] [Indexed: 11/26/2022]
Abstract
Anopheles gambiae is the major mosquito vector of malaria in sub-Saharan Africa. At present, insecticide-treated nets (ITNs) impregnated with pyrethroid insecticides are widely used in malaria-endemic regions to reduce infection; however the emergence of pyrethroid-resistant mosquitoes has significantly reduced the effectiveness of the pyrethroid ITNs. An acetylcholinesterase (AChE) inhibitor that is potent for An. gambiae but weakly potent for the human enzyme could potentially be safely deployed on a new class of ITNs. In this paper we provide a preliminary pharmacological characterization of An. gambiae AChE, discuss structural features of An. gambiae and human AChE that could lead to selective inhibition, and describe compounds with 130-fold selectivity for inhibition of An. gambiae AChE relative to human AChE.
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Affiliation(s)
- Paul R Carlier
- Department of Chemistry, Virginia Tech, Blacksburg, VA 24061, USA.
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28
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Zheng ZH, Dong YS, Zhang H, Lu XH, Ren X, Zhao G, He JG, Si SY. Isolation and characterization of N98-1272 A, B and C, selective acetylcholinesterase inhibitors from metabolites of an actinomycete strain. J Enzyme Inhib Med Chem 2007; 22:43-9. [PMID: 17373546 DOI: 10.1080/14756360600988781] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
A high throughput screening was carried out in order to search for inhibitors of acetylcholinesterase (AChE) from microorganism metabolites. An actinomycete strain was found to produce active compounds named N98-1272 A, B and C with IC50 of 15.0, 11.5, 12.5 microM, respectively. Structural studies revealed that the three compounds are identical to the known antibiotics, Manumycin C, B and A. Kinetic analyses showed that N98-1272 C (Manumycin A) acted as a reversible noncompetitive inhibitor of acetylcholinesterase, with a Ki value of 7.2 microM. The cyclohexenone epoxide part of the structure plays a crucial role in the inhibitory activity against AChE. Compared with Tacrine, N98-1272 A, B, and C exhibit much better selectivity toward AChE over BuChE.
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Affiliation(s)
- Zhi-Hui Zheng
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, and Peking Union Medical College, Beijing 100050, China
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29
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Pang YP. Species marker for developing novel and safe pesticides. Bioorg Med Chem Lett 2007; 17:197-9. [PMID: 17046256 DOI: 10.1016/j.bmcl.2006.09.073] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Revised: 09/21/2006] [Accepted: 09/21/2006] [Indexed: 11/22/2022]
Abstract
Current anticholinesterase pesticides developed during World War II are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs) in insects and in mammals. A sequence analysis of AChEs from 68 species and three-dimensional models of the greenbug and English grain aphid AChEs reported herein reveal that a cysteine residue is present at the active sites of greenbug and aphid AChEs but absent at those of mammalian AChEs. This discovery enables the design of novel and safe pesticides that target the cysteine residue rather than the ubiquitous serine residue.
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Affiliation(s)
- Yuan-Ping Pang
- Computer-Aided Molecular Design Laboratory, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
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30
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Pang YP. Novel acetylcholinesterase target site for malaria mosquito control. PLoS One 2006; 1:e58. [PMID: 17183688 PMCID: PMC1762403 DOI: 10.1371/journal.pone.0000058] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Accepted: 10/25/2006] [Indexed: 11/21/2022] Open
Abstract
Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs) in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae) AChE (AgAChE) reported here show that C286 and R339 of AgAChE are conserved at the opening of the active site of AChEs in 17 invertebrate and four insect species, respectively. Both residues are absent in the active site of AChEs of human, monkey, dog, cat, cattle, rabbit, rat, and mouse. The 17 invertebrates include house mosquito, Japanese encephalitis mosquito, African malaria mosquito, German cockroach, Florida lancelet, rice leaf beetle, African bollworm, beet armyworm, codling moth, diamondback moth, domestic silkworm, honey bee, oat or wheat aphid, the greenbug, melon or cotton aphid, green peach aphid, and English grain aphid. The four insects are house mosquito, Japanese encephalitis mosquito, African malaria mosquito, and German cockroach. The discovery of the two invertebrate-specific residues enables the development of effective and safer pesticides that target the residues present only in mosquito AChEs rather than the ubiquitous serine residue, thus potentially offering an effective control of mosquito-borne malaria. Anti-AgAChE pesticides can be designed to interact with R339 and subsequently covalently bond to C286. Such pesticides would be toxic to mosquitoes but not to mammals.
