1
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Prostacyclin (PGI2) scaffolds in medicinal chemistry: current and emerging drugs. Med Chem Res 2022. [DOI: 10.1007/s00044-022-02914-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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2
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In silico design and in vitro assessment of anti-Helicobacter pylori compounds as potential small-molecule arginase inhibitors. Mol Divers 2022; 26:3365-3378. [PMID: 34997872 DOI: 10.1007/s11030-021-10371-8] [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: 10/07/2021] [Accepted: 12/15/2021] [Indexed: 02/07/2023]
Abstract
Related to a variety of gastrointestinal disorders ranging from gastric ulcer to gastric adenocarcinoma, the infection caused by the gram-negative bacteria Helicobacter pylori (H. pylori) poses as a great threat to human health; hence, the search for new treatments is a global priority. The H. pylori arginase (HPA) protein has been widely studied as one of the main virulence factors of this bacterium, being involved in the prevention of nitric oxide-mediated bacterial cell death, which is a central component of innate immunity. Given the growing need for the development of new drugs capable of combating the infection by H. pylori, the present work describes the search for new HPA inhibitors, using virtual screening techniques based on molecular docking followed by the evaluation of the proposed modes of interaction at the HPA active site. In vitro studies of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), followed by cytotoxicity activity in gastric adenocarcinoma and non-cancer cells, were performed. The results highlighted compounds 6, 11, and 13 as potential inhibitors of HPA; within these compounds, the results indicated 13 presented an improved activity toward H. pylori killing, with MIC and MBC both at 64 µg/mL. Moreover, compound 13 also presented a selectivity index of 8.3, thus being more selective for gastric adenocarcinoma cells compared to the commercial drug cisplatin. Overall, the present work demonstrates the search strategy based on in silico and in vitro techniques is able to support the rational design of new anti-H. pylori drugs.
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3
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Rendic SP, Peter Guengerich F. Human cytochrome P450 enzymes 5-51 as targets of drugs and natural and environmental compounds: mechanisms, induction, and inhibition - toxic effects and benefits. Drug Metab Rev 2019; 50:256-342. [PMID: 30717606 DOI: 10.1080/03602532.2018.1483401] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cytochrome P450 (P450, CYP) enzymes have long been of interest due to their roles in the metabolism of drugs, pesticides, pro-carcinogens, and other xenobiotic chemicals. They have also been of interest due to their very critical roles in the biosynthesis and metabolism of steroids, vitamins, and certain eicosanoids. This review covers the 22 (of the total of 57) human P450s in Families 5-51 and their substrate selectivity. Furthermore, included is information and references regarding inducibility, inhibition, and (in some cases) stimulation by chemicals. We update and discuss important aspects of each of these 22 P450s and questions that remain open.
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Affiliation(s)
| | - F Peter Guengerich
- b Department of Biochemistry , Vanderbilt University School of Medicine , Nashville , TN , USA
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4
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Gu M, Wang M, Guo J, Shi C, Deng J, Huang L, Huang L, Chang Z. Crystal structure of CYP76AH1 in 4-PI-bound state from Salvia miltiorrhiza. Biochem Biophys Res Commun 2019; 511:813-819. [DOI: 10.1016/j.bbrc.2019.02.103] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 02/20/2019] [Indexed: 11/28/2022]
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5
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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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6
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Seo MJ, Kang WR, Yang EJ, Shin KC, Ko YJ, Oh DK. Molecular characterization of Penicillium oxalicum 6R,8R-linoleate diol synthase with new regiospecificity. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:577-586. [PMID: 30342100 DOI: 10.1016/j.bbalip.2018.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 10/09/2018] [Accepted: 10/14/2018] [Indexed: 12/26/2022]
Abstract
Diol synthase-derived metabolites are involved in the sexual and asexual life cycles of fungi. A putative diol synthase from Penicillium oxalicum was found to convert palmitoleic acid (16:1n-7), oleic acid (18:1n-9), linoleic acid (18:2n-6), and α-linolenic acid (18:3n-3) to 6S,8R-dihydroxy-9(Z)-hexadecenoic acid, 6R,8R-dihydroxy-9(Z)-octadecenoic acid, 6R,8R-dihydroxy-9,12(Z,Z)-octadecadienoic acid, and 6S,8R-dihydroxy-9,12,15(Z,Z,Z)-octadecatrienoic acid, respectively, which were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR) spectroscopy analyses. The specific activity and catalytic efficiency of P. oxalicum 6,8-diol synthase were the highest for 18:2n-6, indicating that the enzyme is a 6R,8R-linoleate diol synthase (6R,8R-LDS) with new regiospecificity. This is the first report of a 6R,8R-LDS. LDS is a fusion protein consisting of a dioxygenase domain at the N-terminus and a cytochrome P450/hydroperoxide isomerase (P450/HPI) domain at the C-terminus. The putative active-site residues in the C-terminal domain of P. oxalicum 6R,8R-LDS were proposed based on a substrate-docking homology model. The results of the site-directed mutagenesis within C-terminal P450 domain suggested that Asn886, Arg707, and Arg934, are catalytic importance and belong to the catalytic groove. Phe794 and Gln889 were found to be involved in the regiospecific rearrangement of hydroperoxide, while the F794E and Q889A variants of P. oxalicum 6,8-LDS acted as 7,8- and 8,11-LDSs, respectively. All these mutations critically affected the HPI activity of P. oxalicum 6R,8R-LDS.
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Affiliation(s)
- Min-Ju Seo
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Woo-Ri Kang
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Eun-Joo Yang
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Kyung-Chul Shin
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Yoon-Joo Ko
- National Center for Inter-University Research Facilities (NCIRF), Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Deok-Kun Oh
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
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7
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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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8
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Yang HC, Yang CH, Huang MY, Lu JF, Wang JS, Yeh YQ, Jeng US. Homology Modeling and Molecular Dynamics Simulation Combined with X-ray Solution Scattering Defining Protein Structures of Thromboxane and Prostacyclin Synthases. J Phys Chem B 2017; 121:11229-11240. [PMID: 29168638 DOI: 10.1021/acs.jpcb.7b08299] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A combination of molecular dynamics (MD) simulations and X-ray scattering (SAXS) has emerged as the approach of choice for studying protein structures and dynamics in solution. This approach has potential applications for membrane proteins that neither are soluble nor form crystals easily. We explore the water-coupled dynamic structures of thromboxane synthase (TXAS) and prostacyclin synthase (PGIS) from scanning HPLC-SAXS measurements combined with MD ensemble analyses. Both proteins are heme-containing enzymes in the cytochrome P450 family, known as prostaglandin H2 (PGH2) isomerase, with counter-functions in regulation of platelet aggregation. Currently, the X-ray crystallographic structures of PGIS are available, but those for TXAS are not. The use of homology modeling of the TXAS structure with ns-μs explicit water solvation MD simulations allows much more accurate estimation of the configuration space with loop motion and origin of the protein behaviors in solution. In contrast to the stability of the conserved PGIS structure in solution, the pronounced TXAS flexibility has been revealed to have unstructured loop regions in connection with the characteristic P450 structural elements. The MD-derived and experimental-solution SAXS results are in excellent agreement. The significant protein internal motions, whole-molecule structures, and potential problems with protein folding, crystallization, and functionality are examined.
