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Chmiel JA, Stuivenberg GA, Al KF, Akouris PP, Razvi H, Burton JP, Bjazevic J. Vitamins as regulators of calcium-containing kidney stones - new perspectives on the role of the gut microbiome. Nat Rev Urol 2023; 20:615-637. [PMID: 37161031 PMCID: PMC10169205 DOI: 10.1038/s41585-023-00768-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2023] [Indexed: 05/11/2023]
Abstract
Calcium-based kidney stone disease is a highly prevalent and morbid condition, with an often complicated and multifactorial aetiology. An abundance of research on the role of specific vitamins (B6, C and D) in stone formation exists, but no consensus has been reached on how these vitamins influence stone disease. As a consequence of emerging research on the role of the gut microbiota in urolithiasis, previous notions on the contribution of these vitamins to urolithiasis are being reconsidered in the field, and investigation into previously overlooked vitamins (A, E and K) was expanded. Understanding how the microbiota influences host vitamin regulation could help to determine the role of vitamins in stone disease.
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Affiliation(s)
- John A Chmiel
- Department of Microbiology & Immunology, Western University, London, Ontario, Canada
- Canadian Centre for Human Microbiome and Probiotic Research, London, Ontario, Canada
| | - Gerrit A Stuivenberg
- Department of Microbiology & Immunology, Western University, London, Ontario, Canada
- Canadian Centre for Human Microbiome and Probiotic Research, London, Ontario, Canada
| | - Kait F Al
- Department of Microbiology & Immunology, Western University, London, Ontario, Canada
- Canadian Centre for Human Microbiome and Probiotic Research, London, Ontario, Canada
| | - Polycronis P Akouris
- Department of Microbiology & Immunology, Western University, London, Ontario, Canada
- Canadian Centre for Human Microbiome and Probiotic Research, London, Ontario, Canada
| | - Hassan Razvi
- Division of Urology, Department of Surgery, Western University, London, Ontario, Canada
| | - Jeremy P Burton
- Department of Microbiology & Immunology, Western University, London, Ontario, Canada
- Canadian Centre for Human Microbiome and Probiotic Research, London, Ontario, Canada
- Division of Urology, Department of Surgery, Western University, London, Ontario, Canada
| | - Jennifer Bjazevic
- Division of Urology, Department of Surgery, Western University, London, Ontario, Canada.
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2
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Singh N, Fatima A, Singh M, kumar M, Verma I, Muthu S, Siddiqui N, Javed S. Exploration of experimental, theoretical, Hirshfeld surface, molecular docking and electronic excitation studies of Menadione: A potent anti-cancer agent. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118670] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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3
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Kraler S, Blaser MC, Aikawa E, Camici GG, Lüscher TF. Calcific aortic valve disease: from molecular and cellular mechanisms to medical therapy. Eur Heart J 2021; 43:683-697. [PMID: 34849696 DOI: 10.1093/eurheartj/ehab757] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 09/12/2021] [Accepted: 10/20/2021] [Indexed: 12/12/2022] Open
Abstract
Calcific aortic valve disease (CAVD) is a highly prevalent condition that comprises a disease continuum, ranging from microscopic changes to profound fibro-calcific leaflet remodelling, culminating in aortic stenosis, heart failure, and ultimately premature death. Traditional risk factors, such as hypercholesterolaemia and (systolic) hypertension, are shared among atherosclerotic cardiovascular disease and CAVD, yet the molecular and cellular mechanisms differ markedly. Statin-induced low-density lipoprotein cholesterol lowering, a remedy highly effective for secondary prevention of atherosclerotic cardiovascular disease, consistently failed to impact CAVD progression or to improve patient outcomes. However, recently completed phase II trials provide hope that pharmaceutical tactics directed at other targets implicated in CAVD pathogenesis offer an avenue to alter the course of the disease non-invasively. Herein, we delineate key players of CAVD pathobiology, outline mechanisms that entail compromised endothelial barrier function, and promote lipid homing, immune-cell infiltration, and deranged phospho-calcium metabolism that collectively perpetuate a pro-inflammatory/pro-osteogenic milieu in which valvular interstitial cells increasingly adopt myofibro-/osteoblast-like properties, thereby fostering fibro-calcific leaflet remodelling and eventually resulting in left ventricular outflow obstruction. We provide a glimpse into the most promising targets on the horizon, including lipoprotein(a), mineral-binding matrix Gla protein, soluble guanylate cyclase, dipeptidyl peptidase-4 as well as candidates involved in regulating phospho-calcium metabolism and valvular angiotensin II synthesis and ultimately discuss their potential for a future therapy of this insidious disease.
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Affiliation(s)
- Simon Kraler
- Center for Molecular Cardiology, University of Zurich, Wagistrasse 12, 8952 Schlieren, Switzerland.,University Heart Center, Department of Cardiology, University Hospital, Rämistrasse 100, 8091 Zurich, Switzerland
| | - Mark C Blaser
- Center for Interdisciplinary Cardiovascular Sciences, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 3 Blackfan Street, Boston, MA 02115, USA
| | - Elena Aikawa
- Center for Interdisciplinary Cardiovascular Sciences, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 3 Blackfan Street, Boston, MA 02115, USA.,Center for Excellence in Vascular Biology, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 77 Ave Louis Pasteur, NRB7, Boston, MA 02115, USA
| | - Giovanni G Camici
- Center for Molecular Cardiology, University of Zurich, Wagistrasse 12, 8952 Schlieren, Switzerland.,University Heart Center, Department of Cardiology, University Hospital, Rämistrasse 100, 8091 Zurich, Switzerland.,Department of Research and Education, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
| | - Thomas F Lüscher
- Center for Molecular Cardiology, University of Zurich, Wagistrasse 12, 8952 Schlieren, Switzerland.,Heart Division, Royal Brompton & Harefield Hospitals, Sydney Street, London SW3 6NP, UK.,National Heart and Lung Institute, Imperial College, Guy Scadding Building, Dovehouse Street, London SW3 6LY, UK
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4
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Bäck M, Michel JB. From organic and inorganic phosphates to valvular and vascular calcifications. Cardiovasc Res 2021; 117:2016-2029. [PMID: 33576771 PMCID: PMC8318101 DOI: 10.1093/cvr/cvab038] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 11/26/2020] [Accepted: 02/03/2021] [Indexed: 02/06/2023] Open
Abstract
Calcification of the arterial wall and valves is an important part of the pathophysiological process of peripheral and coronary atherosclerosis, aortic stenosis, ageing, diabetes, and chronic kidney disease. This review aims to better understand how extracellular phosphates and their ability to be retained as calcium phosphates on the extracellular matrix initiate the mineralization process of arteries and valves. In this context, the physiological process of bone mineralization remains a human model for pathological soft tissue mineralization. Soluble (ionized) calcium precipitation occurs on extracellular phosphates; either with inorganic or on exposed organic phosphates. Organic phosphates are classified as either structural (phospholipids, nucleic acids) or energetic (corresponding to phosphoryl transfer activities). Extracellular phosphates promote a phenotypic shift in vascular smooth muscle and valvular interstitial cells towards an osteoblast gene expression pattern, which provokes the active phase of mineralization. A line of defense systems protects arterial and valvular tissue calcifications. Given the major roles of phosphate in soft tissue calcification, phosphate mimetics, and/or prevention of phosphate dissipation represent novel potential therapeutic approaches for arterial and valvular calcification.
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Affiliation(s)
- Magnus Bäck
- Division of Valvular and Coronary Disease, Department of Cardiology, Karolinska University Hospital, 141 86 Stockholm, Sweden.,Department of Medicine, Karolinska Institutet, Stockholm, Sweden.,University of Lorraine, Nancy University Hospital, INSERM U1116, Nancy, France
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5
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Feyissa Q, Xu F, Ibrahim Z, Li Y, Xu KL, Guo Z, Ahmad J, Vostal JG. Synergistic bactericidal effects of pairs of photosensitizer molecules activated by ultraviolet A light against bacteria in plasma. Transfusion 2020; 61:594-602. [PMID: 33219568 DOI: 10.1111/trf.16180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 10/12/2020] [Accepted: 10/12/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND The current approach to reducing bacterial contamination in blood transfusion products is through detection or pathogen reduction methods, some of which utilize ultraviolet (UV) light photosensitizers. A small number of photosensitizers are being used as single agents in combination with UV light, but their efficacy can be limited against some pathogens. Benzophenone (BP) and vitamins B1, B6, and K3 have been identified as effective UVA photosensitizers for inactivation of bacteria. We evaluated whether combining pairs of photosensitizers in this group would have synergistic bactericidal effects on Gram-negative and Gram-positive bacteria. STUDY DESIGN AND METHODS Bacteria species of Escherichia coli, Bacillus cereus, Staphylococcus aureus, and Klebsiella pneumoniae were mixed with 0 to 100 mM concentrations of photosensitizers and exposed to UVA irradiation at 18 J/cm2 to assess their bactericidal effects. RESULTS Single photosensitizers irradiated with UVA produced a range of bactericidal activity. When combined in pairs, all demonstrated some synergistic bactericidal effects with up to 4-log reduction above the sum of activities of individual molecules in the pair against bacteria in plasma. Photosensitizer pairs with BP had the highest synergism across all bacteria. With vitamin K3 in the pair, synergism was evident for Gram-positive but not for Gram-negative bacteria. Vitamin B1 and vitamin B6 had the least synergism. These results indicate that a combination approach with multiple photosensitizers may extend effectiveness of pathogen reduction in plasma. CONCLUSIONS Combining photosensitizers in pathogen reduction methods could improve bactericidal efficacy and lead to use of lower concentrations of photosensitizers to reduce toxicities and unwanted side effects.