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Affiliation(s)
- Yuan-Ping Pang
- Computer-Aided Molecular Design Laboratory, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America.
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31
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Bourne Y, Radic Z, Sulzenbacher G, Kim E, Taylor P, Marchot P. Substrate and Product Trafficking through the Active Center Gorge of Acetylcholinesterase Analyzed by Crystallography and Equilibrium Binding. J Biol Chem 2006; 281:29256-67. [PMID: 16837465 DOI: 10.1074/jbc.m603018200] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hydrolysis of acetylcholine catalyzed by acetylcholinesterase (AChE), one of the most efficient enzymes in nature, occurs at the base of a deep and narrow active center gorge. At the entrance of the gorge, the peripheral anionic site provides a binding locus for allosteric ligands, including substrates. To date, no structural information on substrate entry to the active center from the peripheral site of AChE or its subsequent egress has been reported. Complementary crystal structures of mouse AChE and an inactive mouse AChE mutant with a substituted catalytic serine (S203A), in various complexes with four substrates (acetylcholine, acetylthiocholine, succinyldicholine, and butyrylthiocholine), two non-hydrolyzable substrate analogues (m-(N,N,N-trimethylammonio)-trifluoroacetophenone and 4-ketoamyltrimethylammonium), and one reaction product (choline) were solved in the 2.05-2.65-A resolution range. These structures, supported by binding and inhibition data obtained on the same complexes, reveal the successive positions and orientations of the substrates bound to the peripheral site and proceeding within the gorge toward the active site, the conformations of the presumed transition state for acylation and the acyl-enzyme intermediate, and the positions and orientations of the dissociating and egressing products. Moreover, the structures of the AChE mutant in complexes with acetylthiocholine and succinyldicholine reveal additional substrate binding sites on the enzyme surface, distal to the gorge entry. Hence, we provide a comprehensive set of structural snapshots of the steps leading to the intermediates of catalysis and the potential regulation by substrate binding to various allosteric sites at the enzyme surface.
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Affiliation(s)
- Yves Bourne
- Ingénierie des Protéines, CNRS FRE-2738, Institut Fédératif de Recherche Jean Roche, Université dela Méditerranée, Faculté d eMédecine Secteur Nord, F-13916 Marseille Cedex 20, France
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32
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Wriggers W, Chakravarty S, Jennings PA. Control of protein functional dynamics by peptide linkers. Biopolymers 2006; 80:736-46. [PMID: 15880774 DOI: 10.1002/bip.20291] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Control of structural flexibility is essential for the proper functioning of a large number of proteins and multiprotein complexes. At the residue level, such flexibility occurs due to local relaxation of peptide bond angles whose cumulative effect may result in large changes in the secondary, tertiary or quaternary structures of protein molecules. Such flexibility, and its absence, most often depends on the nature of interdomain linkages formed by oligopeptides. Both flexible and relatively rigid peptide linkers are found in many multidomain proteins. Linkers are thought to control favorable and unfavorable interactions between adjacent domains by means of variable softness furnished by their primary sequence. Large-scale structural heterogeneity of multidomain proteins and their complexes, facilitated by soft peptide linkers, is now seen as the norm rather than the exception. Biophysical discoveries as well as computational algorithms and databases have reshaped our understanding of the often spectacular biomolecular dynamics enabled by soft linkers. Absence of such motion, as in so-called molecular rulers, also has desirable functional effects in protein architecture. We review here the historic discovery and current understanding of the nature of domains and their linkers from a structural, computational, and biophysical point of view. A number of emerging applications, based on the current understanding of the structural properties of peptides, are presented in the context of domain fusion of synthetic multifunctional chimeric proteins.
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Affiliation(s)
- Willy Wriggers
- School of Health Information Sciences and Institute of Molecular Medicine University of Texas, Health Science Center Houston, Houston, TX 77030, USA.
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33
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Hurley MM, Balboa A, Lushington GH, Guo J. Interactions of organophosphorus and related compounds with cholinesterases, a theoretical study. Chem Biol Interact 2005; 157-158:321-5. [PMID: 16289061 DOI: 10.1016/j.cbi.2005.10.096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acetylcholinesterase (AChE) is an interesting research target not only because of its high enzyme catalytic rate but also because of the wide range of health effects resulting from its inhibition. This paper discusses results of a theoretical study of acetylcholinesterase inhibition using several simulation techniques. In the first technique, a novel method was developed and used for predicting the binding affinity of human AChE (huAChE) inhibitors. Results are also presented for classical molecular dynamics and quantum mechanical simulations. Theoretical proton NMR shift results are obtained and compared to experiment, and the importance of the Glu199 residue is discussed in the context of the model.