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Affiliation(s)
- Hsiao-Ching Yang
- 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
| | - Ming-Yi Huang
- Department of Chemistry, Fu Jen Catholic University , New Taipei City 24205, Taiwan
| | - Jyh-Feng Lu
- School of Medicine, Fu Jen Catholic University , New Taipei City 24205, Taiwan
| | - Jinn-Shyan Wang
- School of Medicine, Fu Jen Catholic University , New Taipei City 24205, Taiwan
| | - Yi-Qi Yeh
- National Synchrotron Radiation Research Center , Hsinchu Science Park, Hsinchu 30076, Taiwan
| | - U-Ser Jeng
- National Synchrotron Radiation Research Center , Hsinchu Science Park, Hsinchu 30076, Taiwan.,Department of Chemical Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan
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9
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HARA S. Prostaglandin terminal synthases as novel therapeutic targets. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2017; 93:703-723. [PMID: 29129850 PMCID: PMC5743848 DOI: 10.2183/pjab.93.044] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 07/21/2017] [Indexed: 06/07/2023]
Abstract
Non-steroidal anti-inflammatory drugs (NSAIDs) exert their anti-inflammatory and anti-tumor effects by reducing prostaglandin (PG) production via the inhibition of cyclooxygenase (COX). However, the gastrointestinal, renal and cardiovascular side effects associated with the pharmacological inhibition of the COX enzymes have focused renewed attention onto other potential targets for NSAIDs. PGH2, a COX metabolite, is converted to each PG species by species-specific PG terminal synthases. Because of their potential for more selective modulation of PG production, PG terminal synthases are now being investigated as a novel target for NSAIDs. In this review, I summarize the current understanding of PG terminal synthases, with a focus on microsomal PGE synthase-1 (mPGES-1) and PGI synthase (PGIS). mPGES-1 and PGIS cooperatively exacerbate inflammatory reactions but have opposing effects on carcinogenesis. mPGES-1 and PGIS are expected to be attractive alternatives to COX as therapeutic targets for several diseases, including inflammatory diseases and cancer.
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Affiliation(s)
- Shuntaro HARA
- Division of Health Chemistry, Department of Healthcare and Regulatory Sciences, School of Pharmacy, Showa University, Tokyo, Japan
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10
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Prostacyclin-producing human mesenchymal cells target H19 lncRNA to augment endogenous progenitor function in hindlimb ischaemia. Nat Commun 2016; 7:11276. [PMID: 27080438 PMCID: PMC4835554 DOI: 10.1038/ncomms11276] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 03/09/2016] [Indexed: 01/13/2023] Open
Abstract
Promoting the paracrine effects of human mesenchymal stem cell (hMSC) therapy may contribute to improvements in patient outcomes. Here we develop an innovative strategy to enhance the paracrine effects of hMSCs. In a mouse hindlimb ischaemia model, we examine the effects of hMSCs in which a novel triple-catalytic enzyme is introduced to stably produce prostacyclin (PGI2-hMSCs). We show that PGI2-hMSCs facilitate perfusion recovery and enhance running capability as compared with control hMSCs or iloprost (a stable PGI2 analogue). Transplanted PGI2-hMSCs do not incorporate long term into host tissue, but rather they mediate host regeneration and muscle mass gain in a paracrine manner. Mechanistically, this involves long noncoding RNA H19 in promoting PGI2-hMSC-associated survival and proliferation of host progenitor cells under hypoxic conditions. Together, our data reveal the novel ability of PGI2-hMSCs to stimulate host regenerative processes and improve physical function by regulating long noncoding RNA in resident progenitor cells. Human mesenchymal stem cells (hMSC) expressing paracrine factors may enhance therapeutic benefits when transplanted. Here, the authors show that hMSCs stably expressing prostacyclin enhance host regeneration and muscle mass gain in a mouse hindlimb ischaemia model, mediated by the long noncoding RNA H19.
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11
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Dorner ME, McMunn RD, Bartholow TG, Calhoon BE, Conlon MR, Dulli JM, Fehling SC, Fisher CR, Hodgson SW, Keenan SW, Kruger AN, Mabin JW, Mazula DL, Monte CA, Olthafer A, Sexton AE, Soderholm BR, Strom AM, Hati S. Comparison of intrinsic dynamics of cytochrome p450 proteins using normal mode analysis. Protein Sci 2015; 24:1495-507. [PMID: 26130403 DOI: 10.1002/pro.2737] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 04/18/2015] [Accepted: 06/14/2015] [Indexed: 12/24/2022]
Abstract
Cytochrome P450 enzymes are hemeproteins that catalyze the monooxygenation of a wide-range of structurally diverse substrates of endogenous and exogenous origin. These heme monooxygenases receive electrons from NADH/NADPH via electron transfer proteins. The cytochrome P450 enzymes, which constitute a diverse superfamily of more than 8,700 proteins, share a common tertiary fold but < 25% sequence identity. Based on their electron transfer protein partner, cytochrome P450 proteins are classified into six broad classes. Traditional methods of pro are based on the canonical paradigm that attributes proteins' function to their three-dimensional structure, which is determined by their primary structure that is the amino acid sequence. It is increasingly recognized that protein dynamics play an important role in molecular recognition and catalytic activity. As the mobility of a protein is an intrinsic property that is encrypted in its primary structure, we examined if different classes of cytochrome P450 enzymes display any unique patterns of intrinsic mobility. Normal mode analysis was performed to characterize the intrinsic dynamics of five classes of cytochrome P450 proteins. The present study revealed that cytochrome P450 enzymes share a strong dynamic similarity (root mean squared inner product > 55% and Bhattacharyya coefficient > 80%), despite the low sequence identity (< 25%) and sequence similarity (< 50%) across the cytochrome P450 superfamily. Noticeable differences in Cα atom fluctuations of structural elements responsible for substrate binding were noticed. These differences in residue fluctuations might be crucial for substrate selectivity in these enzymes.
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Affiliation(s)
- Mariah E Dorner
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Ryan D McMunn
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Thomas G Bartholow
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Brecken E Calhoon
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Michelle R Conlon
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Jessica M Dulli
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Samuel C Fehling
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Cody R Fisher
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Shane W Hodgson
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Shawn W Keenan
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Alyssa N Kruger
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Justin W Mabin
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Daniel L Mazula
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Christopher A Monte
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Augustus Olthafer
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Ashley E Sexton
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Beatrice R Soderholm
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Alexander M Strom
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
| | - Sanchita Hati
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702
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12
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Meling DD, Zelasko S, Kambalyal A, Roy J, Das A. Functional role of the conserved i-helix residue I346 in CYP5A1-Nanodiscs. Biophys Chem 2015; 200-201:34-40. [PMID: 25900452 DOI: 10.1016/j.bpc.2015.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/04/2015] [Accepted: 03/04/2015] [Indexed: 12/20/2022]
Abstract
Thromboxane synthase (CYP5A1) is a non-classical cytochrome P450 (CYP) expressed in human platelets that mediates vascular homeostasis by producing thromboxane A2 (TXA2) through the isomerization of prostaglandin H2 (PGH2). A homology alignment of CYP5A1 with human CYPs indicates that a highly conserved I-helix threonine residue is occupied by an isoleucine at position 346 in CYP5A1. We find that reverse-engineering CYP5A1 to contain either threonine or serine in this position dramatically increases TXA2 formation. Interestingly, the levels of malondialdehyde (MDA), a homolytic fragmentation product of PGH2 formed via a pathway independent of TXA2 formation, remain constant. Furthermore, spectral analysis using two PGH2 substrate analogs supports the observed activity changes in the hydroxyl-containing mutants. The more constrained active site of the I346T mutant displays altered PGH2 substrate analog binding properties. Together these studies provide new mechanistic insights into CYP5A1 mediated isomerization of PGH2 with respect to a critical active site residue.
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Affiliation(s)
- Daryl D Meling
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana IL 61802, USA
| | - Susan Zelasko
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, Urbana IL 61802, USA
| | - Amogh Kambalyal
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, Urbana IL 61802, USA
| | - Jahnabi Roy
- Department of Chemistry, University of Illinois Urbana-Champaign, IL 61802, USA
| | - Aditi Das
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana IL 61802, USA; Department of Comparative Biosciences, University of Illinois Urbana-Champaign, Urbana IL 61802, USA; Beckman Institute for Advanced Science and Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana IL 61802, USA.
