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Erramilli SK, Dominik PK, Ogbu CP, Kossiakoff AA, Vecchio AJ. Structural and biophysical insights into targeting of claudin-4 by a synthetic antibody fragment. Commun Biol 2024; 7:733. [PMID: 38886509 PMCID: PMC11183071 DOI: 10.1038/s42003-024-06437-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 06/11/2024] [Indexed: 06/20/2024] Open
Abstract
Claudins are a 27-member family of ~25 kDa membrane proteins that integrate into tight junctions to form molecular barriers at the paracellular spaces between endothelial and epithelial cells. As the backbone of tight junction structure and function, claudins are attractive targets for modulating tissue permeability to deliver drugs or treat disease. However, structures of claudins are limited due to their small sizes and physicochemical properties-these traits also make therapy development a challenge. Here we report the development of a synthetic antibody fragment (sFab) that binds human claudin-4 and the determination of a high-resolution structure of it bound to claudin-4/enterotoxin complexes using cryogenic electron microscopy. Structural and biophysical results reveal this sFabs mechanism of select binding to human claudin-4 over other homologous claudins and establish the ability of sFabs to bind hard-to-target claudins to probe tight junction structure and function. The findings provide a framework for tight junction modulation by sFabs for tissue-selective therapies.
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Affiliation(s)
- Satchal K Erramilli
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Pawel K Dominik
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
- Pfizer, San Diego, CA, 92121, USA
| | - Chinemerem P Ogbu
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- Department of Structural Biology, University at Buffalo, Buffalo, NY, 14203, USA
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Alex J Vecchio
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.
- Department of Structural Biology, University at Buffalo, Buffalo, NY, 14203, USA.
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2
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Hong L, Zahradka P, Taylor CG. Differential Modulation by Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) of Mesenteric Fat and Macrophages and T Cells in Adipose Tissue of Obese fa/ fa Zucker Rats. Nutrients 2024; 16:1311. [PMID: 38732558 PMCID: PMC11085824 DOI: 10.3390/nu16091311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/25/2024] [Accepted: 04/25/2024] [Indexed: 05/13/2024] Open
Abstract
Polyunsaturated fatty acids (PUFAs) can alter adipose tissue function; however, the relative effects of plant and marine n3-PUFAs are less clear. Our objective was to directly compare the n3-PUFAs, plant-based α-linolenic acid (ALA) in flaxseed oil, and marine-based eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in high-purity oils versus n6-PUFA containing linoleic acid (LA) for their effects on the adipose tissue and oral glucose tolerance of obese rats. Male fa/fa Zucker rats were assigned to faALA, faEPA, faDHA, and faLA groups and compared to baseline fa/fa rats (faBASE) and lean Zucker rats (lnLA). After 8 weeks, faEPA and faDHA had 11-14% lower body weight than faLA. The oral glucose tolerance and total body fat were unchanged, but faEPA had less mesenteric fat. faEPA and faDHA had fewer large adipocytes compared to faLA and faALA. EPA reduced macrophages in the adipose tissue of fa/fa rats compared to ALA and DHA, while faLA had the greatest macrophage infiltration. DHA decreased (~10-fold) T-cell infiltration compared to faBASE and faEPA, whereas faALA and faLA had an ~40% increase. The n3-PUFA diets attenuated tumour necrosis factor-α in adipose tissue compared to faBASE, while it was increased by LA in both genotypes. In conclusion, EPA and DHA target different aspects of inflammation in adipose tissue.
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Affiliation(s)
- Lena Hong
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada;
| | - Peter Zahradka
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada;
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Carla G. Taylor
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Albrechtsen Research Centre, Winnipeg, MB R2H 2A6, Canada;
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
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3
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Dong L, Malkowski MG. Defining the Conformational Ensembles Associated with Ligand Binding to Cyclooxygenase-2. Biochemistry 2023; 62:3134-3144. [PMID: 37852627 DOI: 10.1021/acs.biochem.3c00341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Cyclooxygenases (COX) catalyze the committed step in the production of prostaglandins responsible for the maintenance of physiological homeostasis. While crystal structures of COX in complex with substrates and inhibitors have provided insight into the molecular interactions governing their binding, they have not uncovered specific details related to the protein conformational motions responsible for important aspects of the COX function. We created a cysteine-free COX-2 construct and introduced a free cysteine at position-122 to enable labeling with 3-bromo-1,1,1-trifluoroacetone (BTFA). Placement of the label adjacent to the cyclooxygenase channel entrance permitted the detection of alterations upon ligand binding. 19F-nuclear magnetic resonance spectroscopy (19F-NMR) was then used to probe the conformational ensembles arising from BTFA-labeled COX-2 constructs in the presence and absence of ligands known to allosterically activate or inhibit COX-2. 19F-NMR analyses performed in the presence of the time-dependent inhibitor flurbiprofen, as well as Arg-120, Tyr-355, and Glu-524 mutations, led to the classification of two ensembles as representing the relaxed and tightened states of the cyclooxygenase channel entrance. A third ensemble, generated in the presence of arachidonic acid and the Y355F mutant and modulated by the allosteric potentiators palmitic acid and oleic acid and the nonallosteric substrates 2-arachidonoyl glycerol ether and anandamide, was classified as being related to the allosteric regulation of COX activity. The ensemble-based insight into COX function demonstrated here complements the static information derived from crystal structure analyses, collectively providing a more detailed framework of the dynamics involved in the regulation of COX catalysis and inhibition.
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Affiliation(s)
- Liang Dong
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, the State University of New York, Buffalo, New York 14203, United States
| | - Michael G Malkowski
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, the State University of New York, Buffalo, New York 14203, United States
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Rudrapal M, Eltayeb WA, Rakshit G, El-Arabey AA, Khan J, Aldosari SM, Alshehri B, Abdalla M. Dual synergistic inhibition of COX and LOX by potential chemicals from Indian daily spices investigated through detailed computational studies. Sci Rep 2023; 13:8656. [PMID: 37244921 PMCID: PMC10224994 DOI: 10.1038/s41598-023-35161-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 05/13/2023] [Indexed: 05/29/2023] Open
Abstract
Cyclooxygenase (COX) and Lipoxygenase (LOX) are essential enzymes for arachidonic acid (AA) to eicosanoids conversion. These AA-derived eicosanoids are essential for initiating immunological responses, causing inflammation, and resolving inflammation. Dual COX/5-LOX inhibitors are believed to be promising novel anti-inflammatory agents. They inhibit the synthesis of prostaglandins (PGs) and leukotrienes (LTs), but have no effect on lipoxin formation. This mechanism of combined inhibition circumvents certain limitations for selective COX-2 inhibitors and spares the gastrointestinal mucosa. Natural products, i.e. spice chemicals and herbs, offer an excellent opportunity for drug discovery. They have proven anti-inflammatory properties. However, the potential of a molecule to be a lead/ drug candidate can be much more enhanced if it has the property of inhibition in a dual mechanism. Synergistic activity is always a better option than the molecule's normal biological activity. Herein, we have explored the dual COX/5-LOX inhibition property of the three major potent phytoconsituents (curcumin, capsaicin, and gingerol) from Indian spices using in silico tools and biophysical techniques in a quest to identify their probable inhibitory role as anti-inflammatory agents. Results revealed the dual COX/5-LOX inhibitory potential of curcumin. Gingerol and capsaicin also revealed favorable results as dual COX/5-LOX inhibitors. Our results are substantiated by target similarity studies, molecular docking, molecular dynamics, energy calculations, DFT, and QSAR studies. In experimental inhibitory (in vitro) studies, curcumin exhibited the best dual inhibitory activities against COX-1/2 and 5-LOX enzymes. Capsaicin and gingerol also showed inhibitory potential against both COX and LOX enzymes. In view of the anti-inflammatory potential these spice chemicals, this research could pave the way for more scientific exploration in this area for drug discovery.
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Affiliation(s)
- Mithun Rudrapal
- Department of Pharmaceutical Sciences, School of Biotechnology and Pharmaceutical Sciences, Vignan's Foundation for Science, Technology & Research (Deemed to Be University), Guntur, 522213, India.
| | - Wafa Ali Eltayeb
- Biotechnology Department, Faculty of Science and Technology, Shendi University, Shendi, 414601, Sudan
| | - Gourav Rakshit
- Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Ranchi, 835215, India
| | - Amr Ahmed El-Arabey
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Cairo, 11651, Egypt
| | - Johra Khan
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al'Majmaah, 11952, Saudi Arabia.
- Health and Basic Sciences Research Center, Majmaah University, Al'Majmaah, 11952, Saudi Arabia.
| | - Sahar M Aldosari
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al'Majmaah, 11952, Saudi Arabia
- Health and Basic Sciences Research Center, Majmaah University, Al'Majmaah, 11952, Saudi Arabia
| | - Bader Alshehri
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al'Majmaah, 11952, Saudi Arabia
- Health and Basic Sciences Research Center, Majmaah University, Al'Majmaah, 11952, Saudi Arabia
| | - Mohnad Abdalla
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Jinan, 250022, People's Republic of China.
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Sung B, Kim HK, Baek AR, Yang BW, Kim YH, Choi G, Park HJ, Kim M, Lee J, Chang Y. Nonsteroidal Anti-Inflammatory Drug Conjugated with Gadolinium (III) Complex as an Anti-Inflammatory MRI Agent. Int J Mol Sci 2023; 24:ijms24076870. [PMID: 37047841 PMCID: PMC10095586 DOI: 10.3390/ijms24076870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/04/2023] [Accepted: 04/04/2023] [Indexed: 04/14/2023] Open
Abstract
Studies have been actively conducted to ensure that gadolinium-based contrast agents for magnetic resonance imaging (MRI) are accompanied by various biological functions. A new example is the anti-inflammatory theragnostic MRI agent to target inflammatory mediators for imaging diagnosis and to treat inflammatory diseases simultaneously. We designed, synthesized, and characterized a Gd complex of 1,4,7-tris(carboxymethylaza) cyclododecane-10-azaacetylamide (DO3A) conjugated with a nonsteroidal anti-inflammatory drug (NSAID) that exerts the innate therapeutic effect of NSAIDs and is also applicable in MRI diagnostics. Gd-DO3A-fen (0.1 mmol/kg) was intravenously injected into the turpentine oil-induced mouse model, with Gd-DO3A-BT as a control group. In the in vivo MRI experiment, the contrast-to-noise ratio (CNR) was higher and persisted longer than that with Gd-DO3A-BT; specifically, the CNR difference was almost five times at 2 h after injection. Gd-DO3A-fen had a binding affinity (Ka) of 6.68 × 106 M-1 for the COX-2 enzyme, which was 2.1-fold higher than that of fenbufen, the original NSAID. In vivo evaluation of anti-inflammatory activity was performed in two animal models. In the turpentine oil-induced model, the mRNA expression levels of inflammatory parameters such as COX-2, TNF-α, IL-1β, and IL-6 were reduced, and in the carrageenan-induced edema model, swelling was suppressed by 72% and there was a 2.88-fold inhibition compared with the saline group. Correlation analysis between in vitro, in silico, and in vivo studies revealed that Gd-DO3A-fen acts as an anti-inflammatory theragnostic agent by directly binding to COX-2.