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Affiliation(s)
- Qinati Feyissa
- Laboratory of Cellular Hematology, Division of Blood Components and Devices, CBER, FDA, Silver Spring, Maryland
| | - Fei Xu
- Laboratory of Cellular Hematology, Division of Blood Components and Devices, CBER, FDA, Silver Spring, Maryland
| | - Zina Ibrahim
- Laboratory of Cellular Hematology, Division of Blood Components and Devices, CBER, FDA, Silver Spring, Maryland
| | - Ying Li
- Laboratory of Cellular Hematology, Division of Blood Components and Devices, CBER, FDA, Silver Spring, Maryland
| | - Kevin L Xu
- Laboratory of Cellular Hematology, Division of Blood Components and Devices, CBER, FDA, Silver Spring, Maryland
| | - Zihan Guo
- Laboratory of Cellular Hematology, Division of Blood Components and Devices, CBER, FDA, Silver Spring, Maryland
| | - Justen Ahmad
- Laboratory of Cellular Hematology, Division of Blood Components and Devices, CBER, FDA, Silver Spring, Maryland
| | - Jaroslav G Vostal
- Laboratory of Cellular Hematology, Division of Blood Components and Devices, CBER, FDA, Silver Spring, Maryland
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6
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Caprioglio D, Mattoteia D, Pollastro F, Negri R, Lopatriello A, Chianese G, Minassi A, Collado JA, Munoz E, Taglialatela-Scafati O, Appendino G. The Oxidation of Phytocannabinoids to Cannabinoquinoids. J Nat Prod 2020; 83:1711-1715. [PMID: 32315173 PMCID: PMC7997633 DOI: 10.1021/acs.jnatprod.9b01284] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Spurred by a growing interest in cannabidiolquinone (CBDQ, HU-313, 2) as a degradation marker and alledged hepatotoxic metabolite of cannabidiol (CBD, 1), we performed a systematic study on the oxidation of CBD (1) to CBDQ (2) under a variety of experimental conditions (base-catalyzed aerobic oxidation, oxidation with metals, oxidation with hypervalent iodine reagents). The best results in terms of reproducibility and scalability were obtained with λ5-periodinanes (Dess-Martin periodinane, 1-hydroxy-1λ5,2-benziodoxole-1,3-dione (IBX), and SIBX, a stabilized, nonexplosive version of IBX). With these reagents, the oxidative dimerization that plagues the reaction under basic aerobic conditions was completely suppressed. A different reaction course was observed with the copper(II) chloride-hydroxylamine complex (Takehira reagent), which afforded a mixture of the hydroxyiminodienone 11 and the halogenated resorcinol 12. The λ5-periodinane oxidation was general for phytocannabinoids, turning cannabigerol (CBG, 18), cannabichromene (CBC, 10), and cannabinol (CBN, 19) into their corresponding hydroxyquinones (20, 21, and 22, respectively). All cannabinoquinoids modulated to a various extent peroxisome proliferator-activated receptor gamma (PPAR-γ) activity, outperforming their parent resorcinols in terms of potency, but the iminoquinone 11, the quinone dimers 3 and 23, and the haloresorcinol 12 were inactive, suggesting a specific role for the monomeric hydroxyquinone moiety in the interaction with PPAR-γ.
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Affiliation(s)
- Diego Caprioglio
- Dipartimento
di Scienze del Farmaco, Università
del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Daiana Mattoteia
- Dipartimento
di Scienze del Farmaco, Università
del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Federica Pollastro
- Dipartimento
di Scienze del Farmaco, Università
del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Roberto Negri
- Dipartimento
di Scienze del Farmaco, Università
del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Annalisa Lopatriello
- Dipartimento
di Farmacia, Università di Napoli
Federico II, Via Montesano 49, 80131 Napoli, Italy
| | - Giuseppina Chianese
- Dipartimento
di Farmacia, Università di Napoli
Federico II, Via Montesano 49, 80131 Napoli, Italy
| | - Alberto Minassi
- Dipartimento
di Scienze del Farmaco, Università
del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Juan A. Collado
- Maimonides
Biomedical Research Institute of Córdoba; Department of Cellular
Biology, Physiology and Immunology, University
of Córdoba; University Hospital Reina Sofía, Avenida de Menendez Pidal s/n, 14004 Cordoba, Spain
| | - Eduardo Munoz
- Maimonides
Biomedical Research Institute of Córdoba; Department of Cellular
Biology, Physiology and Immunology, University
of Córdoba; University Hospital Reina Sofía, Avenida de Menendez Pidal s/n, 14004 Cordoba, Spain
| | - Orazio Taglialatela-Scafati
- Dipartimento
di Farmacia, Università di Napoli
Federico II, Via Montesano 49, 80131 Napoli, Italy
- Phone: +39-081-678509. Fax: +39-081678552. (O.T.-S.)
| | - Giovanni Appendino
- Dipartimento
di Scienze del Farmaco, Università
del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
- Phone: +39-0321-375744. Fax: +39-0321375744. Email address: (G.A.)
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7
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Yu Y, Gao X, Zang Z, Xu L, Liu G. Solid-liquid equilibrium for the ternary 2-naphthaldehyde + 2-methyl-1,4-naphthoquinone + ethanol system: Determination, correlation and molecular simulation. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.03.104] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Joshi S, Fedoseyenko D, Mahanta N, Ducati RG, Feng M, Schramm VL, Begley TP. Antibacterial Strategy against H. pylori: Inhibition of the Radical SAM Enzyme MqnE in Menaquinone Biosynthesis. ACS Med Chem Lett 2019; 10:363-366. [PMID: 30891141 PMCID: PMC6421580 DOI: 10.1021/acsmedchemlett.8b00649] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 02/15/2019] [Indexed: 12/13/2022] Open
Abstract
Aminofutalosine synthase (MqnE) catalyzes an important rearrangement reaction in menaquinone biosynthesis by the futalosine pathway. In this Letter, we report the identification of previously unreported inhibitors of MqnE using a mechanism-guided approach. The best inhibitor shows efficient inhibitory activity against H. pylori (IC50 = 1.8 ± 0.4 μM) and identifies MqnE as a promising target for antibiotic development.