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34
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Cusack B, Romanovskis P, Johnson JL, Etienne G, Rosenberry TL. (11) A novel strategy for protection against organophosphate toxicity: Evolution of cyclic inhibitors with high affinity for the acetylcholinesterase peripheral site. Chem Biol Interact 2005; 157-158:370. [PMID: 16429491 DOI: 10.1016/j.cbi.2005.10.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Bernadette Cusack
- Mayo Clinic College of Medicine, Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
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35
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Rosenberry TL, Johnson JL, Cusack B, Thomas JL, Emani S, Venkatasubban KS. Interactions between the peripheral site and the acylation site in acetylcholinesterase. Chem Biol Interact 2005; 157-158:181-9. [PMID: 16256966 DOI: 10.1016/j.cbi.2005.10.027] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Acetylcholinesterase (AChE) hydrolyzes its physiological substrate acetylcholine at one of the highest known catalytic rates. Two sites of ligand interaction have been identified: an acylation site or A-site at the base of the active site gorge, and a peripheral site or P-site at its mouth. Despite a wealth of information about the AChE structure and the role of specific residues in catalysis, an understanding of the catalytic mechanism and the role of the P-site has lagged far behind. In recent years we have clarified how the P- and A-sites interact to promote catalysis. Our studies have revealed that the P-site mediates substrate trapping and that ligand binding to the P-site can result in steric blockade of the A-site as well as allosteric activation. We have demonstrated this activation only for the acylation step of the catalytic reaction, but others have proposed that it involves the deacylation step. To investigate this point, we have measured the reaction of carbamoyl esters (carbamates) with AChE. With these slowly hydrolyzed substrates, the carbamoylation (acylation) and decarbamoylation (deacylation) steps can be resolved and analyzed separately. Carbamoylcholine is one of the closest structural analogs of acetylcholine, and we monitored these steps in continuous mixed assays with acetylthiocholine as a reporter substrate. At high concentrations of carbamoylcholine, decarbamoylation was inhibited but no activation of carbamoylation was observed. However, high concentrations of acetylthiocholine had no effect on the decarbamoylation rate constants. We concluded that the binding of acetylthiocholine to the P-site does not activate deacylation reactions.
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Affiliation(s)
- Terrone L Rosenberry
- Mayo Clinic College of Medicine, Department of Neuroscience, Jacksonville, FL 32224, USA.
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36
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Manojkumar TK, Cui C, Kim KS. Theoretical insights into the mechanism of acetylcholinesterase-catalyzed acylation of acetylcholine. J Comput Chem 2005; 26:606-11. [PMID: 15739192 DOI: 10.1002/jcc.20199] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Acylation of acetylcholine (ACh) catalyzed by acetylcholinesterase (AChE) has been studied using high-level theoretical calculations on a model system that mimics the reaction center of the enzyme, and compared with uncatalyzed acylation reaction. The geometries of all the intermediates and transition states, activation energies, and solvent effects have been calculated. The calculations predict simultaneous formation of two short-strong hydrogen bonds (SSHB) in the rate-determining transition state structures [the first SSHB involves the hydrogen atom of Ser-200 (H(s)) and another involves the hydrogen atom of His-440 (H(h))]. In the intermediate states, the H-bond corresponding to H(h) involves SSHB, whereas the one corresponding to H(s) does not.
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Affiliation(s)
- T K Manojkumar
- Creative Research Initiative Center for Superfunctional Materials, Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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37
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Erlanson DA, Hansen SK. Making drugs on proteins: site-directed ligand discovery for fragment-based lead assembly. Curr Opin Chem Biol 2004; 8:399-406. [PMID: 15288250 DOI: 10.1016/j.cbpa.2004.06.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Rapid progress in genomics and proteomics has provided a wealth of new targets for the pharmaceutical industry, even as many older targets still remain challenging for small-molecule drug discovery. Fragment-based lead discovery, in which leads are built progressively by expanding or combining small fragments, is a rapidly growing field that offers potential advantages over traditional lead-discovery processes. However, identifying and assembling the fragments themselves can be challenging. Here, we review the concept of site-directed ligand discovery, in which a covalent bond is used to stabilize the interaction between a low-affinity fragment and a target protein. We also describe how this technique can facilitate fragment-based lead discovery and help overcome some of the limitations of traditional screening methods.
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Affiliation(s)
- Daniel A Erlanson
- Sunesis Pharmaceuticals, Inc., 341 Oyster Point Boulevard, South San Francisco, California 94080, USA.
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