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13
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Analysis of genetic polymorphism and biochemical characterization of a functionally decreased variant in prostacyclin synthase gene (CYP8A1) in humans. Arch Biochem Biophys 2015; 569:10-8. [PMID: 25623425 DOI: 10.1016/j.abb.2015.01.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 01/03/2015] [Accepted: 01/13/2015] [Indexed: 11/23/2022]
Abstract
Prostacyclin synthase (CYP8A1) is an enzyme responsible for the biosynthesis of prostacyclin (PGI2) which inhibits platelet activation and exhibits anti-inflammatory effect. The objectives of this study were to identify CYP8A1 genetic variants and characterize functional consequences of CYP8A1 variants. In total, 27 variants including four previously unidentified single-nucleotide polymorphisms (SNPs) were identified by direct DNA sequencing in Koreans (n=48). Among them, CYP8A1 A447T and E314Stop were newly assigned as CYP8A1(∗)5 and CYP8A1(∗)6 by the Human Cytochrome P450 Allele Nomenclature Committee, respectively. CYP8A1(∗)5 was found in the heme binding area in three individuals as a heterozygous mutation. To investigate the functional change of CYP8A1(∗)5, CYP8A1(∗)5 and wild-type CYP8A1 protein were overexpressed in an Escherichia coli expression system and purified. Metabolism of PGH2 by the CYP8A1(∗)5 protein exhibited significantly decreased activity, resulting in a 45% decrease in Vmax and a 1.8-fold decrease in intrinsic clearance compared to the wild-type. Based on the predicted crystal structure of CYP8A1(∗)5 using the Molecular Operating Environment platform, the distance from CYP8A1 Cys441 to the heme was altered with a significantly changed binding free energy for the mutant protein. Further studies would be needed to determine the effect of CYP8A1(∗)5 on PGI2 levels in humans.
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14
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Tempel W, Grabovec I, MacKenzie F, Dichenko YV, Usanov SA, Gilep AA, Park HW, Strushkevich N. Structural characterization of human cholesterol 7α-hydroxylase. J Lipid Res 2014; 55:1925-32. [PMID: 24927729 DOI: 10.1194/jlr.m050765] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Hepatic conversion to bile acids is a major elimination route for cholesterol in mammals. CYP7A1 catalyzes the first and rate-limiting step in classic bile acid biosynthesis, converting cholesterol to 7α-hydroxycholesterol. To identify the structural determinants that govern the stereospecific hydroxylation of cholesterol, we solved the crystal structure of CYP7A1 in the ligand-free state. The structure-based mutation T104L in the B' helix, corresponding to the nonpolar residue of CYP7B1, was used to obtain crystals of complexes with cholest-4-en-3-one and with cholesterol oxidation product 7-ketocholesterol (7KCh). The structures reveal a motif of residues that promote cholest-4-en-3-one binding parallel to the heme, thus positioning the C7 atom for hydroxylation. Additional regions of the binding cavity (most distant from the access channel) are involved to accommodate the elongated conformation of the aliphatic side chain. Structural complex with 7KCh shows an active site rigidity and provides an explanation for its inhibitory effect. Based on our previously published data, we proposed a model of cholesterol abstraction from the membrane by CYP7A1 for metabolism. CYP7A1 structural data provide a molecular basis for understanding of the diversity of 7α-hydroxylases, on the one hand, and cholesterol-metabolizing enzymes adapted for their specific activity, on the other hand.
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Affiliation(s)
- Wolfram Tempel
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Irina Grabovec
- Institute of Bioorganic Chemistry NAS of Belarus, Minsk, 220141 Belarus
| | - Farrell MacKenzie
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | | | - Sergey A Usanov
- Institute of Bioorganic Chemistry NAS of Belarus, Minsk, 220141 Belarus
| | - Andrei A Gilep
- Institute of Bioorganic Chemistry NAS of Belarus, Minsk, 220141 Belarus
| | - Hee-Won Park
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112
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15
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Affiliation(s)
- Thomas L. Poulos
- Departments of Molecular Biology & Biochemistry, Pharmaceutical Sciences, and Chemistry, University of California Irvine, Irvine, California 92697-3900
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16
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Hoffmann I, Oliw EH. 7,8- and 5,8-Linoleate diol synthases support the heterolytic scission of oxygen-oxygen bonds by different amide residues. Arch Biochem Biophys 2013; 539:87-91. [PMID: 24060467 DOI: 10.1016/j.abb.2013.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 09/11/2013] [Accepted: 09/13/2013] [Indexed: 11/18/2022]
Abstract
Linoleate diol synthases (LDS) are fungal dioxygenase-cytochrome P450 fusion enzymes. They oxidize 18:2n-6 sequentially to 8R-hydroperoxylinoleic acid (8R-HPODE) and 7S,8S- or 5S,8R-dihydroxylinoleic acids (DiHODE) by intramolecular oxygen transfer. The P450 domains contain a conserved sequence, Ala-Asn-Gln-Xaa-Gln, presumably located in the I-helices. The Asn938Leu replacement of 7,8-LDS of Gaeumannomyces graminis virtually abolished and the Asn938Asp and Asn938Gln replacements reduced the hydroperoxide isomerase activity. Gln941Leu and Gln941Glu substitutions had little effects. Replacements of the homologous Asn(887) and Gln(890) residues of 5,8-LDS of Aspergillus fumigatus yielded the opposite results. Asn887Leu and Asn887Gln of 5,8-LDS retained 5,8-DiHODE as the main metabolite with an increased formation of 6,8- and 8,11-DiHODE, whereas Gln890Leu almost abolished the 5,8-LDS activity. Replacement of Gln(890) with Glu also retained 5,8-DiHODE as the main product, but shifted oxygenation from C-5 to C-7 and C-11 and to formation of epoxyalcohols by homolytic scission of 8R-HPODE. P450 hydroxylases usually contain an "acid-alcohol" pair in the I-helices for the heterolytic scission of O2 and formation of compound I (Por(+) Fe(IV)=O) and water. The function of the acid-alcohol pair appears to be replaced by two different amide residues, Asn(938) of 7,8-LDS and Gln(890) of 5,8-LDS, for heterolysis of 8R-HPODE to generate compound I.
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Affiliation(s)
- Inga Hoffmann
- Department of Pharmaceutical Biosciences, Division of Biochemical Pharmacology, Uppsala Biomedical Center, Uppsala University, SE-75124 Uppsala, Sweden
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17
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Chu WT, Zheng QC. Conformational changes of enzymes and DNA in molecular dynamics: influenced by pH, temperature, and ligand. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2013; 92:179-217. [PMID: 23954102 DOI: 10.1016/b978-0-12-411636-8.00005-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Protein conformation, which has been a research hotspot for human diseases, is an important factor of protein properties. Recently, a series of approaches have been utilized to investigate the conformational changes under different conditions. Some of them have gained promising achievements, but it is still deficient in the detail researches at the atomic level. In this chapter, a series of computational examples of protein conformational changes under different pH environment, temperature, and ligand binding are described. We further show some useful methods, such as constant pH molecular dynamics simulations, molecular docking, and molecular mechanics Poisson-Boltzmann surface area/generalized Born surface area calculations. In comparison with the experimental results, the methods mentioned above are reasonable to detect and predict the interaction between residue and residue, residue and DNA, and residue and ligand. Additionally, some crucial interactions that cause protein conformational changes are discovered and discussed in this chapter. In summary, our work can give penetrating information to understand the pH-, temperature-, and ligand-induced conformational change mechanisms.