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Affiliation(s)
- Sumedh Joshi
- Department
of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Dmytro Fedoseyenko
- Department
of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Nilkamal Mahanta
- Department
of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Rodrigo G. Ducati
- Department
of Biochemistry, Albert Einstein College
of Medicine, Bronx, New York 10461, United States
| | - Mu Feng
- Department
of Biochemistry, Albert Einstein College
of Medicine, Bronx, New York 10461, United States
| | - Vern L. Schramm
- Department
of Biochemistry, Albert Einstein College
of Medicine, Bronx, New York 10461, United States
| | - Tadhg P. Begley
- Department
of Chemistry, Texas A&M University, College Station, Texas 77842, United States
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9
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Joshi S, Fedoseyenko D, Mahanta N, Manion H, Naseem S, Dairi T, Begley TP. Novel enzymology in futalosine-dependent menaquinone biosynthesis. Curr Opin Chem Biol 2018; 47:134-41. [DOI: 10.1016/j.cbpa.2018.09.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 09/13/2018] [Accepted: 09/20/2018] [Indexed: 12/12/2022]
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10
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Law BJC, Zhuo Y, Winn M, Francis D, Zhang Y, Samborskyy M, Murphy A, Ren L, Leadlay PF, Micklefield J. A vitamin K-dependent carboxylase orthologue is involved in antibiotic biosynthesis. Nat Catal 2018. [DOI: 10.1038/s41929-018-0178-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Peeters FECM, Dudink EAMP, Kimenai DM, Weijs B, Altintas S, Heckman LIB, Mihl C, Schurgers LJ, Wildberger JE, Meex SJR, Kietselaer BLJH, Crijns HJGM. Vitamin K Antagonists, Non-Vitamin K Antagonist Oral Anticoagulants, and Vascular Calcification in Patients with Atrial Fibrillation. TH Open 2018; 2:e391-e398. [PMID: 31249966 PMCID: PMC6524908 DOI: 10.1055/s-0038-1675578] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 09/21/2018] [Indexed: 01/07/2023] Open
Abstract
Background Vitamin K antagonists (VKAs) are associated with coronary artery calcification in low-risk populations, but their effect on calcification of large arteries remains uncertain. The effect of non-vitamin K antagonist oral anticoagulants (NOACs) on vascular calcification is unknown. We investigated the influence of use of VKA and NOAC on calcification of the aorta and aortic valve. Methods In patients with atrial fibrillation without a history of major adverse cardiac or cerebrovascular events who underwent computed tomographic angiography, the presence of ascending aorta calcification (AsAC), descending aorta calcification (DAC), and aortic valve calcification (AVC) was determined. Confounders for VKA/NOAC treatment were identified and propensity score adjusted logistic regression explored the association between treatment and calcification (Agatston score > 0). AsAC, DAC, and AVC differences were assessed in propensity score-matched groups. Results Of 236 patients (33% female, age: 58 ± 9 years), 71 (30%) used VKA (median duration: 122 weeks) and 79 (34%) used NOAC (median duration: 16 weeks). Propensity score-adjusted logistic regression revealed that use of VKA was significantly associated with AsAC (odds ratio [OR]: 2.31; 95% confidence interval [CI]: 1.16-4.59; p = 0.017) and DAC (OR: 2.38; 95% CI: 1.22-4.67; p = 0.012) and a trend in AVC (OR: 1.92; 95% CI: 0.98-3.80; p = 0.059) compared with non-anticoagulation. This association was absent in NOAC versus non-anticoagulant (AsAC OR: 0.51; 95% CI: 0.21-1.21; p = 0.127; DAC OR: 0.80; 95% CI: 0.36-1.76; p = 0.577; AVC OR: 0.62; 95% CI: 0.27-1.40; p = 0.248). A total of 178 patients were propensity score matched in three pairwise comparisons. Again, use of VKA was associated with DAC ( p = 0.043) and a trend toward more AsAC ( p = 0.059), while use of NOAC was not (AsAC p = 0.264; DAC p = 0.154; AVC p = 0.280). Conclusion This cross-sectional study shows that use of VKA seems to contribute to vascular calcification. The calcification effect was not observed in NOAC users.
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Affiliation(s)
- Frederique E C M Peeters
- Department of Cardiology, Maastricht University Medical Center+ and CARIM, Maastricht, The Netherlands
| | - Elton A M P Dudink
- Department of Cardiology, Maastricht University Medical Center+ and CARIM, Maastricht, The Netherlands
| | - Dorien M Kimenai
- Department of Clinical Chemistry, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Bob Weijs
- Department of Cardiology, Maastricht University Medical Center+ and CARIM, Maastricht, The Netherlands
| | - Sibel Altintas
- Department of Cardiology, Maastricht University Medical Center+ and CARIM, Maastricht, The Netherlands
| | - Luuk I B Heckman
- Department of Cardiology, Maastricht University Medical Center+ and CARIM, Maastricht, The Netherlands
| | - Casper Mihl
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+ and CARIM, Maastricht, The Netherlands
| | - Leon J Schurgers
- Department of Biochemistry, Maastricht University and CARIM, Maastricht, The Netherlands
| | - Joachim E Wildberger
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+ and CARIM, Maastricht, The Netherlands
| | - Steven J R Meex
- Department of Clinical Chemistry, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Bas L J H Kietselaer
- Department of Cardiology, Maastricht University Medical Center+ and CARIM, Maastricht, The Netherlands.,Department of Cardiology, Zuyderland Medical Center, Heerlen/Sittard, The Netherlands
| | - Harry J G M Crijns
- Department of Cardiology, Maastricht University Medical Center+ and CARIM, Maastricht, The Netherlands
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12
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Abstract
Vitamin K (VK) is an essential cofactor for the post-translational conversion of peptide-bound glutamate to γ-carboxyglutamate. The resultant vitamin K-dependent proteins are known or postulated to possess a variety of biological functions, chiefly in the maintenance of hemostasis. The vitamin K cycle is a cellular pathway that drives γ-carboxylation and recycling of VK via γ-carboxyglutamyl carboxylase (GGCX) and vitamin K epoxide reductase (VKOR), respectively. In this review, we show how novel molecular biological approaches are providing new insights into the pathophysiological mechanisms caused by rare mutations of both GGCX and VKOR. We also discuss how other protein regulators influence the intermediary metabolism of VK, first through intestinal absorption and second through a pathway that converts some dietary phylloquinone to menadione, which is prenylated to menaquinone-4 (MK-4) in target tissues by UBIAD1. The contribution of MK-4 synthesis to VK functions is yet to be revealed.
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Affiliation(s)
- Martin J Shearer
- Centre for Haemostasis and Thrombosis, Guy's and St Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom;
| | - Toshio Okano
- Department of Hygienic Sciences, Kobe Pharmaceutical University, Kobe 658-8558 Japan;
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13
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Boersch M, Rudrawar S, Grant G, Zunk M. Menaquinone biosynthesis inhibition: a review of advancements toward a new antibiotic mechanism. RSC Adv 2018; 8:5099-5105. [PMID: 35542397 PMCID: PMC9078190 DOI: 10.1039/c7ra12950e] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/20/2018] [Accepted: 01/22/2018] [Indexed: 11/21/2022] Open
Abstract
Menaquinone is essential in electron transport and ATP generation in all Gram-positive, and anaerobically respiring Gram-negative bacteria. Inhibition of menaquinone production at different steps of the biosynthesis pathway has shown promising novel antibacterial action.
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Affiliation(s)
- M. Boersch
- School of Pharmacy and Pharmacology
- Griffith University
- Gold Coast
- Australia
- Quality Use of Medicines Network
| | - S. Rudrawar
- School of Pharmacy and Pharmacology
- Griffith University
- Gold Coast
- Australia
- Quality Use of Medicines Network
| | - G. Grant
- School of Pharmacy and Pharmacology
- Griffith University
- Gold Coast
- Australia
- Quality Use of Medicines Network
| | - M. Zunk
- School of Pharmacy and Pharmacology
- Griffith University
- Gold Coast
- Australia
- Quality Use of Medicines Network
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14
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Abstract
A flock of Rambouillet sheep was examined because of increased lamb mortality caused by ineffective hemostasis at parturition. Neonatal-affected lambs presented with inadequate hemostasis at the umbilicus, pale mucus membranes, and markedly prolonged activated clotting time. Affected lambs had consistently prolonged 1-stage prothrombin times and activated partial thromboplastin times that supported a defect in the common pathway or defects in both the intrinsic and extrinsic pathway of the coagulation cascade. Decreased activity of vitamin K-dependent procoagulant factors II, VII, IX, and X in male and female lambs suggested either a defect of the hepatic enzyme γ-glutamyl carboxylase, or vitamin K1 2,3 epoxide reductase. Affected lamb hepatic γ-glutamyl carboxylase activity was markedly decreased compared with that of age- and sex-matched control lambs, while vitamin K1 2,3 epoxide reductase and glucose-6-phosphatase activities were similar between an affected and normal lamb. Subcutaneous vitamin K1 supplementation did not increase vitamin K-dependent procoagulant factor activities in 3 lambs administered vitamin K1 daily. These data confirm defective γ-glutamyl carboxylase activity as the cause of impaired coagulation of sheep in this flock. This flock represents the only viable animal model of hereditarily defective γ-glutamyl carboxylase activity.
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Affiliation(s)
- J S Johnson
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
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15
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Abstract
Vitamin K-dependent proteins require carboxylation of certain glutamates for their biological functions. The enzymes involved in the vitamin K-dependent carboxylation include: gamma-glutamyl carboxylase (GGCX), vitamin K epoxide reductase (VKOR) and an as-yet-unidentified vitamin K reductase (VKR). Due to the hydrophobicity of vitamin K, these enzymes are likely to be integral membrane proteins that reside in the endoplasmic reticulum. Therefore, structure-function studies on these enzymes have been challenging, and some of the results are notably controversial. Patients with naturally occurring mutations in these enzymes, who mainly exhibit bleeding disorders or are resistant to oral anticoagulant treatment, provide valuable information for the functional study of the vitamin K cycle enzymes. In this review, we discuss: (i) the discovery of the enzymatic activities and gene identifications of the vitamin K cycle enzymes; (ii) the identification of their functionally important regions and their active site residues; (iii) the membrane topology studies of GGCX and VKOR; and (iv) the controversial issues regarding the structure and function studies of these enzymes, particularly, the membrane topology, the role of the conserved cysteines and the mechanism of active site regeneration of VKOR. We also discuss the possibility that a paralogous protein of VKOR, VKOR-like 1 (VKORL1), is involved in the vitamin K cycle, and the importance of and possible approaches for identifying the unknown VKR. Overall, we describe the accomplishments and the remaining questions in regard to the structure and function studies of the enzymes in the vitamin K cycle.