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Affiliation(s)
- Bokyung Sung
- Department of Medical & Biological Engineering, Kyungpook National University, Jung-gu, Daegu 41944, Republic of Korea
| | - Hee-Kyung Kim
- Preclinical Research Center, Daegu-Gyeongbuk Medical Innovation Foundation (K-MEDI hub), Dong-gu, Daegu 41061, Republic of Korea
| | - Ah-Rum Baek
- Institute of Biomedical Engineering Research, Kyungpook National University, Jung-gu, Daegu 41566, Republic of Korea
| | - Byeong-Woo Yang
- Department of Medical & Biological Engineering, Kyungpook National University, Jung-gu, Daegu 41944, Republic of Korea
| | - Yeoun-Hee Kim
- R&D Center, Etnova Therapeutics Corp., Gwonseon-gu, Suwon-si 13120, Republic of Korea
| | - Garam Choi
- R&D Center, Etnova Therapeutics Corp., Gwonseon-gu, Suwon-si 13120, Republic of Korea
| | - Hyun-Jin Park
- R&D Center, Etnova Therapeutics Corp., Gwonseon-gu, Suwon-si 13120, Republic of Korea
| | - Minsup Kim
- Department of Biotechnology and Bioinformatics, Korea University Sejong Campus, 2511 Sejong-ro, Sejong City 30019, Republic of Korea
| | - Jongmin Lee
- Department of Radiology, Kyungpook National University Hospital, Jung-gu, Daegu 41944, Republic of Korea
| | - Yongmin Chang
- Department of Radiology, Kyungpook National University Hospital, Jung-gu, Daegu 41944, Republic of Korea
- Department of Molecular Medicine, School of Medicine, Kyungpook National University, Jung-gu, Daegu 41944, Republic of Korea
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6
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Koca M, Anıl B, Nişancı B, Bayır Y, Ercan Z, Özakar E. Synthesis of New Ester Derivatives of Salicylic Acid and Evaluation of Their COX Inhibitory Potential. Chem Biodivers 2023; 20:e202200509. [PMID: 36514919 DOI: 10.1002/cbdv.202200509] [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: 05/23/2022] [Revised: 12/07/2022] [Accepted: 12/07/2022] [Indexed: 12/15/2022]
Abstract
Salicylic acid is an NSAID with serious side effects on the GIS. The side effects of salicylic acid on the GIS are slightly reduced by acetylating salicylic acid. 12 new ester analogs of salicylic acid were synthesized with high yields in this study. The chemical structures of the synthesized compounds were characterized by 1 H-NMR, 13 C-NMR, and HRMS spectra. The inhibitory potential of the compounds was evaluated on COXs by in vitro and in silico studies. The COX2 inhibitory activity of the most potent inhibitor MEST1 (IC50 : 0.048 μM) was found to be much higher than the COX2 inhibitory activity of aspirin (IC50 : 2.60 μM). In docking studies, the strongest inhibitor among the compounds synthesized was predicted to be MEST1, with the lowest binding energy. Docking studies revealed that MEST1 extends from the hydrophobic channel to the top of the cyclooxygenase active site, forming various interactions with residues in the binding pocket.
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Affiliation(s)
- Mehmet Koca
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Atatürk University, Erzurum, 25240, Turkey
| | - Barış Anıl
- Department of Chemistry, Faculty of Sciences, Atatürk University, Erzurum, 25240, Turkey
| | - Bilal Nişancı
- Department of Chemistry, Faculty of Sciences, Atatürk University, Erzurum, 25240, Turkey
| | - Yasin Bayır
- Department of Biochemistry, Faculty of Pharmacy, Atatürk University, Erzurum, 25240, Turkey
| | - Zeynep Ercan
- Department of Biochemistry, Faculty of Pharmacy, Atatürk University, Erzurum, 25240, Turkey
| | - Emrah Özakar
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Atatürk University, Erzurum, 25240, Turkey
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7
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Eicosanoid production by macrophages during inflammation depends on the M1/M2 phenotype. Prostaglandins Other Lipid Mediat 2022; 160:106635. [PMID: 35307567 DOI: 10.1016/j.prostaglandins.2022.106635] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 03/09/2022] [Accepted: 03/15/2022] [Indexed: 11/24/2022]
Abstract
Macrophages are important in inflammation, and are involved in many physiological and pathological processes. Additionally, macrophages are important producers of eicosanoids, lipids that influence the inflammatory response. Our study aimed to explore the role of eicosanoids in the inflammatory response by studying the production of eicosanoids by macrophages on different stages of inflammation. Murine peritoneal macrophages (MPMs) were obtained at different stages of inflammation, which were then cultured in vitro with polyunsaturated fatty acids. Eicosanoids in MPMs were then detected by liquid chromatography-mass spectrometry. The metabolites derived from the cyclooxygenase (COX) pathway were increased, whereas those from the lipoxygenase (LOX) pathway were reduced. Additionally, the ratio of arachidonic acid (AA)-derived and eicosapentaenoic acid (EPA)-derived eicosanoids was dependent on the stage of inflammation. Moreover, the composition of macrophages with different phenotypes changed. To clarify the relationship between the phenotypes of macrophages and eicosanoids metabolism, we detected the eicosanoids in M1 and M2 differentiated THP-1 cells. Overall, M1 preferred AA, whereas M2 preferred EPA as substrate, which was related to the expression of COX and LOX. In conclusion, this study demonstrates that the difference in macrophage eicosanoids metabolism during the inflammatory response is related to the macrophage polarisation.
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Romero-Estrada A, Boto A, González-Christen J, Romero-Estudillo I, Garduño-Ramírez ML, Razo-Hernández RS, Marquina S, Maldonado-Magaña A, Columba-Palomares MC, Sánchez-Carranza JN, Alvarez L. Synthesis, Biological Evaluation, and Molecular Docking Study of 3-Amino and 3-Hydroxy- seco A Derivatives of α-Amyrin and 3-Epilupeol as Inhibitors of COX-2 Activity and NF-kB Activation. JOURNAL OF NATURAL PRODUCTS 2022; 85:787-803. [PMID: 35175765 DOI: 10.1021/acs.jnatprod.1c00827] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this study, a series of novel 3-seco-A derivatives of the natural triterpenes α-amyrin (1) and 3-epilupeol (2) were synthesized by a one-pot radical scission-oxidation procedure and evaluated in vitro and in vivo for their capacity to inhibit the inflammatory process. For the in vitro studies, the trans-4-hydroxy-l-proline methyl ester derivatives (1f and 2f) were consistently effective in inhibiting NO, IL-6, and TNF-α secretion, as well as inhibition of NF-κB activation, in RAW cells stimulated by LPS. The further in vivo anti-inflammatory study revealed that the trans-4-hydroxy-l-proline methyl ester derivatives (1f and 2f), together with 1g, were the most effective in inhibiting TPA-induced edema. Interestingly, the α-amyrin derivatives were the most potent inhibitors of COX-2, but inhibited COX-1 only to some extent. The hydroxyl derivative (1c) was selective for COX-2 inhibition (66.3 ± 1.1% at 17.5 μM) without affecting the COX-1 isoform and did not present toxicity. Molecular docking studies revealed that these compounds bind with their polar region in the cavity over Arg-120, and their lipophilic part is orientated to the HEM cofactor similarly to the natural substrate arachidonic acid in the catalytic site of COX-2. These results indicated that seco-A ursane derivatives could be considered promising candidates for the future development of selective NF-κB and COX-2 inhibitors.
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Affiliation(s)
- Antonio Romero-Estrada
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Morelos, México
- Departamento de Madera, Celulosa y Papel, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Km 15.5 Carretera Guadalajara-Nogales, Col. Las Agujas, Zapopan 45100, Jalisco, México
| | - Alicia Boto
- Instituto de Productos Naturales y Agrobiología del CSIC, Avenuda Astrofísico Francisco Sánchez 3, 38206-La Laguna, Tenerife, Spain
| | - Judith González-Christen
- Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209 Morelos, México
| | - Ivan Romero-Estudillo
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Morelos, México
- CONACYT-Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209 Morelos, México
| | - María Luisa Garduño-Ramírez
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Morelos, México
| | - Rodrigo Said Razo-Hernández
- Centro de Investigación en Dinámica Celular-IICBA, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Morelos, México
| | - Silvia Marquina
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Morelos, México
| | - Amalia Maldonado-Magaña
- Instituto Tecnológico de Milpa Alta. Independencia Sur No. 36, Col. San Salvador Cuauhténco, Alcaldía Milpa Alta CDMX 12300, México
| | - María C Columba-Palomares
- Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209 Morelos, México
| | - Jessica Nayelli Sánchez-Carranza
- Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209 Morelos, México
| | - Laura Alvarez
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Morelos, México
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9
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Spriha SE, Rahman FI, Rahman SMA. Synthesis, in vivo and in silico analgesic and anti-inflammatory studies of α-D-ribofuranose derivatives. Saudi Pharm J 2021; 29:981-991. [PMID: 34588844 PMCID: PMC8463446 DOI: 10.1016/j.jsps.2021.07.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 07/16/2021] [Indexed: 11/29/2022] Open
Abstract
Five α-D-ribofuranose analogues (2, 3, 4, 5 and 6) were synthesized in good yields from 3-O-benzyl-4-C-(hydroxymethyl)-1, 2-O-isopropylidene-α-D-ribofuranose (1). The synthesized compounds were then subjected to analgesic, anti-inflammatory, antimicrobial and antioxidant assays. Compound 3 demonstrated 79.74% (P < 0.001) writhing inhibition and highest reaction time of 2.55 ± 0.13 min (P < 0.001) after 30 min of oral administration in peripheral and central analgesic assay, respectively, at 50 mg/kg dose. Compound 2 and 6 exhibited significant anti-inflammatory activity at 100 mg/kg dose with paw edema inhibition of 91.15% (P < 0.001) and 95.13% (P < 0.001), respectively, in 4th hour. The synthesized analogues did not show notable antioxidant and antibacterial properties. Molecular docking study revealed higher binding affinity of −8.1 kcal/mol and −8.9 kcal/mol of compound 3 towards cyclooxygenase-1 and phospholipase A2, respectively, compared to −7.7 and −7.6 kcal/mol respectively for corresponding native ligands. Compound 2 demonstrated binding affinity of −9.1 kcal/mol towards interleukin-1 receptor-associated kinase-4 compared to −8.7 kcal/mol of the native ligand. The molecular properties related to drug likeness of compounds were found to be within acceptable range. Synthesized D-ribofuranose analogues demonstrated promising analgesic and anti-inflammatory activities and further development may lead to new potent analgesic and anti-inflammatory agents.