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Affiliation(s)
- Wen-Ting Chu
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, PR China
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18
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Abstract
X-ray crystal structures are available for 29 eukaryotic microsomal, chloroplast, or mitochondrial cytochrome P450s, including two non-monooxygenase P450s. These structures provide a basis for understanding structure-function relations that underlie their distinct catalytic activities. Moreover, structural plasticity has been characterized for individual P450s that aids in understanding substrate binding in P450s that mediate drug clearance.
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Affiliation(s)
- Eric F Johnson
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA.
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19
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Hoffmann I, Jernerén F, Oliw EH. Expression of fusion proteins of Aspergillus terreus reveals a novel allene oxide synthase. J Biol Chem 2013; 288:11459-69. [PMID: 23479731 DOI: 10.1074/jbc.m113.458257] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Aspergilli oxidize C18 unsaturated fatty acids by dioxygenase-cytochrome P450 fusion proteins to signal molecules involved in reproduction and host-pathogen interactions. Aspergillus terreus expresses linoleate 9R-dioxygenase (9R-DOX) and allene oxide synthase (AOS) activities in membrane fractions. The genome contains five genes (ATEG), which may code for a 9R-DOX-AOS fusion protein. The genes were cloned and expressed, but none of them oxidized 18:2n-6 to 9R-hydroperoxy-10(E),12(Z)-octadecadienoic acid (9R-HPODE). ATEG_02036 transformed 9R-HPODE to an unstable allene oxide, 9(R),10-epoxy-10,12(Z)-octadecadienoic acid. A substitution in the P450 domain (C1073S) abolished AOS activity. The N964V and N964D mutants both showed markedly reduced AOS activity, suggesting that Asn(964) may facilitate homolytic cleavage of the dioxygen bond of 9R-HPODE with formation of compound II in analogy with plant AOS (CYP74) and prostacyclin synthase (CYP8A1). ATEG_03992 was identified as 5,8-linoleate diol synthase (5,8-LDS). Replacement of Asn(878) in 5,8-LDS with leucine (N878L) mainly shifted ferryl oxygen insertion from C-5 toward C-6, but replacements of Gln(881) markedly affected catalysis. The Q881L mutant virtually abolished the diol synthase activity. Replacement of Gln(881) with Asn, Glu, Asp, or Lys residues augmented the homolytic cleavage of 8R-HPODE with formation of 10-hydroxy-8(9)-epoxy-12(Z)-octadecenoic acid (erythro/threo, 1-4:1) and/or shifted ferryl oxygen insertion from C-5 toward C-11. We conclude that homolysis and heterolysis of the dioxygen bond with formation of compound II in AOS and compound I in 5,8-LDS are influenced by Asn and Gln residues, respectively, of the I-helices. AOS of A. terreus appears to have evolved independently of CYP74 but with an analogous reaction mechanism.
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Affiliation(s)
- Inga Hoffmann
- Division of Biochemical Pharmacology, Department of Pharmaceutical Biosciences, Uppsala Biomedical Center, Uppsala University, SE-75124 Uppsala, Sweden
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20
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Chao WC, Lu JF, Wang JS, Yang HC, Pan TA, Chou SCW, Wang LH, Chou PT. Probing Ligand Binding to Thromboxane Synthase. Biochemistry 2013; 52:1113-21. [DOI: 10.1021/bi301400t] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wei-Chih Chao
- School of Medicine, Fu-Jen Catholic University, New Taipei, Taiwan, R.
O. C
| | - Jyh-Feng Lu
- School of Medicine, Fu-Jen Catholic University, New Taipei, Taiwan, R.
O. C
| | - Jinn-Shyan Wang
- School of Medicine, Fu-Jen Catholic University, New Taipei, Taiwan, R.
O. C
| | - Hsiao-Ching Yang
- Department of Chemistry, Fu-Jen Catholic University, New Taipei, Taiwan, R.
O. C
| | - Tai-An Pan
- Department of Chemistry, Fu-Jen Catholic University, New Taipei, Taiwan, R.
O. C
| | | | - Lee-Ho Wang
- Division of Hematology, Department
of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas 77030, United
States
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei, Taiwan, R. O. C
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21
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Narayanankutty A, Reséndiz-Hernández JM, Falfán-Valencia R, Teran LM. Biochemical pathogenesis of aspirin exacerbated respiratory disease (AERD). Clin Biochem 2012; 46:566-78. [PMID: 23246457 DOI: 10.1016/j.clinbiochem.2012.12.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 11/14/2012] [Accepted: 12/04/2012] [Indexed: 12/30/2022]
Abstract
Aspirin exacerbated respiratory disease (AERD) is a distinct clinical entity characterized by eosinophilic rhinosinusitis, asthma and often nasal polyposis. Exposure to aspirin or other nonsteroid anti-inflammatory drugs (NSAIDs) exacerbates bronchospasms with asthma and rhinitis. Disease progression suggests a skewing towards TH2 type cellular response along with moderate to severe eosinophil and mast cell infiltration. Alterations in upper and lower airway cellular milieu with abnormalities in eicosanoid metabolism and altered eicosanoid receptor expression are the key features underlying AERD pathogenesis. Dysregulation of arachidonic acid (AA) metabolism, notably reduced prostaglandin E2 (PGE2) synthesis compared to their aspirin tolerant counterpart and relatively increased PGD2 production, a TH2/eosinophil chemoattractant are reported in AERD. Underproduced PGE2 is metabolized by overexpression of 15 prostaglandin dehydrogenase (15-PGDH) to inactive products further reducing PGE2 at real time. This relives the inhibitory effect of PGE2 on 5-lipoxygenase (5-LOX) resulting in overproduction of cysteinyl leukotrienes (CysLTs). Diminished formation of CysLT antagonists called lipoxins (LXs) also augments CysLTs responsiveness. Occasional intake of NSAIDs favors even more 5-LOX product formation, further narrowing the bronchoconstrictive bottle neck, resulting in acute asthmatic exacerbations along with increased mucus production. This review focuses on abnormalities in biochemical and molecular mechanisms in eicosanoid biosynthesis, eicosanoid receptor dysregulation and associated polymorphisms with special reference to arachidonic acid metabolism in AERD.
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Affiliation(s)
- Arun Narayanankutty
- Department of Immunoallergy and Asthma, Instituto Nacional de Enfermedades Respiratorias Ismael Cosio Villegas, Calzada de Tlalpan 4502, Col. Sección XVI, Delegación Tlalpan, C.P. 14080, Mexico.
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22
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Cárdenas-Rodríguez N, Lara-Padilla E, Bandala C, López-Cruz J, Uscanga-Carmona C, Lucio-Monter PF, Floriano-Sánchez E. CYP2W1, CYP4F11 and CYP8A1 polymorphisms and interaction of CYP2W1 genotypes with risk factors in Mexican women with breast cancer. Asian Pac J Cancer Prev 2012; 13:837-46. [PMID: 22631658 DOI: 10.7314/apjcp.2012.13.3.837] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Breast cancer (BCa) is the leading type of cancer in Mexican women. Genetic factors, such as single nucleotide polymorphisms (SNP) of P450 system, have been reported in BCa. In this report, and for the first time in the literature, we analyzed the rs3735684 (7021 G>A), rs11553651 (15016 G>T) and rs56195291 (60020 C>G) polymorphisms in the CYP2W1, 4F11 and 8A1 genes in patients with BCa and in healthy Mexican women to identify a potential association between these polymorphisms and BCa risk. Patients and controls were used for polymorphism analysis using an allelic discrimination assay with TaqMan probes and confirmed by DNA sequencing. Links with clinic-pathological characteristics were also analyzed. Statistical analysis was performed using the standard χ2 or Fisher exact test statistic. No significant differences were observed in the distributions of CYP2W1 (OR 8.6, 95%CI 0.43-172.5 P>0.05; OR 2.0, 95%CI 0.76-5.4, P>0.05) and CYP4F11 (OR 0.3, 95%CI 0.01-8.4 P>0.05) genotypes between the patients and controls. Only the CYP8A1 CC genotype was detected in patients with BCa and the controls. All polymorphism frequencies were in Hardy-Weinberg Equilibrium (HWE) in the controls (P>0.05). We found a significant association between BCa risk and smoking, use of oral contraceptives or hormonal replacement therapy (HRT), obesity, hyperglycemia, chronic diseases, family history of cancer and menopausal status in the population studied (P<0.05). Tobacco, oral contraceptive or HRT, chronic diseases and obesity or overweight were strongly associated with almost eight, thirty-five, nine and five-fold increased risk for BCa. Tobaco, obesity and hyperglycemia significantly increased the risk of BCa in the patients carrying variant genotypes of CYP2W1 (P<0.05). These results indicate that the CYP2W1 rs3735684, CYP4F11 rs11553651 and CYP8A1 rs56195291 SNPs are not a key risk factor for BCa in Mexican women. This study did not detect an association between the CYP2W1, 4F11 and 8A1 genes polymorphisms and BCa risk in a Mexican population. However, some clinico-pathological risk factors interact with CYP2W1 genotypes and modifies susceptibility to BCa.