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Affiliation(s)
- J-K Tie
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - D W Stafford
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Matarlo JS, Evans CE, Sharma I, Lavaud LJ, Ngo SC, Shek R, Rajashankar KR, French JB, Tan DS, Tonge PJ. Mechanism of MenE inhibition by acyl-adenylate analogues and discovery of novel antibacterial agents. Biochemistry 2015; 54:6514-6524. [PMID: 26394156 DOI: 10.1021/acs.biochem.5b00966] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
MenE is an o-succinylbenzoyl-CoA (OSB-CoA) synthetase in the bacterial menaquinone biosynthesis pathway and is a promising target for the development of novel antibacterial agents. The enzyme catalyzes CoA ligation via an acyl-adenylate intermediate, and we have previously reported tight-binding inhibitors of MenE based on stable acyl-sulfonyladenosine analogues of this intermediate, including OSB-AMS (1), which has an IC50 value of ≤25 nM for Escherichia coli MenE. Herein, we show that OSB-AMS reduces menaquinone levels in Staphylococcus aureus, consistent with its proposed mechanism of action, despite the observation that the antibacterial activity of OSB-AMS is ∼1000-fold lower than the IC50 for enzyme inhibition. To inform the synthesis of MenE inhibitors with improved antibacterial activity, we have undertaken a structure-activity relationship (SAR) study stimulated by the knowledge that OSB-AMS can adopt two isomeric forms in which the OSB side chain exists either as an open-chain keto acid or a cyclic lactol. These studies revealed that negatively charged analogues of the keto acid form bind, while neutral analogues do not, consistent with the hypothesis that the negatively charged keto acid form of OSB-AMS is the active isomer. X-ray crystallography and site-directed mutagenesis confirm the importance of a conserved arginine for binding the OSB carboxylate. Although most lactol isomers tested were inactive, a novel difluoroindanediol inhibitor (11) with improved antibacterial activity was discovered, providing a pathway toward the development of optimized MenE inhibitors in the future.
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Affiliation(s)
- Joe S Matarlo
- Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, NY 11794-3400.,Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-3400
| | - Christopher E Evans
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Indrajeet Sharma
- Chemical Biology Program and Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Lubens J Lavaud
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Stephen C Ngo
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Roger Shek
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-3400
| | - Kanagalaghatta R Rajashankar
- NE-CAT and Department of Chemistry and Chemical Biology, Building 436E, Argonne National Laboratory, Argonne, IL 60439
| | - Jarrod B French
- Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, NY 11794-3400.,Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400.,Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-3400
| | - Derek S Tan
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065.,Chemical Biology Program and Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Peter J Tonge
- Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, NY 11794-3400.,Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
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17
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Rubino FM. Toxicity of Glutathione-Binding Metals: A Review of Targets and Mechanisms. Toxics 2015; 3:20-62. [PMID: 29056650 PMCID: PMC5634692 DOI: 10.3390/toxics3010020] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/04/2014] [Accepted: 01/14/2015] [Indexed: 02/07/2023]
Abstract
Mercury, cadmium, arsenic and lead are among priority metals for toxicological studies due to the frequent human exposure and to the significant burden of disease following acute and chronic intoxication. Among their common characteristics is chemical affinity to proteins and non-protein thiols and their ability to generate cellular oxidative stress by the best-known Fenton mechanism. Their health effects are however diverse: kidney and liver damage, cancer at specific sites, irreversible neurological damages with metal-specific features. Mechanisms for the induction of oxidative stress by interaction with the cell thiolome will be presented, based on literature evidence and of experimental findings.
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Affiliation(s)
- Federico Maria Rubino
- LaTMA Laboratory for Analytical Toxicology and Metabonomics, Department of Health Sciences, Università degli Studi di Milano at "Ospedale San Paolo" v. A. di Rudinì 8, I-20142 Milano, Italy.
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18
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Abstract
The topic of "Vitamin K" is currently booming on the health products market. Vitamin K is known to be important for blood coagulation. Current research increasingly indicates that the antihaemorrhagic vitamin has a considerable benefit in the prevention and treatment of bone and vascular disease. Vitamin K1 (phylloquinone) is more abundant in foods but less bioactive than the vitamin K2 menaquinones (especially MK-7, menaquinone-7). Vitamin K compounds undergo oxidation-reduction cycling within the endoplasmic reticulum membrane, donating electrons to activate specific proteins via enzymatic gamma-carboxylation of glutamate groups before being enzymatically reduced. Along with coagulation factors (II, VII, IX, X, and prothrombin), protein C and protein S, osteocalcin (OC), matrix Gla protein (MGP), periostin, Gas6, and other vitamin K-dependent (VKD) proteins support calcium homeostasis, inhibit vessel wall calcification, support endothelial integrity, facilitate bone mineralization, are involved in tissue renewal and cell growth control, and have numerous other effects. The following review describes the history of vitamin K, the physiological significance of the K vitamers, updates skeletal and cardiovascular benefits and important interactions with drugs.
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Affiliation(s)
- U Gröber
- Academy for Micronutrient Medicine ; Essen, Germany
| | - J Reichrath
- Saarland University Clinics ; Homburg/Saar, Germany
| | - M F Holick
- Boston University Medical Center ; Boston, MA USA
| | - K Kisters
- Academy for Micronutrient Medicine ; Essen, Germany ; St. Anna Hospital; Medical Clinic 1 ; Herne, Germany
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19
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Parker CH, Morgan C, Rand KD, Engen JR, Jorgenson J, Stafford DW. A conformational investigation of propeptide binding to the integral membrane protein γ-glutamyl carboxylase using nanodisc hydrogen exchange mass spectrometry. Biochemistry 2014; 53:1511-20. [PMID: 24512177 PMCID: PMC3970815 DOI: 10.1021/bi401536m] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 02/07/2014] [Indexed: 01/16/2023]
Abstract
Gamma (γ)-glutamyl carboxylase (GGCX) is an integral membrane protein responsible for the post-translational catalytic conversion of select glutamic acid (Glu) residues to γ-carboxy glutamic acid (Gla) in vitamin K-dependent (VKD) proteins. Understanding the mechanism of carboxylation and the role of GGCX in the vitamin K cycle is of biological interest in the development of therapeutics for blood coagulation disorders. Historically, biophysical investigations and structural characterizations of GGCX have been limited due to complexities involving the availability of an appropriate model membrane system. In previous work, a hydrogen exchange mass spectrometry (HX MS) platform was developed to study the structural configuration of GGCX in a near-native nanodisc phospholipid environment. Here we have applied the nanodisc-HX MS approach to characterize specific domains of GGCX that exhibit structural rearrangements upon binding the high-affinity consensus propeptide (pCon; AVFLSREQANQVLQRRRR). pCon binding was shown to be specific for monomeric GGCX-nanodiscs and promoted enhanced structural stability to the nanodisc-integrated complex while maintaining catalytic activity in the presence of carboxylation co-substrates. Noteworthy modifications in HX of GGCX were prominently observed in GGCX peptides 491-507 and 395-401 upon pCon association, consistent with regions previously identified as sites for propeptide and glutamate binding. Several additional protein regions exhibited minor gains in solvent protection upon propeptide incorporation, providing evidence for a structural reorientation of the GGCX complex in association with VKD carboxylation. The results herein demonstrate that nanodisc-HX MS can be utilized to study molecular interactions of membrane-bound enzymes in the absence of a complete three-dimensional structure and to map dynamic rearrangements induced upon ligand binding.