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Affiliation(s)
- Sabiha Enam Spriha
- Department of Clinical Pharmacy & Pharmacology, Faculty of Pharmacy, University of Dhaka, Dhaka 1000, Bangladesh
| | - Fahad Imtiaz Rahman
- Department of Clinical Pharmacy & Pharmacology, Faculty of Pharmacy, University of Dhaka, Dhaka 1000, Bangladesh
| | - S M Abdur Rahman
- Department of Clinical Pharmacy & Pharmacology, Faculty of Pharmacy, University of Dhaka, Dhaka 1000, Bangladesh
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10
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Su KH, Wu CT, Lin SW, Mori S, Liu WM, Yang HC. Calculation of CYP450 protein-ligand binding and dissociation free energy paths. J Chem Phys 2021; 155:025101. [PMID: 34266281 DOI: 10.1063/5.0046169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The function of an enzyme depends on its dynamic structure, and the catalytic mechanism has long been an active focus of research. The principle for interpreting protein selectivity and fidelity stems from optimization of the active site upon protein-substrate complexation, i.e., a lock-and-key configuration, on which most protein-substrate molecule binding recognition, and hence drug discovery, relies. Yet another thought has been to incorporate the protein folding interior tunnels for stereo- and regio-selectivity along the protein-substrate or protein-ligand/inhibitor binding process. Free energy calculations provide valuable information for molecular recognition and protein-ligand binding dynamics and kinetics. In this study, we focused on the kinetics of cytochrome P450 proteins (CYP450s) and the protein interior tunnel structure-dynamics relationship in terms of the substrate binding and leaving mechanism. A case in point is given by the prostaglandin H2 (PGH2) homologous isomerase of prostacyclin synthase. To calculate the reactant and product traversing the tunnels to and from the heme site, the free energy paths and tunnel potentials of mean force are constructed from steered molecular dynamics simulations and adaptive basing force umbrella sampling simulations. We explore the binding tunnels and critical residue lining characteristics for the ligand traverse and the underlying mechanism of CYP450 activity. Our theoretical analysis provides insights into the decisive role of the substrate tunnel binding process of the CYP450 mechanism and may be useful in drug design and protein engineering contexts.
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Affiliation(s)
- Kuan-Hsuan Su
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Chin-Teng Wu
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Shang-Wei Lin
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Seiji Mori
- Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Wei-Min Liu
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Hsiao-Ching Yang
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
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11
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Kumari P, Singh P, Kaur J, Bhatti R. Design, Synthesis, and Activity Evaluation of Stereoconfigured Tartarate Derivatives as Potential Anti-inflammatory Agents In Vitro and In Vivo. J Med Chem 2021; 64:9550-9566. [PMID: 34137625 DOI: 10.1021/acs.jmedchem.1c00880] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Preclinical and clinical data reveal that inflammation is strongly correlated with the pathogenesis of a number of diseases including those of cancer, Alzheimer, and diabetes. The inflammatory cascade involves a multitude of cytokines ending ultimately with the activation of COX-2/LOX for the production of prostaglandins and leukotrienes. While the available inhibitors for these enzymes suffer from nonoptimal selectivity, in particular for COX-2, we present here the results of purposely designed tartarate derivatives that exhibit favorable selectivity and significant effectiveness against COX-2 and LOX. Integrated approaches of molecular simulation, organic synthesis, and biochemical/physical experiments identified 15 inhibiting COX-2 and LOX with respective IC50 4 and 7 nM. At a dose of 5 mg kg-1 to Swiss albino mice, 15 reversed algesia by 65% and inflammation by 33% in 2-3 h. We find good agreement between experiments and simulations and use the simulations to rationalize our observations.
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12
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Elrayess R, Elgawish MS, Elewa M, Nafie MS, Elhady SS, Yassen ASA. Synthesis, 3D-QSAR, and Molecular Modeling Studies of Triazole Bearing Compounds as a Promising Scaffold for Cyclooxygenase-2 Inhibition. Pharmaceuticals (Basel) 2020; 13:ph13110370. [PMID: 33172102 PMCID: PMC7694773 DOI: 10.3390/ph13110370] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 10/26/2020] [Accepted: 11/03/2020] [Indexed: 02/07/2023] Open
Abstract
Targeting of cyclooxygenase-2 (COX-2) has emerged as a powerful tool for therapeutic intervention because the overexpression of this enzyme is synonymous with inflammation, cancer, and neurodegenerative diseases. Herein, a new series of 1,2,4-triazole Schiff bases scaffold with aryl and heteroaryl systems 9a–12d were designed, synthesized, structurally elucidated, and biologically evaluated as a potent COX-2 blocker. The rationale beyond the current study is to increase the molecule bulkiness allowing a selective binding to the unique hydrophobic pocket of COX-2. Among the triazole–thiazole hybrids, the one with the para-methoxy moiety linked to a phenyl ring 12d showed the highest In vitro selectivity by COX-2 inhibition assay (IC50 of 0.04 μM) and in situ anti-inflammatory activity when evaluated using the protein denaturation assay (IC50 of 0.88 μM) in comparison with commercially available selective COX-2 inhibitor, Celecoxib (IC50 of 0.05 μM). Towards the COX-2 selectivity, ligand-based three dimensional quantitative structures activity relationship (3D-QSAR) employing atomic-based and field-based approaches were performed and resulted in the necessity of triazole and thiazole/oxazole scaffolds for COX-2 blocking. Furthermore, the molecular modeling study indicated a high selectivity and promising affinity of our prepared compounds to COX-2, especially the hydrophobic pocket and the mouth of the active site holding hydrogen-bonding, hydrophobic, and electrostatic interactions. In Silico absorption, delivery, metabolism, and excretion (ADME) predictions showed that all the pharmacokinetic and physicochemical features are within the appropriate range for human use.
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Affiliation(s)
- Ranza Elrayess
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt; (R.E.); (M.E.)
| | - Mohamed Saleh Elgawish
- Medicinal Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt;
| | - Marwa Elewa
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt; (R.E.); (M.E.)
| | - Mohamed S. Nafie
- Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522, Egypt;
| | - Sameh S. Elhady
- Department of Natural Products, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - Asmaa S. A. Yassen
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt; (R.E.); (M.E.)
- Correspondence: ; Tel.: +20-1096206738; Fax: +20-064-3230741
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13
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Prasher P, Sharma M. "Azole" as privileged heterocycle for targeting the inducible cyclooxygenase enzyme. Drug Dev Res 2020; 82:167-197. [PMID: 33137216 DOI: 10.1002/ddr.21753] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/12/2020] [Accepted: 10/16/2020] [Indexed: 12/22/2022]
Abstract
An over-expression of COX-2 isoenzyme belonging to the Cyclooxygenase Enzyme Family triggers the overproduction of pro-inflammatory prostaglandins that instigate the development of chronic inflammation and related disorders. Hence, the rationally designed drugs for mitigating over-activity of COX-2 isoenzyme play a regulatory role toward the alleviation of the progression of these disorders. However, a selective COX-2 inhibition chemotherapy prompts several side effects that necessitate the identification of novel molecular scaffolds for deliberating state-of-the-art drug designing strategies. The heterocyclic "azole" scaffold, being polar and hydrophilic, possesses remarkable physicochemical advantages for designing physiologically active molecules capable of interacting with a wide range of biological components, including enzymes, peptides, and metabolites. The substituted derivatives of azole nuclei enable a comprehensive SAR analysis for the appraisal of bioactive profile of the deliberated molecules for obtaining the rationally designed compounds with prominent activities. The comprehensive SAR analysis readily prompted the identification of Y-shaped molecules and the eminence of bulkier group for COX-2 selective inhibition. This review presents an epigrammatic collation of the pharmacophore-profile of the chemotherapeutics based on azole motif for a selective targeting of the COX-2 isoenzyme.