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Affiliation(s)
- N Cárdenas-Rodríguez
- Section of Research and Graduate Studies, Instituto Politecnico Nacional, Mexico.
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23
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Cui YL, Zhang JL, Zheng QC, Niu RJ, Xu Y, Zhang HX, Sun CC. Structural and Dynamic Basis of Human Cytochrome P450 7B1: A Survey of Substrate Selectivity and Major Active Site Access Channels. Chemistry 2012. [DOI: 10.1002/chem.201202627] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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24
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Chao WC, Lu JF, Wang JS, Yang HC, Chen HH, Lan YK, Yu YC, Chou PT, Wang LH. Probing the Interaction between Prostacyclin Synthase and Prostaglandin H2 Analogues or Inhibitors via a Combination of Resonance Raman Spectroscopy and Molecular Dynamics Simulation Approaches. J Am Chem Soc 2011; 133:18870-9. [DOI: 10.1021/ja206918w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
| | | | | | | | | | | | - Ya-Chien Yu
- Department of Chemistry, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Lee-Ho Wang
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, United States
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25
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Siam A, Brancale A, Simons C. Comparative modeling of 25-hydroxycholesterol-7α-hydroxylase (CYP7B1): ligand binding and analysis of hereditary spastic paraplegia type 5 CYP7B1 mutations. J Mol Model 2011; 18:441-53. [DOI: 10.1007/s00894-011-1084-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 04/06/2011] [Indexed: 02/06/2023]
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Sirim D, Widmann M, Wagner F, Pleiss J. Prediction and analysis of the modular structure of cytochrome P450 monooxygenases. BMC STRUCTURAL BIOLOGY 2010; 10:34. [PMID: 20950472 PMCID: PMC3224734 DOI: 10.1186/1472-6807-10-34] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 10/15/2010] [Indexed: 02/05/2023]
Abstract
Background Cytochrome P450 monooxygenases (CYPs) form a vast and diverse family of highly variable sequences. They catalyze a wide variety of oxidative reactions and are therefore of great relevance in drug development and biotechnological applications. Despite their differences in sequence and substrate specificity, the structures of CYPs are highly similar. Although being in research focus for years, factors mediating selectivity and activity remain vague. Description This systematic comparison of CYPs based on the Cytochrome P450 Engineering Database (CYPED) involved sequence and structure analysis of more than 8000 sequences. 31 structures have been applied to generate a reliable structure-based HMM profile in order to predict structurally conserved regions. Therefore, it was possible to automatically transfer these modules on CYP sequences without any secondary structure information, to analyze substrate interacting residues and to compare interaction sites with redox partners. Conclusions Functionally relevant structural sites of CYPs were predicted. Regions involved in substrate binding were analyzed in all sequences among the CYPED. For all CYPs that require a reductase, two reductase interaction sites were identified and classified according to their length. The newly gained insights promise an improvement of engineered enzyme properties for potential biotechnological application. The annotated sequences are accessible on the current version of the CYPED. The prediction tool can be applied to any CYP sequence via the web interface at http://www.cyped.uni-stuttgart.de/cgi-bin/strpred/dosecpred.pl.
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Affiliation(s)
- Demet Sirim
- Institute of Technical Biochemistry, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
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Tu T, Drăguşanu M, Petre BA, Rempel DL, Przybylski M, Gross ML. Protein-peptide affinity determination using an h/d exchange dilution strategy: application to antigen-antibody interactions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2010; 21:1660-1667. [PMID: 20444623 PMCID: PMC2932787 DOI: 10.1016/j.jasms.2010.03.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Revised: 03/15/2010] [Accepted: 03/16/2010] [Indexed: 05/27/2023]
Abstract
A new methodology using hydrogen/deuterium amide exchange (HDX) to determine the binding affinity of protein-peptide interactions is reported. The method, based on our previously established approach, protein ligand interaction by mass spectrometry, titration, and H/D exchange (PLIMSTEX) [J. Am. Chem. Soc.2003, 125, 5252-5253], makes use of a dilution strategy (dPLIMSTEX) for HDX, using the mass of the peptide ligand as readout. We employed dPLIMSTEX to study the interaction of calcium-saturated calmodulin with the opioid peptide β-endorphin as a model system; the affinity results are in good agreement with those from traditional PLIMSTEX and with literature values obtained by using other methods. We show that the dPLIMSTEX method is feasible to quantify an antigen-antibody interaction involving a 3-nitrotyrosine modified peptide in complex with a monoclonal anti-nitrotyrosine antibody. A dissociation constant in the low nanomolar range was determined, and a binding stoichiometry of antibody/peptide of 1:2 was confirmed. In addition, we determined that the epitope in the binding interface contains a minimum of five amino acids. The dPLIMSTEX approach is a sensitive and powerful tool for the quantitative determination of peptide affinities with antibodies, complementary to conventional immuno-analytical techniques.
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Affiliation(s)
- Tingting Tu
- Center for Biomedical and Bioorganic Mass Spectrometry, Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130
| | - Mihaela Drăguşanu
- Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
| | - Brînduşa-Alina Petre
- Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
| | - Don L. Rempel
- Center for Biomedical and Bioorganic Mass Spectrometry, Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130
| | - Michael Przybylski
- Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
| | - Michael L. Gross
- Center for Biomedical and Bioorganic Mass Spectrometry, Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130
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28
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López G, Ezkurdia I, Tress ML. Assessment of ligand binding residue predictions in CASP8. Proteins 2010; 77 Suppl 9:138-46. [PMID: 19714771 DOI: 10.1002/prot.22557] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Here we detail the assessment process for the binding site prediction category of the eighth Critical Assessment of Protein Structure Prediction experiment (CASP8). Predictions were only evaluated for those targets that bound biologically relevant ligands and were assessed using the Matthews Correlation Coefficient. The results of the analysis clearly demonstrate that three predictors from two groups (Lee and Sternberg) stand out from the rest. A further two groups perform well over subsets of metal binding or nonmetal ligand binding targets. The best methods were able to make consistently reliable predictions based on model structures, though it was noticeable that the two targets that were not well predicted were also the hardest targets. The number of predictors that submitted new methods in this category was highly encouraging and suggests that current technology is at the level that experimental biochemists and structural biologists could benefit from what is clearly a growing field.