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Affiliation(s)
- Christine H. Parker
- Department of Chemistry and Department of
Biology, University of North Carolina at
Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Christopher
R. Morgan
- Department
of Chemistry & Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Kasper D. Rand
- Department
of Chemistry & Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - John R. Engen
- Department
of Chemistry & Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - James
W. Jorgenson
- Department of Chemistry and Department of
Biology, University of North Carolina at
Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Darrel W. Stafford
- Department of Chemistry and Department of
Biology, University of North Carolina at
Chapel Hill, Chapel Hill, North Carolina 27599, United States
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20
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Abu-Elfotoh AM, Tsuzuki K, Nguyen TB, Chanthamath S, Shibatomi K, Iwasa S. Quinones synthesis via hydrogen peroxide oxidation of dihydroxy arenes catalyzed by homogeneous and macroporous-polymer-supported ruthenium catalysts. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.07.069] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Woeckel V, van der Eerden B, Schreuders-Koedam M, Eijken M, Van Leeuwen J. 1α,25-dihydroxyvitamin D3stimulates activin A production to fine-tune osteoblast-induced mineralization. J Cell Physiol 2013; 228:2167-74. [DOI: 10.1002/jcp.24388] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 04/03/2013] [Indexed: 01/08/2023]
Affiliation(s)
- V.J. Woeckel
- Departments of Internal Medicine; Erasmus Medical Center; Rotterdam The Netherlands
| | | | - M. Schreuders-Koedam
- Departments of Internal Medicine; Erasmus Medical Center; Rotterdam The Netherlands
| | - M. Eijken
- Departments of Internal Medicine; Erasmus Medical Center; Rotterdam The Netherlands
| | - J.P.T.M. Van Leeuwen
- Departments of Internal Medicine; Erasmus Medical Center; Rotterdam The Netherlands
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22
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Affiliation(s)
| | - Wei-chen Chang
- College of Pharmacy and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Hung-wen Liu
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
- College of Pharmacy and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
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23
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Rishavy MA, Berkner KL. Vitamin K oxygenation, glutamate carboxylation, and processivity: defining the three critical facets of catalysis by the vitamin K-dependent carboxylase. Adv Nutr 2012; 3:135-48. [PMID: 22516721 PMCID: PMC3648714 DOI: 10.3945/an.111.001719] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The vitamin K-dependent carboxylase uses vitamin K oxygenation to drive carboxylation of multiple glutamates in vitamin K-dependent proteins, rendering them active in a variety of physiologies. Multiple carboxylations of proteins are required for their activity, and the carboxylase is processive, so that premature dissociation of proteins from the carboxylase does not occur. The carboxylase is unique, with no known homology to other enzyme families, and structural determinations have not been made, rendering an understanding of catalysis elusive. Although a model explaining the relationship of oxygenation to carboxylation had been developed, until recently almost nothing was known of the function of the carboxylase itself in catalysis. In the past decade, discovery and analysis of naturally occurring carboxylase mutants has led to identification of functionally relevant residues and domains. Further, identification of nonmammalian carboxylase orthologs has provided a basis for bioinformatic analysis to identify candidates for critical functional residues. Biochemical analysis of rationally chosen carboxylase mutants has led to breakthroughs in understanding vitamin K oxygenation, glutamate carboxylation, and maintenance of processivity by the carboxylase. Protein carboxylation has also been assessed in vivo, and the intracellular environment strongly affects carboxylase function. The carboxylase is an integral membrane protein, and topological analysis, coupled with biochemical determinations, suggests that interaction of the carboxylase with the membrane is an important facet of function. Carboxylase homologs, likely acquired by horizontal transfer, have been discovered in some bacteria, and functional analysis of these homologs has the potential to lead to the discovery of new roles of vitamin K in biology.
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24
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Eitzinger N, Surmann-Schmitt C, Bösl M, Schett G, Engelke K, Hess A, von der Mark K, Stock M. Ucma is not necessary for normal development of the mouse skeleton. Bone 2012; 50:670-80. [PMID: 22155508 DOI: 10.1016/j.bone.2011.11.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 11/04/2011] [Accepted: 11/09/2011] [Indexed: 01/01/2023]
Abstract
Ucma (Upper zone of growth plate and Cartilage Matrix Associated protein) is a highly conserved tyrosine-sulphated secreted protein of Mw 17 kDa, which is expressed by juvenile chondrocytes. To evaluate the physiological function of this novel cartilage protein, we generated a Ucma-deficient mouse strain by introducing a lacZ/neoR-cassette into the first exon of the Ucma gene. This mutation results in the complete loss of Ucma mRNA and protein expression. Surprisingly, however, although previous in vitro studies implied a role for Ucma in calcification and ossification, these processes were not affected in Ucma-deficient mice during normal development. Likewise, cartilage development was normal. While in previous works Ucma was mainly detected in the cartilage of embryonic and young mice, we detected Ucma expression also in the adult cartilage of the ribs using the lacZ cassette under the control of the Ucma promoter. Moreover, Ucma protein was specifically detected in adult growth plate cartilage by immunohistochemistry. Considering that skeletal development in Ucma-deficient mice is not significantly impaired, protein expression in adult cartilage indicates that Ucma might be involved in skeletal homeostasis and in the mechanical properties of the skeleton during challenging conditions such as ageing or disease.
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Affiliation(s)
- Nicole Eitzinger
- Department of Experimental Medicine I, Nikolaus-Fiebiger Centre of Molecular Medicine, University of Erlangen-Nuremberg, 91054 Erlangen, Germany
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25
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Rishavy MA, Hallgren KW, Berkner KL. The vitamin K-dependent carboxylase generates γ-carboxylated glutamates by using CO2 to facilitate glutamate deprotonation in a concerted mechanism that drives catalysis. J Biol Chem 2011; 286:44821-32. [PMID: 21896484 DOI: 10.1074/jbc.m111.249177] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The γ-glutamyl carboxylase converts Glu to carboxylated Glu (Gla) to activate a large number of vitamin K-dependent proteins with diverse functions, and this broad physiological impact makes it critical to understand the mechanism of carboxylation. Gla formation is thought to occur in two independent steps (i.e. Glu deprotonation to form a carbanion that then reacts with CO(2)), based on previous studies showing unresponsiveness of Glu deprotonation to CO(2). However, our recent studies on the kinetic properties of a variant enzyme (H160A) showing impaired Glu deprotonation prompted a reevaluation of this model. Glu deprotonation monitored by tritium release from the glutamyl γ-carbon was dependent upon CO(2), and a proportional increase in both tritium release and Gla formation occurred over a range of CO(2) concentrations. This discrepancy with the earlier studies using microsomes is probably due to the known accessibility of microsomal carboxylase to water, which reprotonates the carbanion. In contrast, tritium incorporation experiments with purified carboxylase showed very little carbanion reprotonation and consequently revealed the dependence of Glu deprotonation on CO(2). Cyanide stimulated Glu deprotonation and carbanion reprotonation to the same extent in wild type enzyme but not in the H160A variant. Glu deprotonation that depends upon CO(2) but that also occurs when water or cyanide are present strongly suggests a concerted mechanism facilitated by His-160 in which an electrophile accepts the negative charge on the developing carbanion. This revised mechanism provides important insight into how the carboxylase catalyzes the reaction by avoiding the formation of a high energy discrete carbanion.
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Affiliation(s)
- Mark A Rishavy
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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26
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Wu S, Liu S, Davis CH, Stafford DW, Kulman JD, Pedersen LG. A hetero-dimer model for concerted action of vitamin K carboxylase and vitamin K reductase in vitamin K cycle. J Theor Biol 2011; 279:143-9. [PMID: 21453708 DOI: 10.1016/j.jtbi.2011.03.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 03/23/2011] [Accepted: 03/23/2011] [Indexed: 10/18/2022]
Abstract
Vitamin K carboxylase (VKC) is believed to convert vitamin K, in the vitamin K cycle, to an alkoxide-epoxide form which then reacts with CO(2) and glutamate to generate γ-carboxyglutamic acid (Gla). Subsequently, vitamin K epoxide reductase (VKOR) is thought to convert the alkoxide-epoxide to a hydroquinone form. By recycling vitamin K, the two integral-membrane proteins, VKC and VKOR, maintain vitamin K levels and sustain the blood coagulation cascade. Unfortunately, NMR or X-ray crystal structures of the two proteins have not been characterized. Thus, our understanding of the vitamin K cycle is only partial at the molecular level. In this study, based on prior biochemical experiments on VKC and VKOR, we propose a hetero-dimeric form of VKC and VKOR that may explain the efficient oxidation and reduction of vitamin K during the vitamin K cycle.
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Affiliation(s)
- Sangwook Wu
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
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27
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Wu S, Liu S, Davis CH, Stafford DW, Pedersen LG. Quantum Chemical Study of the Mechanism of Action of Vitamin K Carboxylase in Solvent. Int J Quantum Chem 2010; 110:2744-2751. [PMID: 21892230 PMCID: PMC3164839 DOI: 10.1002/qua.22740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We investigate the post-translational generation of Gla (γ-carboxy glutamic acid) from Glu (glutamic acid) by vitamin K carboxylase (VKC) in solvent. VKC is thought to convert vitamin K, in the vitamin K cycle, to an alkoxide-epoxide form, which then reacts with CO(2) to generate an essential ingredient in blood coagulation, γ-carboxyglutamic acid (Gla). The generation of Gla from Glu is found to be exergenic (-15 kcal/mol) in aqueous solution with the SM6 method. We also produced the free energy profile for this model biochemical process with other solvent methods (polarizable continuum model, dielectric polarizable continuum model) and different dielectric constants. The biological implications are discussed.