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Affiliation(s)
- Parteek Prasher
- UGC Sponsored Centre for Advanced Studies, Department of Chemistry, Guru Nanak Dev University, Amritsar, India.,Department of Chemistry, University of Petroleum & Energy Studies, Energy Acres, Dehradun, India
| | - Mousmee Sharma
- UGC Sponsored Centre for Advanced Studies, Department of Chemistry, Guru Nanak Dev University, Amritsar, India.,Department of Chemistry, Uttaranchal University, Arcadia Grant, Dehradun, India
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14
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Taidi L, Maurady A, Britel MR. Molecular docking study and molecular dynamic simulation of human cyclooxygenase-2 (COX-2) with selected eutypoids. J Biomol Struct Dyn 2020; 40:1189-1204. [PMID: 32990169 DOI: 10.1080/07391102.2020.1823884] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Inflammation is a key factor linked to almost all chronic and degenerative diseases implicit with certain levels of pain. In studies, over the past few years, it has been discovered that prostaglandins are the main cause of this inflammation and therefore could be blocked. Although no steroidal medications can be effective, natural compounds may offer a safer and often an effective alternative treatment for pain relief, especially for long-term use. Hence to find out natural anti-inflammatory compounds, we have highlighted five important butenolides that are eutypoid A, B, C, D and E with structure similar to that of rofecoxib, by ADMET and druglikeness analysis, followed by molecular docking with human COX-2 enzyme. Molecular docking studies revealed the importance of hydrophobic and hydrophilic amino acid residues for the stability of the ligands and that eutypoids C and E are the best candidates for the synthetic drugs with binding energy of -10.39 kcal/mol and -9.87 kcal/mol, respectively. The resulting complexes were then subject to 50 ns molecular dynamics (MD) simulation studies with the GROMACS package to analyze the stability of docked protein-ligand complexes and to assess the fluctuation and conformational changes during protein-ligand interaction. From the RMSD, RMSF, number of hydrogen bonds, SASA, PCA and MM/PBSA binding free energy analysis, we have found that out of five selected compounds eutypoid E showed good binding free energy of -174.45 kJ/mol, which is also good in other structural analyses. This compound displayed excellent pharmacological and structural properties to be drug candidates.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Loubna Taidi
- Laboratory of Innovative Technology, University Abdelmalek Essaadi, Tangier, Morocco
| | - Amal Maurady
- Laboratory of Innovative Technology, University Abdelmalek Essaadi, Tangier, Morocco.,Faculty of Sciences and Technologies of Tangier, University Abdelmalek Essaadi, Tangier, Morocco
| | - Mohammed Reda Britel
- Laboratory of Innovative Technology, University Abdelmalek Essaadi, Tangier, Morocco
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15
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Rouzer CA, Marnett LJ. Structural and Chemical Biology of the Interaction of Cyclooxygenase with Substrates and Non-Steroidal Anti-Inflammatory Drugs. Chem Rev 2020; 120:7592-7641. [PMID: 32609495 PMCID: PMC8253488 DOI: 10.1021/acs.chemrev.0c00215] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cyclooxgenases are key enzymes of lipid signaling. They carry out the first step in the production of prostaglandins, important mediators of inflammation, pain, cardiovascular disease, and cancer, and they are the molecular targets for nonsteroidal anti-inflammatory drugs, which are among the oldest and most chemically diverse set of drugs known. Homodimeric proteins that behave as allosterically modulated, functional heterodimers, the cyclooxygenases exhibit complex kinetic behavior, requiring peroxide-dependent activation and undergoing suicide inactivation. Due to their important physiological and pathophysiological roles and keen interest on the part of the pharmaceutical industry, the cyclooxygenases have been the focus of a vast array of structural studies, leading to the publication of over 80 crystal structures of the enzymes in complex with substrates or inhibitors supported by a wealth of functional data generated by site-directed mutation experiments. In this review, we explore the chemical biology of the cyclooxygenases through the lens of this wealth of structural and functional information. We identify key structural features of the cyclooxygenases, break down their active site into regional binding pockets to facilitate comparisons between structures, and explore similarities and differences in the binding modes of the wide variety of ligands (both substrates and inhibitors) that have been characterized in complex with the enzymes. Throughout, we correlate structure with function whenever possible. Finally, we summarize what can and cannot be learned from the currently available structural data and discuss the critical intriguing questions that remain despite the wealth of information that has been amassed in this field.
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Affiliation(s)
- Carol A Rouzer
- A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Lawrence J Marnett
- A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
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16
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17
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Hajeyah AA, Griffiths WJ, Wang Y, Finch AJ, O’Donnell VB. The Biosynthesis of Enzymatically Oxidized Lipids. Front Endocrinol (Lausanne) 2020; 11:591819. [PMID: 33329396 PMCID: PMC7711093 DOI: 10.3389/fendo.2020.591819] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022] Open
Abstract
Enzymatically oxidized lipids are a specific group of biomolecules that function as key signaling mediators and hormones, regulating various cellular and physiological processes from metabolism and cell death to inflammation and the immune response. They are broadly categorized as either polyunsaturated fatty acid (PUFA) containing (free acid oxygenated PUFA "oxylipins", endocannabinoids, oxidized phospholipids) or cholesterol derivatives (oxysterols, steroid hormones, and bile acids). Their biosynthesis is accomplished by families of enzymes that include lipoxygenases (LOX), cyclooxygenases (COX), cytochrome P450s (CYP), and aldo-keto reductases (AKR). In contrast, non-enzymatically oxidized lipids are produced by uncontrolled oxidation and are broadly considered to be harmful. Here, we provide an overview of the biochemistry and enzymology of LOXs, COXs, CYPs, and AKRs in humans. Next, we present biosynthetic pathways for oxylipins, oxidized phospholipids, oxysterols, bile acids and steroid hormones. Last, we address gaps in knowledge and suggest directions for future work.
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Affiliation(s)
- Ali A. Hajeyah
- Systems Immunity Research Institute and Division of Infection and Immunity, Cardiff University, Cardiff, United Kingdom
- *Correspondence: Ali A. Hajeyah,
| | - William J. Griffiths
- Institute of Life Science, Swansea University Medical School, Swansea, United Kingdom
| | - Yuqin Wang
- Institute of Life Science, Swansea University Medical School, Swansea, United Kingdom
| | - Andrew J. Finch
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Valerie B. O’Donnell
- Systems Immunity Research Institute and Division of Infection and Immunity, Cardiff University, Cardiff, United Kingdom
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18
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Dong L, Anderson AJ, Malkowski MG. Arg-513 and Leu-531 Are Key Residues Governing Time-Dependent Inhibition of Cyclooxygenase-2 by Aspirin and Celebrex. Biochemistry 2019; 58:3990-4002. [PMID: 31469551 DOI: 10.1021/acs.biochem.9b00659] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aspirin and Celebrex are well-known time-dependent inhibitors of the cyclooxygenases (COX). Molecular dynamics simulations suggest that Arg-513 and Leu-531 contribute to the structural mechanisms of COX inhibition. We used mutagenesis and functional analyses to characterize how substitutions at these positions influence time-dependent inhibition by aspirin and Celebrex. We show that substitutions of Leu-531 with asparagine and phenylalanine significantly attenuate time-dependent inhibition of COX-2 by these drugs. The introduction of side chain bulk, rigidity, and charge would disrupt the formation of the initial noncovalent complex, in the case of aspirin, and the "high-affinity" binding state, in the case of Celebrex. Substitution of Arg-513 with histidine (the equivalent residue in COX-1) resulted in a 2-fold potentiation of aspirin inhibition, in support of the hypothesis that the presence of histidine in COX-1 lowers the activation barrier associated with the formation of the initial noncovalent enzyme-inhibitor complex. As a corollary, we previously hypothesized that the flexibility associated with Leu-531 contributes to the binding of arachidonic acid (AA) to acetylated COX-2 to generate 15R-hydroxyeicosatetraenoic acid (15R-HETE). We determined the X-ray crystal structure of AA bound to Co3+-protoporphyrin IX-reconstituted V349I murine COX-2 (muCOX-2). V349I muCOX-2 was utilized as a surrogate to trap AA in a conformation leading to 15R-HETE. AA binds in a C-shaped pose, facilitated by the rotation of the Leu-531 side chain. Ile-349 is positioned to sterically shield antarafacial oxygen addition at carbon-15 in a manner similar to that proposed for the acetylated Ser-530 side chain.
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Affiliation(s)
- Liang Dong
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences , University of Buffalo, the State University of New York , Buffalo , New York 14203 , United States
| | - Alyssa J Anderson
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences , University of Buffalo, the State University of New York , Buffalo , New York 14203 , United States
| | - Michael G Malkowski
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences , University of Buffalo, the State University of New York , Buffalo , New York 14203 , United States
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19
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Kaur B, Kaur M, Kaur N, Garg S, Bhatti R, Singh P. Engineered Substrate for Cyclooxygenase-2: A Pentapeptide Isoconformational to Arachidonic Acid for Managing Inflammation. J Med Chem 2019; 62:6363-6376. [PMID: 31244108 DOI: 10.1021/acs.jmedchem.9b00823] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Beyond the conventional mode of working of anti-inflammatory agents through enzyme inhibition, herein, COX-2 was provided with an alternate substrate. A proline-centered pentapeptide isoconformational to arachidonic acid, which exhibited appreciable selectivity for COX-2, overcoming acetic acid- and formalin-induced pain in rats to almost 80%, was treated as a substrate by the enzyme. Remarkably, COX-2 metabolized the pentapeptide into small fragments consisting mainly of di- and tripeptides that ensured the safe breakdown of the peptide under in vivo conditions. The kinetic parameter Kcat/Km for COX-2-mediated metabolism of the peptide (6.3 × 105 M-1 s-1) was quite similar to 9.5 × 105 M-1 s-1 for arachidonic acid. Evidenced by the molecular dynamic studies and the use of Y385F COX-2, it was observed that the breakage of the pentapeptide has probably been taken place through H-bond activation of the peptide bond by the side chains of Y385 and S530.
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20
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Smith WL, Malkowski MG. Interactions of fatty acids, nonsteroidal anti-inflammatory drugs, and coxibs with the catalytic and allosteric subunits of cyclooxygenases-1 and -2. J Biol Chem 2019; 294:1697-1705. [PMID: 30710016 DOI: 10.1074/jbc.tm118.006295] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Prostaglandin endoperoxide H synthases-1 and -2, commonly called cyclooxygenases-1 and -2 (COX-1 and -2), catalyze the committed step in prostaglandin biosynthesis-the conversion of arachidonic acid to prostaglandin endoperoxide H2 Both COX isoforms are sequence homodimers that function as conformational heterodimers having allosteric (Eallo) and catalytic (Ecat) subunits. At least in the case of COX-2, the enzyme becomes folded into a stable Eallo/Ecat pair. Some COX inhibitors (i.e. nonsteroidal anti-inflammatory drugs and coxibs) and common fatty acids (FAs) modulate Ecat activity by binding Eallo. However, the interactions and outcomes often differ between isoforms. For example, naproxen directly and completely inhibits COX-1 by binding Ecat but indirectly and incompletely inhibits COX-2 by binding Eallo. Additionally, COX-1 is allosterically inhibited up to 50% by common FAs like palmitic acid, whereas COX-2 is allosterically activated 2-fold by palmitic acid. FA binding to Eallo also affects responses to COX inhibitors. Thus, COXs are physiologically and pharmacologically regulated by the FA tone of the milieu in which each operates-COX-1 in the endoplasmic reticulum and COX-2 in the Golgi apparatus. Cross-talk between Eallo and Ecat involves a loop in Eallo immediately downstream of Arg-120. Mutational studies suggest that allosteric modulation requires a direct interaction between the carboxyl group of allosteric effectors and Arg-120 of Eallo; however, structural studies show some allosterically active FAs positioned in COX-2 in a conformation lacking an interaction with Arg-120. Thus, many details about the biological consequences of COX allosterism and how ligand binding to Eallo modulates Ecat remain to be resolved.