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Affiliation(s)
- Gonzalo López
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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Abstract
BACKGROUND Prostaglandin H2 (PGH2) is a common precursor for the synthesis of five different Prostanoids via specific Prostanoid Synthases. The binding of this substrate with these Synthases is not properly understood. Moreover, currently no crystal structure of complexes bound with PGH2 has been reported. Hence, understanding the interactions of PGH2 and characterizing its binding sites in these synthases is crucial for developing novel therapeutics based on these proteins as targets. RESULTS Shape and physico-chemical properties of the PGH2 binding sites of the four prostanoid synthases were analyzed and compared in order to understand the molecular basis of the specificity. This study provides models with predicted pockets for the binding of PGH2 with PGD, PGE, PGF and PGI Synthases. The results closely match with available experimental data. The comparison showed seven physico-chemical features that are common to the four PGH2 binding sites. However this common pattern is not statistically unique and is not specific enough to distinguish between proteins that can or cannot bind PGH2. A large scale search in ASTRAL data bank, a non redundant Protein Data Bank, for a similar pattern showed the uniqueness of each of the PGH2 binding site in these Synthases. CONCLUSION The binding pockets in PGDS, PGES, PGFS and PGIS are unique and do not share significant commonality which can be characterized as a PGH2 binding site. Local comparison of these protein structures highlights a case of convergent evolution in analogous functional sites.
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30
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Genome wide analysis and comparative docking studies of new diaryl furan derivatives against human cyclooxygenase-2, lipoxygenase, thromboxane synthase and prostacyclin synthase enzymes involved in inflammatory pathway. J Mol Graph Model 2009; 28:313-29. [DOI: 10.1016/j.jmgm.2009.08.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 08/19/2009] [Accepted: 08/20/2009] [Indexed: 11/21/2022]
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31
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On the mechanism of microsomal prostaglandin E synthase type-2--a theoretical study of endoperoxide reaction with MeS(-). Bioorg Med Chem Lett 2009; 20:338-40. [PMID: 19914067 DOI: 10.1016/j.bmcl.2009.10.100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 10/23/2009] [Accepted: 10/26/2009] [Indexed: 01/25/2023]
Abstract
The reaction pathways of deprotonation versus nucleophilic substitution involving mPGES-2 enzyme catalysis were investigated by ab initio molecular orbital theory calculations for the reaction of methylthiolate with the endoperoxide core of PGH(2) and by the combined quantum mechanical molecular mechanical methods. The calculations showed that deprotonation mechanism is energetically more favorable than the nucleophilic substitution pathway.
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32
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Buczynski MW, Dumlao DS, Dennis EA. Thematic Review Series: Proteomics. An integrated omics analysis of eicosanoid biology. J Lipid Res 2009; 50:1015-38. [PMID: 19244215 PMCID: PMC2681385 DOI: 10.1194/jlr.r900004-jlr200] [Citation(s) in RCA: 400] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 02/23/2009] [Indexed: 11/20/2022] Open
Abstract
Eicosanoids have been implicated in a vast number of devastating inflammatory conditions, including arthritis, atherosclerosis, pain, and cancer. Currently, over a hundred different eicosanoids have been identified, with many having potent bioactive signaling capacity. These lipid metabolites are synthesized de novo by at least 50 unique enzymes, many of which have been cloned and characterized. Due to the extensive characterization of eicosanoid biosynthetic pathways, this field provides a unique framework for integrating genomics, proteomics, and metabolomics toward the investigation of disease pathology. To facilitate a concerted systems biology approach, this review outlines the proteins implicated in eicosanoid biosynthesis and signaling in human, mouse, and rat. Applications of the extensive genomic and lipidomic research to date illustrate the questions in eicosanoid signaling that could be uniquely addressed by a thorough analysis of the entire eicosanoid proteome.
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Affiliation(s)
| | | | - Edward A. Dennis
- Department of Chemistry and Biochemistry, Department of Pharmacology, and School of Medicine, University of California, San Diego, La Jolla, CA 92093
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33
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Brodhun F, Göbel C, Hornung E, Feussner I. Identification of PpoA from Aspergillus nidulans as a fusion protein of a fatty acid heme dioxygenase/peroxidase and a cytochrome P450. J Biol Chem 2009; 284:11792-805. [PMID: 19286665 PMCID: PMC2673248 DOI: 10.1074/jbc.m809152200] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 03/09/2009] [Indexed: 11/06/2022] Open
Abstract
The homothallic ascomycete Aspergillus nidulans serves as model organism for filamentous fungi because of its ability to propagate with both asexual and sexual life cycles, and fatty acid-derived substances regulate the balance between both cycles. These so-called psi (precocious sexual inducer) factors are produced by psi factor-producing oxygenases (Ppo enzymes). Bioinformatic analysis predicted the presence of two different heme domains in Ppo proteins: in the N-terminal region, a fatty acid heme dioxygenase/peroxidase domain is predicted, whereas in the C-terminal region, a P450 heme thiolate domain is predicted. To analyze the reaction catalyzed by Ppo enzymes, PpoA was expressed in Escherichia coli as an active enzyme. The protein was purified by 62-fold and identified as a homotetrameric ferric heme protein that metabolizes mono- as well as polyunsaturated C(16) and C(18) fatty acids at pH approximately 7.25. The presence of thiolate-ligated heme was confirmed on the basis of sequence alignments and the appearance of a characteristic 450 nm CO-binding spectrum. Studies on its reaction mechanism revealed that PpoA uses different heme domains to catalyze two separate reactions. Within the heme peroxidase domain, linoleic acid is oxidized to (8R)-hydroperoxyoctadecadienoic acid by abstracting a H-atom from C-8 of the fatty acid, yielding a carbon-centered radical that reacts with molecular dioxygen. In the second reaction step, 8-hydroperoxyoctadecadienoic acid is isomerized within the P450 heme thiolate domain to 5,8-dihydroxyoctadecadienoic acid. We identify PpoA as a bifunctional P450 fusion protein that uses a previously unknown reaction mechanism for forming psi factors.
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Affiliation(s)
- Florian Brodhun
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Science, Georg-August-University, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
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Mohamed ME, Lazarus CM. Prostanoid production inSaccharomyces cerevisiaeprovides a novel assay for nonsteroidal anti-inflammatory drugs. FEMS Yeast Res 2009; 9:420-7. [DOI: 10.1111/j.1567-1364.2008.00477.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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35
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Yanai T, Mori S. Density Functional Studies on Isomerization of Prostaglandin H2to Prostacyclin Catalyzed by Cytochrome P450. Chemistry 2009; 15:4464-73. [DOI: 10.1002/chem.200802550] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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36
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Yeh HC, Gerfen GJ, Wang JS, Tsai AL, Wang LH. Characterization of the peroxidase mechanism upon reaction of prostacyclin synthase with peracetic acid. Identification of a tyrosyl radical intermediate. Biochemistry 2009; 48:917-28. [PMID: 19187034 DOI: 10.1021/bi801382v] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Prostacyclin synthase (PGIS) is a membrane-bound class III cytochrome P450 that catalyzes an isomerization of prostaglandin H(2), an endoperoxide, to prostacyclin. We report here the characterization of the PGIS intermediates in reactions with other peroxides, peracetic acid (PA), and iodosylbenzene. Rapid-scan stopped-flow experiments revealed an intermediate with an absorption spectrum similar to that of compound ES (Cpd ES), which is an oxo-ferryl (Fe(IV)O) plus a protein-derived radical. Cpd ES, formed upon reaction with PA, has an X-band (9 GHz) EPR signal of g = 2.0047 and a half-saturation power, P(1/2), of 0.73 mW. High-field (130 GHz) EPR reveals the presence of two species of tyrosyl radicals in Cpd ES with their g-tensor components (g(x), g(y), g(z)) of 2.00970, 2.00433, 2.00211 and 2.00700, 2.00433, 2.00211 at a 1:2 ratio, indicating that one is involved in hydrogen bonding and the other is not. The line width of the g = 2 signal becomes narrower, while its P(1/2) value becomes smaller as the reaction proceeds, indicating migration of the unpaired electron to an alternative site. The rate of electron migration ( approximately 0.2 s(-1)) is similar to that of heme bleaching, suggesting the migration is associated with the enzymatic inactivation. Moreover, a g = 6 signal that is presumably a high-spin ferric species emerges after the appearance of the amino acid radical and subsequently decays at a rate comparable to that of enzymatic inactivation. This loss of the g = 6 species thus likely indicates another pathway leading to enzymatic inactivation. The inactivation, however, was prevented by the exogenous reductant guaiacol. The studies of PGIS with PA described herein provide a mechanistic model of a peroxidase reaction catalyzed by the class III cytochromes P450.