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Affiliation(s)
- Sangwook Wu
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290
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28
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Murahashi SI, Fujii A, Inubushi Y, Komiya N. Synthesis of 2-substituted quinones, vitamin K3, and vitamin K1 from p-cresol. BF3·OEt2-catalyzed methyl migration of 4-tert-butyldioxycyclohexadienones. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2010.02.134] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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30
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Rishavy MA, Berkner KL. Insight into the coupling mechanism of the vitamin K-dependent carboxylase: mutation of histidine 160 disrupts glutamic acid carbanion formation and efficient coupling of vitamin K epoxidation to glutamic acid carboxylation. Biochemistry 2008; 47:9836-46. [PMID: 18717596 DOI: 10.1021/bi800296r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Vitamin K-dependent (VKD) proteins become activated by the VKD carboxylase, which converts Glu's to carboxylated Glu's (Gla's) in their Gla domains. The carboxylase uses vitamin K epoxidation to drive Glu carboxylation, and the two half-reactions are coupled in 1:1 stoichiometry by an unknown mechanism. We now report the first identification of a residue, His160, required for coupling. A H160A mutant showed wild-type levels of epoxidation but substantially less carboxylation. Monitoring proton abstraction using a peptide with Glu tritiated at the gamma-carbon position revealed that poor coupling was due to impaired carbanion formation. H160A showed a 10-fold lower ratio of tritium release to vitamin K epoxidation than wild-type enzyme (i.e., 0.12 versus 1.14, respectively), which could fully account for the fold decrease in coupling efficiency. The Ala substitution in His160 did not affect the K m for vitamin K and caused only a 2-fold increase in the K m for Glu and 2-fold decrease in the activation of vitamin K epoxidation by Glu. The H160A K m for CO 2 was 5-fold higher than the wild-type enzyme. However, the k cat for H160A carboxylation was 8-9-fold lower than the wild-type enzyme with all three substrates (i.e., Glu, CO 2, and vitamin K), suggesting a catalytic role for His160 in carbanion formation. We propose that His160 facilitates the formation of the transition state for carbanion formation. His160 is highly conserved in metazoan VKD carboxylases but not in some bacterial orthologues (acquired by horizontal gene transfer), which has implications for how bacteria have adapted the carboxylase for novel functions.
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Affiliation(s)
- Mark A Rishavy
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
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31
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Abstract
Vitamin K-dependent (VKD) protein carboxylation uses vitamin K epoxidation to convert Glus to carboxylated Glus (Glas), rendering VKD proteins active in physiologies that include hemostasis, apoptosis, bone mineralization, calcium homeostasis, growth control, and signal transduction. Clusters of Glus are modified by a processive carboxylase, generating a calcium-binding module that allows binding to either hydroxyapatite in the extracellular matrices or cell surfaces where anionic phospholipids become exposed, for example, during apoptosis or cell activation. Naturally occurring carboxylase mutations have been informative for function and are associated with bleeding complications and, surprisingly, a pseudoxanthoma elasticum (PXE)-like phenotype. A major advance in defining carboxylase function is the identification of the base that initiates carboxylation, which raises interesting possibilities for how vitamin K epoxidation is regulated by Glu substrate and carboxylase membrane topology. Vitamin K oxidoreductase (VKOR), the target of warfarin, generates the reduced vitamin K cofactor used by the carboxylase. Oxidation of active site thiols during vitamin K reduction inactivates VKOR, and activity is regenerated by an unknown reductase. The amounts of reduced vitamin K limit the capacity for carboxylation in cells, and overexpression of VKOR, but not carboxylase, improves carboxylation. However, the effect of VKOR overexpression is small, possibly because the reductase that regenerates VKOR activity is saturated. The review discusses these advances, as well as the potential impact of secretory components on carboxylation, which occurs during VKD protein secretion. Also discussed is the role of the carboxylase in mammals and lower organisms, including the bacterial pathogen Leptospira interrogans that has acquired a VKD carboxylase by horizontal transfer.
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Affiliation(s)
- Kathleen L Berkner
- Department of Molecular Cardiology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Lerner Research Institute, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
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32
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Abstract
Vitamin K epoxide reductase (VKOR) is an integral membrane protein that catalyzes the reduction of vitamin K 2,3-epoxide and vitamin K to vitamin K hydroquinone, a cofactor required for the gamma-glutamyl carboxylation reaction. VKOR is highly sensitive to inhibition by warfarin, the most commonly prescribed oral anticoagulant. Warfarin inhibition of VKOR decreases the concentration of reduced vitamin K, which reduces the rate of vitamin K-dependent carboxylation and leads to under-carboxylated, inactive vitamin K-dependent proteins. It is proposed that an active site disulfide needs to be reduced for the enzyme to be active. VKOR uses two sulfhydryl groups for the catalytic reaction and these two sulfhydryl groups are oxidized back to a disulfide bond during each catalytic cycle. The recent identification of the gene encoding VKOR allows us to study its structure and function relationship at the molecular level. The membrane topology model shows that VKOR spans the endoplasmic reticulum membrane three times with its amino-terminus residing in the lumen and the carboxyl-terminus residing in the cytoplasm. Both the active site (cysteines 132 and 135) and the proposed warfarin binding site (tyrosine 139) reside in the third transmembrane helix. VKOR is made at high levels in insect cells and is relatively easily purified. This should allow the determination of its three-dimensional structure. A detailed mechanism has been published and the purified enzyme should allow the testing of this mechanism. A major unanswered question is the physiological reductant of VKOR.
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Affiliation(s)
- Jian-Ke Tie
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3280, USA
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33
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Abstract
The vitamin K-dependent carboxylase carries out the posttranslational modification of specific glutamate residues in proteins to gamma-carboxy glutamic acid (Gla) in the presence of reduced vitamin K, molecular oxygen, and carbon dioxide. In the process, reduced vitamin K is converted to vitamin K epoxide, which is subsequently reduced to vitamin K, by vitamin K epoxide reductase (VKOR) for use in the carboxylation reaction. The modification has a wide range of physiological implications, including hemostasis, bone calcification, and signal transduction. The enzyme interacts with a high affinity gamma-carboxylation recognition sequence (gamma-CRS) of the substrate and carries out multiple modifications of the substrate before the product is released. This mechanism ensures complete carboxylation of the Gla domain of the coagulation factors, which is essential for their biological activity. gamma-Carboxylation, originally discovered in mammals, is widely distributed in the animal kingdom. It has been characterized in sea squirt (Ciona intestinalis), in flies (Drosophila melanogaster), and in marine snails (Conus textile), none of which have a blood coagulation system similar to mammals. The cone snails express a large array of gamma-carboxylated peptides that modulate the activity of ion channels. These findings have led to the suggestion that gamma-carboxylation is an extracellular posttranslational modification that antedates the divergence of molluscs, arthropods, and chordates. I will first summarize recent understanding of gamma-carboxylase and gamma-carboxylation gleaned from experiments using the mammalian enzyme, and then I will briefly describe the available information on gamma-carboxylation in D. melanogaster and C. textile.
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Affiliation(s)
- Pradip K Bandyopadhyay
- Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, Utah 84112, USA
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34
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Abstract
In the reaction cycle of glutamate carboxylase, vitamin K epoxidation by O2 has been proposed to generate a very strong base able to remove a proton from the gamma carbon of a Glu residue, thus yielding a Glu-based carbanion that readily reacts with CO2. We have used hybrid density functional theory to study this appealing mechanism. Our calculations show a very exergonic four-step mechanism with the reaction of (triplet) O2 with the singlet vitamin K anion as the rate-limiting step, with a rate similar to the experimental value. Our study also establishes the need to apply continuum models when performing the optimization of minimum-energy crossing points between potential energy surfaces of different multiplicities for enzyme model systems.
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Affiliation(s)
- Pedro J Silva
- REQUIMTE, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, Rua Carlos da Maia, 296, 4200-150 Porto-Portugal
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35
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Davis CH, Deerfield D, Wymore T, Stafford DW, Pedersen LG. A quantum chemical study of the mechanism of action of Vitamin K epoxide reductase (VKOR). J Mol Graph Model 2007; 26:401-8. [PMID: 17182266 DOI: 10.1016/j.jmgm.2006.10.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Accepted: 10/24/2006] [Indexed: 11/25/2022]
Abstract
A reaction path including transition states is generated for the Silverman mechanism [R.B. Silverman, Chemical model studies for the mechanism of Vitamin K epoxide reductase, J. Am. Chem. Soc. 103 (1981) 5939-5941] of action for Vitamin K epoxide reductase (VKOR) using quantum mechanical methods (B3LYP/6-311G**). VKOR, an essential enzyme in mammalian systems, acts to convert Vitamin K epoxide, formed by Vitamin K carboxylase, to its (initial) quinone form for cellular reuse. This study elaborates on a prior work that focused on the thermodynamics of VKOR [D.W. Deerfield II, C.H. Davis, T. Wymore, D.W. Stafford, L.G. Pedersen, Int. J. Quant. Chem. 106 (2006) 2944-2952]. The geometries of proposed model intermediates and transition states in the mechanism are energy optimized. We find that once a key disulfide bond is broken, the reaction proceeds largely downhill. An important step in the conversion of the epoxide back to the quinone form involves initial protonation of the epoxide oxygen. We find that the source of this proton is likely a free mercapto group rather than a water molecule. The results are consistent with the current view that the widely used drug Warfarin likely acts by blocking binding of Vitamin K at the VKOR active site and thereby effectively blocking the initiating step. These results will be useful for designing more complete QM/MM studies of the enzymatic pathway once three-dimensional structural data is determined and available for VKOR.