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Affiliation(s)
- William L Smith
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109.
| | - Michael G Malkowski
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, Buffalo, New York 14203.
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21
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Qiao J, Ma L, Roth J, Li Y, Liu Y. Kinetic basis for the activation of human cyclooxygenase-2 rather than cyclooxygenase-1 by nitric oxide. Org Biomol Chem 2019; 16:765-770. [PMID: 29308820 DOI: 10.1039/c7ob02992f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Numerous studies have shown that nitric oxide (NO) interacts with human cyclooxygenase (COX); however, conflicting results exist with respect to their interactions. Herein, recombinant human COX-1 and COX-2 were prepared and treated with NO donors individually under anaerobic and aerobic conditions. The S-nitrosylation detection and subsequent kinetic investigations into the arachidonic acid (AA) oxidation of COX enzymes indicate that NO S-nitrosylates both COX-1 and COX-2 in an oxygen-dependent manner, but enhances only the dioxygenase activity of COX-2. The solution viscosity, deuterium kinetic isotope effect (KIE), and oxygen-18 KIE experiments further demonstrate that NO activates COX-2 by altering the protein conformation to stimulate substrate association/product release and by accelerating the rate of hydrogen abstraction from AA by catalytic tyrosine radicals. These novel findings provide useful information for designing new drugs with less cardiotoxic effects that can block the interaction between NO and COX.
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Affiliation(s)
- Jie Qiao
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Science, Hubei University, Wuhan, Hubei 430062, China.
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22
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Scarpati M, Qi Y, Govind S, Singh S. A combined computational strategy of sequence and structural analysis predicts the existence of a functional eicosanoid pathway in Drosophila melanogaster. PLoS One 2019; 14:e0211897. [PMID: 30753230 PMCID: PMC6372189 DOI: 10.1371/journal.pone.0211897] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 01/22/2019] [Indexed: 02/07/2023] Open
Abstract
This study reports on a putative eicosanoid biosynthesis pathway in Drosophila melanogaster and challenges the currently held view that mechanistic routes to synthesize eicosanoid or eicosanoid-like biolipids do not exist in insects, since to date, putative fly homologs of most mammalian enzymes have not been identified. Here we use systematic and comprehensive bioinformatics approaches to identify most of the mammalian eicosanoid synthesis enzymes. Sensitive sequence analysis techniques identified candidate Drosophila enzymes that share low global sequence identities with their human counterparts. Twenty Drosophila candidates were selected based upon (a) sequence identity with human enzymes of the cyclooxygenase and lipoxygenase branches, (b) similar domain architecture and structural conservation of the catalytic domain, and (c) presence of potentially equivalent functional residues. Evaluation of full-length structural models for these 20 top-scoring Drosophila candidates revealed a surprising degree of conservation in their overall folds and potential analogs for functional residues in all 20 enzymes. Although we were unable to identify any suitable candidate for lipoxygenase enzymes, we report structural homology models of three fly cyclooxygenases. Our findings predict that the D. melanogaster genome likely codes for one or more pathways for eicosanoid or eicosanoid-like biolipid synthesis. Our study suggests that classical and/or novel eicosanoids mediators must regulate biological functions in insects–predictions that can be tested with the power of Drosophila genetics. Such experimental analysis of eicosanoid biology in a simple model organism will have high relevance to human development and health.
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Affiliation(s)
- Michael Scarpati
- Brooklyn College of the City University of New York, Brooklyn, New York, United States of America
- PhD program in Biology, Graduate Center of the City University of New York, New York, New York, United States of America
| | - Yan Qi
- Brooklyn College of the City University of New York, Brooklyn, New York, United States of America
- PhD program in Biology, Graduate Center of the City University of New York, New York, New York, United States of America
| | - Shubha Govind
- PhD program in Biology, Graduate Center of the City University of New York, New York, New York, United States of America
- PhD program in Biochemistry, Graduate Center of the City University of New York, New York, New York, United States of America
- The City College of the City University of New York, New York, New York, United States of America
| | - Shaneen Singh
- Brooklyn College of the City University of New York, Brooklyn, New York, United States of America
- PhD program in Biology, Graduate Center of the City University of New York, New York, New York, United States of America
- PhD program in Biochemistry, Graduate Center of the City University of New York, New York, New York, United States of America
- * E-mail:
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23
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Yang HC, Ge YC, Yang CH, Chao WC. Substrate Channeling of Prostaglandin H2 on the Stereochemical Control of a Cascade Cyclization Route. ACS Catal 2018. [DOI: 10.1021/acscatal.7b03687] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hsiao-Ching Yang
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Yung-Chi Ge
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Cheng-Han Yang
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Wei-Chih Chao
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
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24
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Goodman MC, Xu S, Rouzer CA, Banerjee S, Ghebreselasie K, Migliore M, Piomelli D, Marnett LJ. Dual cyclooxygenase-fatty acid amide hydrolase inhibitor exploits novel binding interactions in the cyclooxygenase active site. J Biol Chem 2018; 293:3028-3038. [PMID: 29326169 DOI: 10.1074/jbc.m117.802058] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 12/13/2017] [Indexed: 12/29/2022] Open
Abstract
The cyclooxygenases COX-1 and COX-2 oxygenate arachidonic acid (AA) to prostaglandin H2 (PGH2). COX-2 also oxygenates the endocannabinoids 2-arachidonoylglycerol (2-AG) and arachidonoylethanolamide (AEA) to the corresponding PGH2 analogs. Both enzymes are targets of nonsteroidal anti-inflammatory drugs (NSAIDs), but NSAID-mediated COX inhibition is associated with gastrointestinal toxicity. One potential strategy to counter this toxicity is to also inhibit fatty acid amide hydrolase (FAAH), which hydrolyzes bioactive fatty acid ethanolamides (FAEs) into fatty acids and ethanolamine. Here, we investigated the mechanism of COX inhibition by ARN2508, an NSAID that inhibits both COXs and FAAH with high potency, target selectivity, and decreased gastrointestinal toxicity in mouse models, presumably due to its ability to increase levels of FAEs. A 2.27-Å-resolution X-ray crystal structure of the COX-2·(S)-ARN2508 complex reveals that ARN2508 adopts a binding pose similar to that of its parent NSAID flurbiprofen. However, ARN2508's alkyl tail is inserted deep into the top channel, an active site region not exploited by any previously reported NSAID. As for flurbiprofen, ARN2508's potency is highly dependent on the configuration of the α-methyl group. Thus, (S)-ARN2508 is more potent than (R)-ARN2508 for inhibition of AA oxygenation by both COXs and 2-AG oxygenation by COX-2. Also, similarly to (R)-flurbiprofen, (R)-ARN2508 exhibits substrate selectivity for inhibition of 2-AG oxygenation. Site-directed mutagenesis confirms the importance of insertion of the alkyl tail into the top channel for (S)-ARN2508's potency and suggests a role for Ser-530 as a determinant of the inhibitor's slow rate of inhibition compared with that of (S)-flurbiprofen.
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Affiliation(s)
- Michael C Goodman
- From the A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology and Center in Molecular Toxicology, Vanderbilt Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Shu Xu
- From the A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology and Center in Molecular Toxicology, Vanderbilt Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Carol A Rouzer
- From the A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology and Center in Molecular Toxicology, Vanderbilt Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Surajit Banerjee
- the Northeastern Collaborative Access Team, Argonne National Laboratory, Argonne, Illinois 60439
| | - Kebreab Ghebreselasie
- From the A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology and Center in Molecular Toxicology, Vanderbilt Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Marco Migliore
- the Department of Drug Discovery and Development, Istituto Italiano di Tecnologia, 16163 Genoa, Italy
| | - Daniele Piomelli
- the Department of Drug Discovery and Development, Istituto Italiano di Tecnologia, 16163 Genoa, Italy.,the Departments of Anatomy, Neurobiology, Pharmacology, and Biological Chemistry, University of California, Irvine, California 92697, and
| | - Lawrence J Marnett
- From the A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology and Center in Molecular Toxicology, Vanderbilt Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232,
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Liao X, Wang W, Fan C, Yang N, Zhao J, Zhang Y, Gao R, Shen G, Xia S, Li G. Prokaryotic expression, purification and characterization of human cyclooxygenase-2. Int J Mol Med 2017; 40:75-82. [PMID: 28560423 PMCID: PMC5466394 DOI: 10.3892/ijmm.2017.3007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 05/26/2017] [Indexed: 01/06/2023] Open
Abstract
Cyclooxygenase-2 (COX-2) is a key enzyme which catalyzes the conversion of arachidonic acid (AA) into prostaglandins (PGs). It plays an important role in pathophysiological processes, such as tumorigenesis, angiogenesis, inflammation and tumor cell drug resistance. Therefore, COX-2 has been viewed as an important target for cancer therapy. The preparation of COX-2 protein is an important initial step for the subsequent development of COX-2 inhibitors. In this study, we report a strategy to heterologously express truncated human COX-2 (trCOX-2) in Escherichia coli (E. coli) BL21(DE3) host cells. Following denaturation, purification and renaturation, we successfully obtained enzymatically active trCOX-2 containing 257 residues of the C-terminus. Homology modeling and molecular docking analyses revealed that trCOX-2 retained the predicted 3D catalytic domain structure and AA could still bind to its hydrophobic groove. Western blot analysis and ELISA indicated that the trCOX-2 still retained its characteristic antigenicity and binding activity, while COX assays revealed that trCOX-2 maintained its enzyme activity. On the whole, in this study, we provided a novel method to isolate trCOX-2 possessing AA binding and catalytic activities. This study thus lays a foundation to facilitate further investigations of COX-2 and offers a valuable method with which to achieve the prokaryotic expression of a eukaryotic membrane protein.