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Affiliation(s)
- Hui-Chun Yeh
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center at Houston, 6431 Fannin, Houston, Texas 77030, USA
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Yanai TK, Mori S. Density functional studies on thromboxane biosynthesis: mechanism and role of the heme-thiolate system. Chem Asian J 2009; 3:1900-11. [PMID: 18844316 DOI: 10.1002/asia.200800253] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Reaction mechanisms for the isomerization of prostaglandin H(2) to thromboxane A(2), and degradation to 12-L-hydroxy-5,8,10-heptadecatrienoic acid (HHT) and malondialdehyde (MDA), catalyzed by thromboxane synthase, were investigated using the unrestricted Becke-three-parameter plus Lee-Yang-Parr (UB3LYP) density functional level theory. In addition to the reaction pathway through Fe(IV)-porphyrin intermediates, a new reaction pathway through Fe(III)-porphyrin pi-cation radical intermediates was found. Both reactions proceed with the homolytic cleavage of endoperoxide O-O to give an alkoxy radical. This intermediate converts into an allyl radical intermediate by a C-C homolytic cleavage, followed by the formation of thromboxane A(2) having a 6-membered ring through a one electron transfer, or the degradation into HHT and MDA. The proposed mechanism shows that an iron(III)-containing system having electron acceptor ability is essential for the 6-membered ring formation leading to thromboxane A(2). Our results suggest that the step of the endoperoxide O-O homolytic bond cleavage has the highest activation energy following the binding of prostaglandin H(2) to thromboxane synthase.
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Affiliation(s)
- Tetsuya K Yanai
- Faculty of Science, Ibaraki University, Bunkyo, Mito 310-8512, Japan
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Modes of heme binding and substrate access for cytochrome P450 CYP74A revealed by crystal structures of allene oxide synthase. Proc Natl Acad Sci U S A 2008; 105:13883-8. [PMID: 18787124 DOI: 10.1073/pnas.0804099105] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cytochrome P450s exist ubiquitously in all organisms and are involved in many biological processes. Allene oxide synthase (AOS) is a P450 enzyme that plays a key role in the biosynthesis of oxylipin jasmonates, which are involved in signal and defense reactions in higher plants. The crystal structures of guayule (Parthenium argentatum) AOS (CYP74A2) and its complex with the substrate analog 13(S)-hydroxyoctadeca-9Z,11E-dienoic acid have been determined. The structures exhibit a classic P450 fold but possess a heme-binding mode with an unusually long heme binding loop and a unique I-helix. The structures also reveal two channels through which substrate and product may access and leave the active site. The entrances are defined by a loop between beta3-2 and beta3-3. Asn-276 in the substrate binding site may interact with the substrate's hydroperoxy group and play an important role in catalysis, and Lys-282 at the entrance may control substrate access and binding. These studies provide both structural insights into AOS and related P450s and a structural basis to understand the distinct reaction mechanism.
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Chang Z, Li L, Pan Z, Wang X. Crystallization and preliminary X-ray analysis of allene oxide synthase, cytochrome P450 CYP74A2, from Parthenium argentatum. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:668-70. [PMID: 18607105 PMCID: PMC2443977 DOI: 10.1107/s1744309108017545] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2008] [Accepted: 06/10/2008] [Indexed: 11/11/2022]
Abstract
Oxylipins are oxygenated derivatives of fatty acids and pivotal signaling molecules in plants and animals. Allene oxide synthase (AOS) is a key cytochrome P450 CYP74 enzyme involved in the biosynthesis of plant oxylipin jasmonates to convert 13(S)-hydroperoxide to allene oxide. Guayule (Parthenium argentatum) AOS, CYP74A2, was expressed in Escherichia coli. Protein was purified using affinity chromatography and size exclusion chromatography, and then crystallized. Two different crystal forms were obtained from 0.2 M (NH(4))H(2)PO(4), 50% MPD, 0.1 M Tris, pH 8.5 at 277 K using the hanging-drop vapor-diffusion method. Preliminary X-ray analysis was carried out, and the crystals were found to belong to the tetragonal space group I422 with cell parameters a = b = 126.5, c = 163.9 A, and the monoclinic space group C2 with cell parameters a = 336.5, b = 184.2, c = 159.0 A, beta = 118.6 degrees . Diffraction data were collected to 2.4 A resolution from a tetragonal form of crystal using a home X-ray source.
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Affiliation(s)
- Zhenzhan Chang
- Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA
| | - Lenong Li
- Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA
| | - Zhiqiang Pan
- USDA, ARS, Natural Products Utilization Research Unit, PO Box 8048, University, MS 38677, USA
| | - Xiaoqiang Wang
- Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA
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40
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Seliškar M, Košir R, Rozman D. Expression of microsomal lanosterol 14α-demethylase (CYP51) in an engineered soluble monomeric form. Biochem Biophys Res Commun 2008; 371:855-9. [DOI: 10.1016/j.bbrc.2008.04.157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Accepted: 04/29/2008] [Indexed: 11/29/2022]
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Yeh HC, Hsu PY, Tsai AL, Wang LH. Spectroscopic characterization of the oxyferrous complex of prostacyclin synthase in solution and in trapped sol-gel matrix. FEBS J 2008; 275:2305-14. [PMID: 18397321 DOI: 10.1111/j.1742-4658.2008.06385.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Prostacyclin synthase (PGIS) is a member of the cytochrome P450 family in which the oxyferrous complexes are generally labile in the absence of substrate. At 4 degrees C, the on-rate constants and off-rate constants of oxygen binding to PGIS in solution are 5.9 x 10(5) m(-1).s(-1) and 29 s(-1), respectively. The oxyferrous complex decays to a ferric form at a rate of 12 s(-1). We report, for the first time, a stable oxyferrous complex of PGIS in a transparent sol-gel monolith. The encapsulated ferric PGIS retained the same spectroscopic features as in solution. The binding capabilities of the encapsulated PGIS were demonstrated by spectral changes upon the addition of O-based, N-based and C-based ligands. The peroxidase activity of PGIS in sol-gel was three orders of magnitude slower than that in solution owing to the restricted diffusion of the substrate in sol-gel. The oxyferrous complex in sol-gel was observable for 24 h at room temperature and displayed a much red-shifted Soret peak. Stabilization of the ferrous-carbon monoxide complex in sol-gel was observed as an enrichment of the 450-nm species over the 420-nm species. This result suggests that the sol-gel method may be applied to other P450s to generate a stable intermediate in the di-oxygen activation.