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Affiliation(s)
- Charles H Davis
- Department of Biochemistry and Biophysics, UNC-CH, Chapel Hill, NC 27599, United States
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Davis CH, Deerfield D, Wymore T, Stafford DW, Pedersen LG. A quantum chemical study of the mechanism of action of Vitamin K carboxylase (VKC). J Mol Graph Model 2007; 26:409-14. [PMID: 17182265 DOI: 10.1016/j.jmgm.2006.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Accepted: 10/24/2006] [Indexed: 10/23/2022]
Abstract
A reaction path including transition states is generated for the Dowd mechanism [P. Dowd, R. Hershlne, S.W. Ham, S. Naganathan. Vitamin K and energy transduction: a base strength amplification mechanism. Science 269 (2005) 1684-1691] of action for Vitamin K carboxylase (VKC) using quantum chemical methods (B3LYP/6-311G**). VKC, an essential enzyme in mammalian systems, catalyzes the conversion of hydroquinone form of Vitamin K to the epoxide form in the presence of oxygen. An intermediate species of the oxidation of Vitamin K, an alkoxide, acts apparently to abstract the gamma hydrogen from specifically located glutamate residues. We are able to follow the Dowd proposed path to generate this alkoxide species. The geometries of the proposed model intermediates and transition states in the mechanism are energy optimized. We find that the most energetic step in the mechanism is the uni-deprotonation of the hydroquinone - once this occurs, there is only a small barrier of 3.5kcal/mol for the interaction of oxygen with the carbon to be attacked - and then the reaction proceeds downhill in free energy to form the critical alkoxide species. The results are consistent with the idea that the enzyme probably acts to facilitate the formation of the epoxide by reducing the energy required to deprotonate the hydroquinone form.
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Affiliation(s)
- Charles H Davis
- Department of Biochemistry and Biophysics, UNC-CH, Chapel Hill, 27599, United States
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37
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Davis CH, Ii DD, Stafford DW, Pedersen LG. Quantum chemical study of the mechanism of action of vitamin K carboxylase (VKC). IV. Intermediates and transition states. J Phys Chem A 2007; 111:7257-61. [PMID: 17503787 DOI: 10.1021/jp068564y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We studied proposed steps for the enzymatic formation of gamma-carboxyglutamic acid by density functional theory (DFT) quantum chemistry. Our results for one potentially feasible mechanism show that a vitamin K alkoxide intermediate can abstract a proton from glutamic acid at the gamma-carbon to form a carbanion and vitamin K epoxide. The hydrated carbanion can then react with CO2 to form gamma-carboxyglutamic acid. Computations at the B3LYP/6-311G** level were used to determine the intermediates and transition states for the overall process. The activation free energy for the gas-phase path is 22 kcal/mol, with the rate-limiting step for the reaction being the attack of the carbanion on CO2. Additional solvation studies, however, indicate that the formation of the carbanion step can be competitive with the CO2 attack step in high-dielectric systems. We relate these computations to the entire vitamin K cycle in the blood coagulation cascade, which is essential for viability of vertebrates.
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Affiliation(s)
- Charles H Davis
- Department of Biochemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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38
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Tie JK, Zheng MY, Pope RM, Straight DL, Stafford DW. Identification of the N-linked glycosylation sites of vitamin K-dependent carboxylase and effect of glycosylation on carboxylase function. Biochemistry 2007; 45:14755-63. [PMID: 17144668 PMCID: PMC3956053 DOI: 10.1021/bi0618518] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The vitamin K-dependent carboxylase is an integral membrane protein which is required for the post-translational modification of a variety of vitamin K-dependent proteins. Previous studies have suggested carboxylase is a glycoprotein with N-linked glycosylation sites. In this study, we identify the N-glycosylation sites of carboxylase by mass spectrometric peptide mapping analyses combined with site-directed mutagenesis. Our mass spectrometric results show that the N-linked glycosylation in carboxylase occurs at positions N459, N550, N605, and N627. Eliminating these glycosylation sites by changing asparagine to glutamine caused the mutant carboxylase to migrate faster on SDS-PAGE gels, adding further evidence that these sites are glycosylated. In addition, the mutation studies identified N525, a site that cannot be recovered by mass spectroscopy analysis, as a glycosylation site. Furthermore, the potential glycosylation site at N570 is glycosylated only if all five natural glycosylation sites are simultaneously mutated. Removal of the oligosaccharides by glycosidase from wild-type carboxylase or by elimination of the functional glycosylation sites by site-directed mutagenesis did not affect either the carboxylation or epoxidation activity when the small FLEEL pentapeptide was used as a substrate, suggesting that N-linked glycosylation is not required for the enzymatic function of carboxylase. In contrast, when site N570 and the five natural glycosylation sites were mutated simultaneously, the resulting carboxylase protein was degraded. Our results suggest that N-linked glycosylation is not essential for carboxylase enzymatic activity but is important for protein folding and stability.
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Affiliation(s)
| | | | | | | | - Darrel W. Stafford
- Author to whom all correspondence should be addressed: Darrel W. Stafford Department of Biology University of North Carolina at Chapel Hill Chapel Hill, NC 27599-3280 Phone: 919-962-0597 Fax: 919-962-9266
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39
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Chu PH, Huang TY, Williams J, Stafford DW. Purified vitamin K epoxide reductase alone is sufficient for conversion of vitamin K epoxide to vitamin K and vitamin K to vitamin KH2. Proc Natl Acad Sci U S A 2006; 103:19308-13. [PMID: 17164330 PMCID: PMC1698442 DOI: 10.1073/pnas.0609401103] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
More than 21 million prescriptions for warfarin are written yearly in the U.S. Despite its importance, warfarin's target, vitamin K epoxide reductase (VKOR), has resisted purification since its identification in 1972. Here, we report its purification and reconstitution. HPC4, a calcium-specific antibody that recognizes a 12-aa tag, was used to purify and identify VKOR. Partial reconstitution is achieved on the column by washing with 0.4% dioleoylphosphatidylcholine/0.4% deoxycholate. Activity is completely recovered by dialysis against a buffer containing a reducing agent but lacking dioleoylphosphatidylcholine/deoxycholate. Removal of detergent from the eluted proteins apparently facilitates liposome formation. Purified recombinant VKOR with tag is approximately 21 kDa, as expected; fully active; and > 93% pure. The concentration of warfarin for 50% inhibition is the same for purified protein and microsomes. It has been reported that VKOR is a multisubunit enzyme. Our results, however, suggest that a single peptide can accomplish both the conversion of vitamin K epoxide to vitamin K and vitamin K to reduced vitamin K. This purification will allow further characterization of VKOR in relation to other components of the vitamin K cycle and should facilitate its structural determination.
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Affiliation(s)
- Pei-Hsuan Chu
- *Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280
| | - Teng-Yi Huang
- Department of Chemistry, Purdue University, West Lafayette, IN 47907; and
| | - Jason Williams
- Laboratory of Structural Biology, National Institute on Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709
| | - D. W. Stafford
- *Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280
- To whom correspondence should be addressed. E-mail:
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40
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Abstract
A flock of Rambouillet sheep was examined because of increased lamb mortality due to ineffective hemostasis at parturition. Decreased activities of coagulation factors II, VII, IX, and X, and severely reduced hepatic gamma-glutamyl carboxylase activity with adequate vitamin K 2,3 epoxide reductase activity was determined.(1,)(21) Parenteral vitamin K(1) supplementation did not improve vitamin K-dependent coagulation factor activities in 3 affected lambs. Affected lamb gamma-glutamyl carboxylase deoxyribonucleic acid was sequenced, and 4 single nucleotide polymorphisms (SNPs 2-5) of the gamma-glutamyl carboxylase gene were identified. Single nucleotide polymorphism-4 results in an arginine to stop codon (UGA) substitution, which prematurely terminates the peptide at residue 686 (R686Stop). This genotype (GATT/GATT) has a strong association with the coagulopathy observed in clinically affected lambs, P < 0.001. The frequency of SNP-3 in exon 11 (R486H) within the MARC 1.1 database is high in the US sheep population overall. Gamma-glutamyl carboxylase activity in hepatic microsomes from a SNP-3 homozygous lamb lacking the SNP-4 mutation (GACC/GACC) was similar to control sheep homozygous for arginine at 486 and also lacking SNP-4 (TGCC/TGCC), indicating that the R486H does not measurably impact gamma-glutamyl carboxylase activity. The remaining two SNPs (2 and 5) are located within non-coding intron sequences. These 4 SNPs allowed for determining the genotype associated with the observed fatal coagulopathy. Screening for the premature truncation (SNP-4) based on the presence of a Bbv I restriction site in clinically normal lambs but not in the homozygous affected lambs allows for detection of the heterozygous state (GATT/GACC), because carrier animals are clinically normal.