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Affiliation(s)
- Xiangzhi Liao
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Wenhan Wang
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Chuanxi Fan
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Ning Yang
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Jialiang Zhao
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Ying Zhang
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Ruijuan Gao
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Guannan Shen
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Simin Xia
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Guiying Li
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
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Proschak E, Heitel P, Kalinowsky L, Merk D. Opportunities and Challenges for Fatty Acid Mimetics in Drug Discovery. J Med Chem 2017; 60:5235-5266. [PMID: 28252961 DOI: 10.1021/acs.jmedchem.6b01287] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Fatty acids beyond their role as an endogenous energy source and storage are increasingly considered as signaling molecules regulating various physiological effects in metabolism and inflammation. Accordingly, the molecular targets involved in formation and physiological activities of fatty acids hold significant therapeutic potential. A number of these fatty acid targets are addressed by some of the oldest and most widely used drugs such as cyclooxygenase inhibiting NSAIDs, whereas others remain unexploited. Compounds orthosterically binding to proteins that endogenously bind fatty acids are considered as fatty acid mimetics. On the basis of their structural resemblance, fatty acid mimetics constitute a family of bioactive compounds showing specific binding thermodynamics and following similar pharmacokinetic mechanisms. This perspective systematically evaluates targets for fatty acid mimetics, investigates their common structural characteristics, and highlights demands in their discovery and design. In summary, fatty acid mimetics share particularly favorable characteristics justifying the conclusion that their therapeutic potential vastly outweighs the challenges in their design.
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Affiliation(s)
- Ewgenij Proschak
- Institute of Pharmaceutical Chemistry, Goethe-University Frankfurt , Max-von-Laue-Straße 9, 60438 Frankfurt, Germany
| | - Pascal Heitel
- Institute of Pharmaceutical Chemistry, Goethe-University Frankfurt , Max-von-Laue-Straße 9, 60438 Frankfurt, Germany
| | - Lena Kalinowsky
- Institute of Pharmaceutical Chemistry, Goethe-University Frankfurt , Max-von-Laue-Straße 9, 60438 Frankfurt, Germany
| | - Daniel Merk
- Institute of Pharmaceutical Chemistry, Goethe-University Frankfurt , Max-von-Laue-Straße 9, 60438 Frankfurt, Germany
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27
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Abstract
Cyclooxygenase-2 isozyme is a promising anti-inflammatory drug target, and overexpression of this enzyme is also associated with several cancers and neurodegenerative diseases. The amino-acid sequence and structural similarity between inducible cyclooxygenase-2 and housekeeping cyclooxygenase-1 isoforms present a significant challenge to design selective cyclooxygenase-2 inhibitors. Herein, we describe the use of the cyclooxygenase-2 active site as a reaction vessel for the in situ generation of its own highly specific inhibitors. Multi-component competitive-binding studies confirmed that the cyclooxygenase-2 isozyme can judiciously select most appropriate chemical building blocks from a pool of chemicals to build its own highly potent inhibitor. Herein, with the use of kinetic target-guided synthesis, also termed as in situ click chemistry, we describe the discovery of two highly potent and selective cyclooxygenase-2 isozyme inhibitors. The in vivo anti-inflammatory activity of these two novel small molecules is significantly higher than that of widely used selective cyclooxygenase-2 inhibitors.Traditional inflammation and pain relief drugs target both cyclooxygenase 1 and 2 (COX-1 and COX-2), causing severe side effects. Here, the authors use in situ click chemistry to develop COX-2 specific inhibitors with high in vivo anti-inflammatory activity.
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28
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In situ click chemistry generation of cyclooxygenase-2 inhibitors. Nat Commun 2017; 8:1. [PMID: 28232747 PMCID: PMC5431875 DOI: 10.1038/s41467-016-0009-6] [Citation(s) in RCA: 3224] [Impact Index Per Article: 460.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 11/14/2016] [Indexed: 12/18/2022] Open
Abstract
Cyclooxygenase-2 isozyme is a promising anti-inflammatory drug target, and overexpression of this enzyme is also associated with several cancers and neurodegenerative diseases. The amino-acid sequence and structural similarity between inducible cyclooxygenase-2 and housekeeping cyclooxygenase-1 isoforms present a significant challenge to design selective cyclooxygenase-2 inhibitors. Herein, we describe the use of the cyclooxygenase-2 active site as a reaction vessel for the in situ generation of its own highly specific inhibitors. Multi-component competitive-binding studies confirmed that the cyclooxygenase-2 isozyme can judiciously select most appropriate chemical building blocks from a pool of chemicals to build its own highly potent inhibitor. Herein, with the use of kinetic target-guided synthesis, also termed as in situ click chemistry, we describe the discovery of two highly potent and selective cyclooxygenase-2 isozyme inhibitors. The in vivo anti-inflammatory activity of these two novel small molecules is significantly higher than that of widely used selective cyclooxygenase-2 inhibitors. Traditional inflammation and pain relief drugs target both cyclooxygenase 1 and 2 (COX-1 and COX-2), causing severe side effects. Here, the authors use in situ click chemistry to develop COX-2 specific inhibitors with high in vivo anti-inflammatory activity.
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29
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Dong L, Yuan C, Orlando BJ, Malkowski MG, Smith WL. Fatty Acid Binding to the Allosteric Subunit of Cyclooxygenase-2 Relieves a Tonic Inhibition of the Catalytic Subunit. J Biol Chem 2016; 291:25641-25655. [PMID: 27756840 DOI: 10.1074/jbc.m116.757310] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/13/2016] [Indexed: 01/24/2023] Open
Abstract
Prostaglandin endoperoxide H synthase-2 (PGHS-2), also called cyclooxygenase-2 (COX-2), converts arachidonic acid to PGH2 PGHS-2 is a conformational heterodimer composed of allosteric (Eallo) and catalytic (Ecat) subunits. Fatty acids (FAs) bind to Arg-120 of Eallo increasing to different degrees, depending on the FA, the Vmax of its Ecat partner. We report here that movement of helical residues 120-122 and loop residues 123-129 of Eallo underlies the allosteric effects of FAs and allosteric COX-2 inhibitors, including naproxen and flurbiprofen. An S121P substitution in both PGHS-2 monomers yields a variant (S121P/S121P PGHS-2) that has 1.7-1.8 times the Vmax of native PGHS-2 and is relatively insensitive to activation by FAs or inhibition by allosteric inhibitors. The S121P substitution in Eallo is primarily responsible for these effects. In X-ray crystal structures, the Cα atoms of helical residues 119-122 of S121P/S121P PGHS-2 are displaced from their normal positions. Additionally, the S121P/S121P PGHS-2 variants in which Pro-127 and Ser-541 are replaced by cysteines spontaneously forms Cys-127 to Cys-541 cross-links between monomers. This is unlike the corresponding native PGHS-2 variant and suggests that S121P substitutions also unhinge the loop involving residues 123-129. We conclude the following: (a) the region involving residues 120-129 of unoccupied Eallo tonically inhibits Ecat; (b) binding of an activating FA (e.g. arachidonic, palmitic, or oleic acid) to Eallo or an S121P substitution in Eallo repositions this region to increase Ecat activity; and (c) allosteric COX inhibitors act by preventing FA binding to Eallo and additionally by relocating Eallo residues to inhibit Ecat.
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Affiliation(s)
- Liang Dong
- From the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
| | - Chong Yuan
- From the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
| | - Benjamin J Orlando
- the Department of Structural Biology, University at Buffalo, The State University of New York, and the Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203
| | - Michael G Malkowski
- the Department of Structural Biology, University at Buffalo, The State University of New York, and the Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203
| | - William L Smith
- From the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
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30
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Orlando BJ, Malkowski MG. Crystal structure of rofecoxib bound to human cyclooxygenase-2. Acta Crystallogr F Struct Biol Commun 2016; 72:772-776. [PMID: 27710942 PMCID: PMC5053162 DOI: 10.1107/s2053230x16014230] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/07/2016] [Indexed: 11/11/2022] Open
Abstract
Rofecoxib (Vioxx) was one of the first selective cyclooxygenase-2 (COX-2) inhibitors (coxibs) to be approved for use in humans. Within five years after its release to the public, Vioxx was withdrawn from the market owing to the adverse cardiovascular effects of the drug. Despite the widespread knowledge of the development and withdrawal of Vioxx, relatively little is known at the molecular level about how the inhibitor binds to COX-2. Vioxx is unique in that the inhibitor contains a methyl sulfone moiety in place of the sulfonamide moiety found in other coxibs such as celecoxib and valdecoxib. Here, new crystallization conditions were identified that allowed the structural determination of human COX-2 in complex with Vioxx and the structure was subsequently determined to 2.7 Å resolution. The crystal structure provides the first atomic level details of the binding of Vioxx to COX-2. As anticipated, Vioxx binds with its methyl sulfone moiety located in the side pocket of the cyclooxygenase channel, providing support for the isoform selectivity of this drug.