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Affiliation(s)
- Hui-Chun Yeh
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center, Houston, TX 77030, USA
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Li YC, Chiang CW, Yeh HC, Hsu PY, Whitby FG, Wang LH, Chan NL. Structures of prostacyclin synthase and its complexes with substrate analog and inhibitor reveal a ligand-specific heme conformation change. J Biol Chem 2008; 283:2917-26. [PMID: 18032380 PMCID: PMC2293295 DOI: 10.1074/jbc.m707470200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Prostacyclin synthase (PGIS) is a cytochrome P450 (P450) enzyme that catalyzes production of prostacyclin from prostaglandin H(2). PGIS is unusual in that it catalyzes an isomerization rather than a monooxygenation, which is typical of P450 enzymes. To understand the structural basis for prostacyclin biosynthesis in greater detail, we have determined the crystal structures of ligand-free, inhibitor (minoxidil)-bound and substrate analog U51605-bound PGIS. These structures demonstrate a stereo-specific substrate binding and suggest features of the enzyme that facilitate isomerization. Unlike most microsomal P450s, where large substrate-induced conformational changes take place at the distal side of the heme, conformational changes in PGIS are observed at the proximal side and in the heme itself. The conserved and extensive heme propionate-protein interactions seen in all other P450s, which are largely absent in the ligand-free PGIS, are recovered upon U51605 binding accompanied by water exclusion from the active site. In contrast, when minoxidil binds, the propionate-protein interactions are not recovered and water molecules are largely retained. These findings suggest that PGIS represents a divergent evolution of the P450 family, in which a heme barrier has evolved to ensure strict binding specificity for prostaglandin H(2), leading to a radical-mediated isomerization with high product fidelity. The U51605-bound structure also provides a view of the substrate entrance and product exit channels.
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Affiliation(s)
- Yi-Ching Li
- Institute of Biochemistry, College of Life Sciences, National Chung Hsing University, Taichung City 402, Taiwan
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Ruan KH, Wu J, Cervantes V. Characterization of the Substrate Mimic Bound to Engineered Prostacyclin Synthase in Solution Using High-Resolution NMR Spectroscopy and Mutagenesis: Implication of the Molecular Mechanism in Biosynthesis of Prostacyclin. Biochemistry 2007; 47:680-8. [DOI: 10.1021/bi701671q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ke-He Ruan
- The Center for Experimental Therapeutics and PharmacoInformatics and Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas 77204
| | - Jiaxin Wu
- The Center for Experimental Therapeutics and PharmacoInformatics and Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas 77204
| | - Vanessa Cervantes
- The Center for Experimental Therapeutics and PharmacoInformatics and Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas 77204
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Lafite P, André F, Zeldin DC, Dansette PM, Mansuy D. Unusual regioselectivity and active site topology of human cytochrome P450 2J2. Biochemistry 2007; 46:10237-47. [PMID: 17705402 PMCID: PMC2377029 DOI: 10.1021/bi700876a] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The oxidation of six derivatives of terfenadone by recombinant human CYP2J2 (CYP = cytochrome P450) was studied by high-performance liquid chromatography coupled to mass spectrometry (MS) using tandem MS techniques and by 1H NMR spectroscopy. CYP2J2 exhibited a surprising regioselectivity in favor of the hydroxylation of the substrate terminal chain at the weakly reactive homobenzylic position. In contrast, hydroxylation of the same substrates by CYP3A4 mainly occurred on the most chemically reactive sites of the substrates (N-oxidation and benzylic hydroxylation). A 3D homology model of CYP2J2 was constructed using recently published structures of CYP2A6, CYP2B4, CYP2C8, CYP2C9, and CYP2D6 as templates. In contrast with other CYP2 structures, it revealed an active site cavity with a severely restricted access of substrates to the heme through a narrow hydrophobic channel. Dynamic docking of terfenadone derivatives in the CYP2J2 active site allowed one to interpret the unexpected regioselectivity of the hydroxylation of these substrates by CYP2J2, which is mainly based on this restricted access to the iron. The structural features that have been found to be important for recognition of substrates or inhibitors by CYP2J2 were also interpreted on the basis of CYP2J2-substrate interactions in this model.
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Affiliation(s)
- Pierre Lafite
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, CNRS UMR 8601, Université Paris Descartes, 45 Rue des Saints Pères, 75270 Paris Cedex 06, France
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45
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Lepesheva GI, Seliskar M, Knutson CG, Stourman NV, Rozman D, Waterman MR. Conformational dynamics in the F/G segment of CYP51 from Mycobacterium tuberculosis monitored by FRET. Arch Biochem Biophys 2007; 464:221-7. [PMID: 17585868 PMCID: PMC3042880 DOI: 10.1016/j.abb.2007.05.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 05/21/2007] [Accepted: 05/22/2007] [Indexed: 11/28/2022]
Abstract
A cysteine was introduced into the FG-loop (P187C) of CYP51 from Mycobacterium tuberculosis (MT) for selective labeling with BODIPY and fluorescence energy transfer (FRET) analysis. Förster radius for the BODIPY-heme pair was calculated assuming that the distance between the heme and Cys187 in solution corresponds to that in the crystal structure of ligand free MTCYP51. Interaction of MTCYP51 with azole inhibitors ketoconazole and fluconazole or the substrate analog estriol did not influence the fluorescence, but titration with the substrate lanosterol quenched BODIPY emission, the effect being proportional to the portion of substrate bound MTCYP51. The detected changes correspond to approximately 10A decrease in the calculated distance between BODIPY-Cys187 and the heme. The results confirm (1) functional importance of conformational motions in the MTCYP51 F/G segment and (2) applicability of FRET to monitor them in solution.
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Affiliation(s)
- Galina I. Lepesheva
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232-0146, USA
| | - Matej Seliskar
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Charles G. Knutson
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232-0146, USA
| | - Nina V. Stourman
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232-0146, USA
| | - Damjana Rozman
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Michael R. Waterman
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232-0146, USA
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46
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Yeh HC, Tsai AL, Wang LH. Reaction mechanisms of 15-hydroperoxyeicosatetraenoic acid catalyzed by human prostacyclin and thromboxane synthases. Arch Biochem Biophys 2007; 461:159-68. [PMID: 17459323 PMCID: PMC2041921 DOI: 10.1016/j.abb.2007.03.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 03/17/2007] [Accepted: 03/20/2007] [Indexed: 11/19/2022]
Abstract
Prostacyclin synthase (PGIS) and thromboxane synthase (TXAS) are atypical cytochrome P450s. They do not require NADPH or dioxygen for isomerization of prostaglandin H(2) (PGH(2)) to produce prostacyclin (PGI(2)) and thromboxane A(2) (TXA(2)). PGI(2) and TXA(2) have opposing actions on platelet aggregation and blood vessel tone. In this report, we use a lipid hydroperoxide, 15-hydroperoxyeicosatetraenoic acid (15-HPETE), to explore the active site characteristics of PGIS and TXAS. The two enzymes transformed 15-HPETE not only into 13-hydroxy-14,15-epoxy-5,8,11-eicosatrienoic acid (13-OH-14,15-EET), like many microsomal P450s, but also to 15-ketoeicosatetraenoic acid (15-KETE) and 15-hydroxyeicosatetraenoic acid (15-HETE). 13-OH-14,15-EET and 15-KETE result from homolytic cleavage of the O-O bond, whereas 15-HETE results from heterolytic cleavage, a common peroxidase pathway. About 80% of 15-HPETE was homolytically cleaved by PGIS and 60% was homolytically cleaved by TXAS. The V(max) of homolytic cleavage is 3.5-fold faster than heterolytic cleavage for PGIS-catalyzed reactions (1100 min(-1)vs. 320 min(-1)) and 1.4-fold faster for TXAS (170 min(-1)vs. 120 min(-1)). Similar K(M) values for homolytic and heterolytic cleavages were found for PGIS ( approximately 60 microM 15-HPETE) and TXAS ( approximately 80 microM 15-HPETE), making PGIS a more efficient catalyst for the 15-HPETE reaction.
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Affiliation(s)
- Hui-Chun Yeh
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center, 6431 Fannin, Houston, TX 77030, USA
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47
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Munro AW, Girvan HM, McLean KJ. Variations on a (t)heme—novel mechanisms, redox partners and catalytic functions in the cytochrome P450 superfamily. Nat Prod Rep 2007; 24:585-609. [PMID: 17534532 DOI: 10.1039/b604190f] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Andrew W Munro
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.
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