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Affiliation(s)
- Benjamin J. Orlando
- Department of Structural Biology, The State University of New York at Buffalo and the Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
| | - Michael G. Malkowski
- Department of Structural Biology, The State University of New York at Buffalo and the Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
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31
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Orlando BJ, Malkowski MG. Substrate-selective Inhibition of Cyclooxygeanse-2 by Fenamic Acid Derivatives Is Dependent on Peroxide Tone. J Biol Chem 2016; 291:15069-81. [PMID: 27226593 DOI: 10.1074/jbc.m116.725713] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Indexed: 12/13/2022] Open
Abstract
Cyclooxygenase-2 (COX-2) catalyzes the oxygenation of arachidonic acid (AA) and endocannabinoid substrates, placing the enzyme at a unique junction between the eicosanoid and endocannabinoid signaling pathways. COX-2 is a sequence homodimer, but the enzyme displays half-of-site reactivity, such that only one monomer of the dimer is active at a given time. Certain rapid reversible, competitive nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to inhibit COX-2 in a substrate-selective manner, with the binding of inhibitor to a single monomer sufficient to inhibit the oxygenation of endocannabinoids but not arachidonic acid. The underlying mechanism responsible for substrate-selective inhibition has remained elusive. We utilized structural and biophysical methods to evaluate flufenamic acid, meclofenamic acid, mefenamic acid, and tolfenamic acid for their ability to act as substrate-selective inhibitors. Crystal structures of each drug in complex with human COX-2 revealed that the inhibitor binds within the cyclooxygenase channel in an inverted orientation, with the carboxylate group interacting with Tyr-385 and Ser-530 at the top of the channel. Tryptophan fluorescence quenching, continuous-wave electron spin resonance, and UV-visible spectroscopy demonstrate that flufenamic acid, mefenamic acid, and tolfenamic acid are substrate-selective inhibitors that bind rapidly to COX-2, quench tyrosyl radicals, and reduce higher oxidation states of the heme moiety. Substrate-selective inhibition was attenuated by the addition of the lipid peroxide 15-hydroperoxyeicosatertaenoic acid. Collectively, these studies implicate peroxide tone as an important mechanistic component of substrate-selective inhibition by flufenamic acid, mefenamic acid, and tolfenamic acid.
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Affiliation(s)
- Benjamin J Orlando
- From the Department of Structural Biology, The State University of New York at Buffalo and
| | - Michael G Malkowski
- From the Department of Structural Biology, The State University of New York at Buffalo and the Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203
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32
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Lucido MJ, Orlando BJ, Vecchio AJ, Malkowski MG. Crystal Structure of Aspirin-Acetylated Human Cyclooxygenase-2: Insight into the Formation of Products with Reversed Stereochemistry. Biochemistry 2016; 55:1226-38. [PMID: 26859324 DOI: 10.1021/acs.biochem.5b01378] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Aspirin and other nonsteroidal anti-inflammatory drugs target the cyclooxygenase enzymes (COX-1 and COX-2) to block the formation of prostaglandins. Aspirin is unique in that it covalently modifies each enzyme by acetylating Ser-530 within the cyclooxygenase active site. Acetylation of COX-1 leads to complete loss of activity, while acetylation of COX-2 results in the generation of the monooxygenated product 15(R)-hydroxyeicosatetraenoic acid (15R-HETE). Ser-530 has also been shown to influence the stereochemistry for the addition of oxygen to the prostaglandin product. We determined the crystal structures of S530T murine (mu) COX-2, aspirin-acetylated human (hu) COX-2, and huCOX-2 in complex with salicylate to 1.9, 2.0, and 2.4 Å, respectively. The structures reveal that (1) the acetylated Ser-530 completely blocks access to the hydrophobic groove, (2) the observed binding pose of salicylate is reflective of the enzyme-inhibitor complex prior to acetylation, and (3) the observed Thr-530 rotamer in the S530T muCOX-2 crystal structure does not impede access to the hydrophobic groove. On the basis of these structural observations, along with functional analysis of the S530T/G533V double mutant, we propose a working hypothesis for the generation of 15R-HETE by aspirin-acetylated COX-2. We also observe differential acetylation of COX-2 purified in various detergent systems and nanodiscs, indicating that detergent and lipid binding within the membrane-binding domain of the enzyme alters the rate of the acetylation reaction in vitro.
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Affiliation(s)
- Michael J Lucido
- Department of Structural Biology, The State University of New York at Buffalo and Hauptman-Woodward Medical Research Institute , Buffalo, New York 14203, United States
| | - Benjamin J Orlando
- Department of Structural Biology, The State University of New York at Buffalo and Hauptman-Woodward Medical Research Institute , Buffalo, New York 14203, United States
| | - Alex J Vecchio
- Department of Structural Biology, The State University of New York at Buffalo and Hauptman-Woodward Medical Research Institute , Buffalo, New York 14203, United States
| | - Michael G Malkowski
- Department of Structural Biology, The State University of New York at Buffalo and Hauptman-Woodward Medical Research Institute , Buffalo, New York 14203, United States
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33
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Liu Y, Roth JP. A Revised Mechanism for Human Cyclooxygenase-2. J Biol Chem 2016; 291:948-58. [PMID: 26565028 PMCID: PMC4705412 DOI: 10.1074/jbc.m115.668038] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 11/10/2015] [Indexed: 11/06/2022] Open
Abstract
The mechanism of ω-6 polyunsaturated fatty acid oxidation by wild-type cyclooxygenase 2 and the Y334F variant, lacking a conserved hydrogen bond to the catalytic tyrosyl radical/tyrosine, was examined for the first time under physiologically relevant conditions. The enzymes show apparent bimolecular rate constants and deuterium kinetic isotope effects that increase in proportion to co-substrate concentrations before converging to limiting values. The trends exclude multiple dioxygenase mechanisms as well as the proposal that initial hydrogen atom abstraction from the fatty acid is the first irreversible step in catalysis. Temperature dependent kinetic studies reinforce the novel finding that hydrogen transfer from the reduced catalytic tyrosine to a terminal peroxyl radical is the first irreversible step that controls regio- and stereospecific product formation.
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Affiliation(s)
- Yi Liu
- From the Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218
| | - Justine P Roth
- From the Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218
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34
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Audran G, Brémond P, Marque SR, Siri D, Santelli M. Energetics of the biosynthesis of prostanes from arachidonate. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.07.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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35
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Orlando BJ, Lucido MJ, Malkowski MG. The structure of ibuprofen bound to cyclooxygenase-2. J Struct Biol 2014; 189:62-6. [PMID: 25463020 DOI: 10.1016/j.jsb.2014.11.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/14/2014] [Accepted: 11/18/2014] [Indexed: 02/04/2023]
Abstract
The cyclooxygenases (COX-1 and COX-2) catalyze the rate-limiting step in the biosynthesis of prostaglandins, and are the pharmacological targets of non-steroidal anti-inflammatory drugs (NSAIDs) and COX-2 selective inhibitors (coxibs). Ibuprofen (IBP) is one of the most commonly available over-the-counter pharmaceuticals in the world. The anti-inflammatory and analgesic properties of IBP are thought to arise from inhibition of COX-2 rather than COX-1. While an X-ray crystal structure of IBP bound to COX-1 has been solved, no such structure exists for the cognate isoform COX-2. We have determined the crystal structure of muCOX-2 with a racemic mixture of (R/S)-IBP. Our structure reveals that only the S-isomer of IBP was bound, indicating that the S-isomer possesses higher affinity for COX-2 than the R-isomer. Mutational analysis of Arg-120 and Tyr-355 at the entrance of the cyclooxygenase channel confirmed their role in binding and inhibition of COX-2 by IBP. Our results provide the first atomic level detail of the interaction between IBP and COX-2.
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Affiliation(s)
- Benjamin J Orlando
- Department of Structural Biology, The State University of New York at Buffalo and the Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
| | - Michael J Lucido
- Department of Structural Biology, The State University of New York at Buffalo and the Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
| | - Michael G Malkowski
- Department of Structural Biology, The State University of New York at Buffalo and the Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA.
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36
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Revealing the macromolecular targets of complex natural products. Nat Chem 2014; 6:1072-8. [DOI: 10.1038/nchem.2095] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 09/23/2014] [Indexed: 01/01/2023]
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37
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Radwan MF, Dalby KN, Kaoud TS. Propyphenazone-based analogues as prodrugs and selective cyclooxygenase-2 inhibitors. ACS Med Chem Lett 2014; 5:983-8. [PMID: 25221653 DOI: 10.1021/ml500156v] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 06/23/2014] [Indexed: 01/01/2023] Open
Abstract
Improving the gastrointestinal safety profile of nonsteroidal anti-inflammatory drugs (NSAIDs) is an important goal. Herein, we report two strategies, using the nonacidic propyphenazone structure, with potential to overcome the side effects of NSAIDs. Propyphenazone was employed to temporarily mask the free acid group of the widely used NSAIDs ibuprofen, diclofenac, and ketoprofen to develop three mutual prodrugs hypothesized to have minimal GI irritation. The three prodrugs exhibit in vivo anti-inflammatory and analgesic activities with improved potency over each parent drug when compared to a nonhydrolyzable control betahistine-propyphenazone (BET-MP). Additionally, ANT-MP formed by the irreversible coupling of propyphenazone and 4-aminoantipyrine, displayed exceptional COXII selectivity (COXII IC50 of 0.97 ± 0.04 μM, compared to no observed inhibition of COXI at 160 μM). Inhibition of COXII suppresses inflammatory diseases without affecting COXI-mediated GI tract events. ANT-MP exhibited maximal analgesic effect when tested in vivo in an abdominal writhing assay (100% protection) and its anti-inflammatory activity showed a peak at 2 h in a carrageenan-induced paw edema model. Its unique selectivity toward the COXII enzyme was investigated using molecular modeling techniques.
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Affiliation(s)
- Mohamed F. Radwan
- Department
of Medicinal Chemistry, Faculty of Pharmacy, Minia University, 61519 Minia, Egypt
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Kingdome of Saudi Arabia
| | - Kevin N. Dalby
- Division
of Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Tamer S. Kaoud
- Department
of Medicinal Chemistry, Faculty of Pharmacy, Minia University, 61519 Minia, Egypt
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Kingdome of Saudi Arabia
- Division
of Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, United States
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38
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Kukk K, Kasvandik S, Samel N. N-glycosylation site occupancy in human prostaglandin H synthases expressed in Pichia pastoris. SPRINGERPLUS 2014; 3:436. [PMID: 25170432 PMCID: PMC4147080 DOI: 10.1186/2193-1801-3-436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 08/12/2014] [Indexed: 11/10/2022]
Abstract
Prostaglandin H synthases (PGHSs) are N-glycosylated membrane proteins that catalyse the committed step in prostaglandin synthesis. Unlike PGHS-2, the production of recombinant PGHS-1 in non-mammalian expression systems is complicated. The majority of the heterologous enzyme is inactive due to misfolding. Correct N-glycosylation is proposed to be obligatory for proper folding of mammalian PGHSs. In this study, human PGHS-1 and -2 (hPGHS-1 and -2) were expressed in the yeast Pichia pastoris. Recombinant hPGHS-2 was catalytically active, whereas hPGHS-1 was inactive. Accumulation of non-glycosylated hPGHSs was not observed in the crude lysate of the yeast cells. The N-glycosylation patterns of the purified recombinant proteins were characterised using nano-LC/MS/MS. The isoforms exhibited similar N-glycosylation site occupancy. The results indicate that there are more complex grounds for the inactivity of the recombinant hPGHS-1 produced in yeast.
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Affiliation(s)
- Kaia Kukk
- Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Sergo Kasvandik
- Proteomics Core Facility, Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Nigulas Samel
- Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
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39
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Kinetic Isotope Effect of Prostaglandin H Synthase Exhibits Inverted Temperature Dependence. Catalysts 2014. [DOI: 10.3390/catal4020174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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40
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Orlando BJ, McDougle DR, Lucido MJ, Eng ET, Graham LA, Schneider C, Stokes DL, Das A, Malkowski MG. Cyclooxygenase-2 catalysis and inhibition in lipid bilayer nanodiscs. Arch Biochem Biophys 2014; 546:33-40. [PMID: 24503478 DOI: 10.1016/j.abb.2014.01.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 01/15/2014] [Accepted: 01/24/2014] [Indexed: 11/26/2022]
Abstract
Cyclooxygenases (COX-1 and COX-2) oxygenate arachidonic acid (AA) to generate prostaglandins. The enzymes associate with one leaflet of the membrane bilayer. We utilized nanodisc technology to investigate the function of human (hu) COX-2 and murine (mu) COX-2 in a lipid bilayer environment. huCOX-2 and muCOX-2 were incorporated into nanodiscs composed of POPC, POPS, DOPC, or DOPS phospholipids. Size-exclusion chromatography and negative stain electron microscopy confirm that a single COX-2 homodimer is incorporated into the nanodisc scaffold. Nanodisc-reconstituted COX-2 exhibited similar kinetic profiles for the oxygenation of AA, eicosapentaenoic acid, and 1-arachidonoyl glycerol compared to those derived using detergent solubilized enzyme. Moreover, changing the phospholipid composition of the nanodisc did not alter the ability of COX-2 to oxygenate AA or to be inhibited by various nonselective NSAIDs or celecoxib. The cyclooxygenase activity of nanodisc-reconstituted COX-2 was reduced by aspirin acetylation and potentiated by the nonsubstrate fatty acid palmitic acid to the same extent as detergent solubilized enzyme, independent of phospholipid composition. The stabilization and maintenance of activity afforded by the incorporation of the enzyme into nanodiscs generates a native-like lipid bilayer environment to pursue studies of COX utilizing solution-based techniques that are otherwise not tractable in the presence of detergents.
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Affiliation(s)
- Benjamin J Orlando
- Department of Structural Biology, The State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Daniel R McDougle
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA; Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA; Department of Bioengineering and Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Michael J Lucido
- Department of Structural Biology, The State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Edward T Eng
- New York Structural Biology Center, New York, NY 10027, USA
| | - Leigh Ann Graham
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University Medical School, Nashville, TN 37232, USA
| | - Claus Schneider
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University Medical School, Nashville, TN 37232, USA
| | - David L Stokes
- New York Structural Biology Center, New York, NY 10027, USA
| | - Aditi Das
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA; Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA; Department of Bioengineering and Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
| | - Michael G Malkowski
- Department of Structural Biology, The State University of New York at Buffalo, Buffalo, NY 14203, USA; Hauptman-Woodward Medical Research Institute, Buffalo, NY 14203, USA.
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Xu S, Hermanson DJ, Banerjee S, Ghebreselasie K, Clayton GM, Garavito RM, Marnett LJ. Oxicams bind in a novel mode to the cyclooxygenase active site via a two-water-mediated H-bonding Network. J Biol Chem 2014; 289:6799-6808. [PMID: 24425867 DOI: 10.1074/jbc.m113.517987] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Oxicams are widely used nonsteroidal anti-inflammatory drugs (NSAIDs), but little is known about the molecular basis of the interaction with their target enzymes, the cyclooxygenases (COX). Isoxicam is a nonselective inhibitor of COX-1 and COX-2 whereas meloxicam displays some selectivity for COX-2. Here we report crystal complexes of COX-2 with isoxicam and meloxicam at 2.0 and 2.45 angstroms, respectively, and a crystal complex of COX-1 with meloxicam at 2.4 angstroms. These structures reveal that the oxicams bind to the active site of COX-2 using a binding pose not seen with other NSAIDs through two highly coordinated water molecules. The 4-hydroxyl group on the thiazine ring partners with Ser-530 via hydrogen bonding, and the heteroatom of the carboxamide ring of the oxicam scaffold interacts with Tyr-385 and Ser-530 through a highly coordinated water molecule. The nitrogen atom of the thiazine and the oxygen atom of the carboxamide bind to Arg-120 and Tyr-355 via another highly ordered water molecule. The rotation of Leu-531 in the structure opens a novel binding pocket, which is not utilized for the binding of other NSAIDs. In addition, a detailed study of meloxicam·COX-2 interactions revealed that mutation of Val-434 to Ile significantly reduces inhibition by meloxicam due to subtle changes around Phe-518, giving rise to the preferential inhibition of COX-2 over COX-1.
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Affiliation(s)
- Shu Xu
- A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Daniel J Hermanson
- A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Surajit Banerjee
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853; Northeastern Collaborative Access Team, Argonne National Laboratory, Argonne, Illinois 60439
| | - Kebreab Ghebreselasie
- A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Gina M Clayton
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - R Michael Garavito
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Lawrence J Marnett
- A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
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42
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Dong L, Sharma NP, Jurban BJ, Smith WL. Pre-existent asymmetry in the human cyclooxygenase-2 sequence homodimer. J Biol Chem 2013; 288:28641-55. [PMID: 23955344 DOI: 10.1074/jbc.m113.505503] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Prostaglandin endoperoxide H synthase-2 (PGHS-2), also known as cyclooxygenase-2 (COX-2), is a sequence homodimer. However, the enzyme exhibits half-site heme and inhibitor binding and functions as a conformational heterodimer having a catalytic subunit (Ecat) with heme bound and an allosteric subunit (Eallo) lacking heme. Some recombinant heterodimers composed of a COX-deficient mutant subunit and a native subunit (i.e. Mutant/Native PGHS-2) have COX activities similar to native PGHS-2. This suggests that the presence of heme plus substrate leads to the subunits becoming lodged in a semi-stable Eallo-mutant/Ecat-Native∼heme form during catalysis. We examined this concept using human PGHS-2 dimers composed of combinations of Y385F, R120Q, R120A, and S530A mutant or native subunits. With some heterodimers (e.g. Y385F/Native PGHS-2), heme binds with significantly higher affinity to the native subunit. This correlates with near native COX activity for the heterodimer. With other heterodimers (e.g. S530A/Native PGHS-2), heme binds with similar affinities to both subunits, and the COX activity approximates that expected for an enzyme in which each monomer contributes equally to the net COX activity. With or without heme, aspirin acetylates one-half of the subunits of the native PGHS-2 dimer, the Ecat subunits. Subunits having an S530A mutation are refractory to acetylation. Curiously, aspirin acetylates only one-quarter of the monomers of S530A/Native PGHS-2 with or without heme. This implies that there are comparable amounts of two noninterchangeable species of apoenzymes, Eallo-S530A/Ecat-Native and Eallo-Native/Ecat-S530A. These results suggest that native PGHS-2 assumes a reasonably stable, asymmetric Eallo/Ecat form during its folding and processing.
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Affiliation(s)
- Liang Dong
- From the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109
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43
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Varvas K, Kasvandik S, Hansen K, Järving I, Morell I, Samel N. Structural and catalytic insights into the algal prostaglandin H synthase reveal atypical features of the first non-animal cyclooxygenase. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:863-71. [DOI: 10.1016/j.bbalip.2012.11.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 11/06/2012] [Accepted: 11/27/2012] [Indexed: 10/27/2022]
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44
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Goulah CC, Zhu G, Koszelak-Rosenblum M, Malkowski MG. The crystal structure of α-Dioxygenase provides insight into diversity in the cyclooxygenase-peroxidase superfamily. Biochemistry 2013; 52:1364-72. [PMID: 23373518 PMCID: PMC3589821 DOI: 10.1021/bi400013k] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
α-Dioxygenases (α-DOX) oxygenate fatty acids into 2(R)-hydroperoxides. Despite the low level of sequence identity, α-DOX share common catalytic features with cyclooxygenases (COX), including the use of a tyrosyl radical during catalysis. We determined the X-ray crystal structure of Arabidopsis thaliana α-DOX to 1.5 Å resolution. The α-DOX structure is monomeric, predominantly α-helical, and comprised of two domains. The base domain exhibits a low degree of structural homology with the membrane-binding domain of COX but lies in a similar position with respect to the catalytic domain. The catalytic domain shows the highest degree of similarity with the COX catalytic domain, where 21 of the 22 α-helical elements are conserved. Helices H2, H6, H8, and H17 form the heme binding cleft and walls of the active site channel. His-318, Thr-323, and Arg-566 are located near the catalytic tyrosine, Tyr-386, at the apex of the channel, where they interact with a chloride ion. Substitutions at these positions coupled with kinetic analyses confirm previous hypotheses that implicate these residues as being involved in binding and orienting the carboxylate group of the fatty acid for optimal catalysis. Unique to α-DOX is the presence of two extended inserts on the surface of the enzyme that restrict access to the distal face of the heme, providing an explanation for the observed reduced peroxidase activity of the enzyme. The α-DOX structure represents the first member of the α-DOX subfamily to be structurally characterized within the cyclooxygenase-peroxidase family of heme-containing proteins.
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Affiliation(s)
| | - Guangyu Zhu
- Hauptman-Woodward Medical Research Institute, Buffalo, NY, 14203
| | - Mary Koszelak-Rosenblum
- Department of Structural Biology, The State University of New York at Buffalo, Buffalo, NY, 14203
| | - Michael G. Malkowski
- Hauptman-Woodward Medical Research Institute, Buffalo, NY, 14203,Department of Structural Biology, The State University of New York at Buffalo, Buffalo, NY, 14203,To whom correspondence should be addressed: Michael G. Malkowski, Ph.D., Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, New York 14203. Tel: (716) 898-8624; Fax: (716) 898-8660;
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