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Affiliation(s)
- J S Johnson
- Colorado State University, College of Veterinary Medicine and Biomedical Sciences, Department of Microbiology, Immunology, and Pathology, Fort Collins, CO, USA
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Bandyopadhyay PK, Clark K, Stevenson BJ, Rivier JE, Olivera BM, Golic KG, Rong YS. Biochemical characterization of Drosophila gamma-glutamyl carboxylase and its role in fly development. Insect Mol Biol 2006; 15:147-56. [PMID: 16640725 DOI: 10.1111/j.1365-2583.2006.00619.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
To investigate structure-function relationships in gamma-glutamyl carboxylases, the enzyme from Drosophila melanogaster was characterized. Four cysteine residues were shown to be important determinants for enzymatic activity. Native Drosophila substrates have not yet been identified, but propeptides of human prothrombin and factor IX are recognized by the Drosophila enzyme. The presence of the propeptide region increased apparent affinity by approximately 200-fold, and mutation of a hydrophobic residue of factor IX propeptide (F-16A) decreased carboxylation by 90%, as in the human enzyme. Substrate recognition appears to be highly conserved between the human and Drosophila gamma-glutamyl carboxylases. Inactivation of Drosophila gamma-glutamyl carboxylase by non-sense mutations or insertional mutagenesis by P-element insertion have no apparent effects on growth and fertility under laboratory conditions.
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Affiliation(s)
- P K Bandyopadhyay
- Department of Biology, University of Utah, Salt Lake City, 84112, USA.
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42
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Abstract
Previously we reported that we could increase the fraction of carboxylated factor X by reducing the affinity of the propeptide for its binding site on human gamma glutamyl carboxylase. We attributed this to an increased turnover rate. However, even with the reduced affinity propeptide, when sufficient overproduction of factor X is achieved, there is still a significant fraction of uncarboxylated recombinant factor X. We report here that the factor X of such a cell line was only 52% carboxylated but that the fraction of carboxylated factor X could be increased to 92% by coexpressing the recently identified gene for vitamin K epoxide reductase. Because vitamin K is in excess in both the untransfected and vitamin K epoxide reductase (VKOR)–transfected cells, the simplest explanation for this result is that VKOR catalyzes both the reduction of vitamin K epoxide to vitamin K and the conversion of vitamin K to vitamin K hydroquinone. In addition to its mechanistic relevance, this observation has practical implications for overproducing recombinant vitamin K–dependent proteins for therapeutic use.
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Affiliation(s)
- Yan-Mei Sun
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280, USA
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43
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Abstract
The vitamin K-dependent (VKD) carboxylase uses the oxygenation of vitamin K to convert glutamyl residues (Glus) to carboxylated Glus (Glas) in VKD proteins, rendering them active in a broad range of physiologies that include hemostasis, apoptosis, bone development, arterial calcification, signal transduction, and growth control. The carboxylase has a high-affinity site that selectively binds VKD proteins, usually through their propeptide, and also has a second low-affinity site of VKD protein interaction. Propeptide binding increases carboxylase affinity for the Glu substrate, and the coordinated binding of the VKD propeptide and Glu substrate increases carboxylase affinity for vitamin K and activity, possibly through a mechanism of substrate-assisted catalysis. Tethering of VKD proteins to the carboxylase allows clusters of Glus to be modified to Glas by a processive mechanism that becomes disrupted during warfarin therapy. Warfarin inhibits a vitamin K oxidoreductase that generates the reduced vitamin K cofactor required for continuous carboxylation and causes decreased carboxylase catalysis and increased dissociation of partially carboxylated, inactive VKD proteins. The availability of reduced vitamin K may also control carboxylation in r-VKD protein-expressing cells, where the amounts of reduced vitamin K are sufficient for full carboxylation of low, but not high, expression levels of VKD proteins, and where carboxylation is not improved by overexpression of r-carboxylase. This review discusses these recent advances in understanding the mechanism of carboxylation. Also covered is the identification of functional carboxylase residues, a brief description of the role of VKD proteins in mammalian and lower organisms, and the potential impact of quality control components on carboxylation, which occurs in the endoplasmic reticulum during the secretion of VKD proteins.
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Affiliation(s)
- Kathleen L Berkner
- Department of Molecular Cardiology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Lerner Research Institute, Cleveland, Ohio 44195, USA.
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Rishavy MA, Hallgren KW, Yakubenko AV, Zuerner RL, Runge KW, Berkner KL. The vitamin K-dependent carboxylase has been acquired by Leptospira pathogens and shows altered activity that suggests a role other than protein carboxylation. J Biol Chem 2005; 280:34870-7. [PMID: 16061481 DOI: 10.1074/jbc.m504345200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leptospirosis is an emerging infectious disease whose pathology includes a hemorrhagic response, and sequencing of the Leptospira interrogans genome revealed an ortholog of the vitamin K-dependent (VKD) carboxylase as one of several hemostatic proteins present in the bacterium. Until now, the VKD carboxylase was known to be present only in the animal kingdom (i.e. metazoans that include mammals, fish, snails, and insects), and this restricted distribution and high sequence similarity between metazoan and Leptospira orthologs strongly suggests that Leptospira acquired the VKD carboxylase by horizontal gene transfer. In metazoans, the VKD carboxylase is bifunctional, acting as an epoxidase that oxygenates vitamin K to a strong base and a carboxylase that uses the base to carboxylate Glu residues in VKD proteins, rendering them active in hemostasis and other physiologies. In contrast, the Leptospira ortholog showed epoxidase but not detectable carboxylase activity and divergence in a region of identity in all known metazoan VKD carboxylases that is important to Glu interaction. Furthermore, although the mammalian carboxylase is regulated so that vitamin K epoxidation does not occur unless Glu substrate is present, the Leptospira VKD epoxidase showed unfettered epoxidation in the absence of Glu substrate. Finally, human VKD protein orthologs were not detected in the L. interrogans genome. The combined data, then, suggest that Leptospira exapted the metazoan VKD carboxylase for some use other than VKD protein carboxylation, such as using the strong vitamin K base to drive a new reaction or to promote oxidative damage or depleting vitamin K to indirectly inhibit host VKD protein carboxylation.
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Affiliation(s)
- Mark A Rishavy
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, Ohio 44195, USA
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Abstract
Post-translational modification of glutamate to gamma carboxyl glutamate is required for the activity of vitamin K-dependent proteins. Carboxylation is accomplished by the enzyme gamma glutamyl carboxylase (GGCX) which requires the propeptide-containing substrate and three co-substrates: reduced vitamin K, CO2, and O2. Most propeptides bind tightly to GGCX and all of the Glu residues that will be modified are modified during one binding event. Complete carboxylation is thus dependent upon the rate of carboxylation and the dissociation rate constant of the substrate from the GGCX enzyme. If the propeptide is released before carboxylation is complete, partially carboxylated vitamin K-dependent proteins are produced. The rate of carboxylation is mainly controlled by the level of reduced vitamin K available for the reactions while the dissociation rate constant is dependent upon both the propeptide and the Gla domain of the substrate. In addition, there are allosteric effects that increase the rate of dissociation of the fully carboxylated substrates. Carboxylation requires the abstraction of a proton from the 4-carbon of glutamate by reduced vitamin K and results in the conversion of vitamin K to vitamin K epoxide. The vitamin K epoxide must be recycled to vitamin K before it can be reused, a reaction catalyzed by the enzyme vitamin K epoxide reductase (VKOR). The gene for VKOR has recently been identified but the enzyme itself has not been purified to homogeneity. It appears, however, that most of the variability observed in patients response to warfarin may be attributed to variability in the VKOR gene.
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Affiliation(s)
- D W Stafford
- Department of Biology and Pathology, University of North Carolina, Chapel Hill, NC 27599-3280, USA.
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46
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Abstract
The brain is enriched with sphingolipids, which are important membrane constituents and major lipid signaling molecules that have a role in motor and cognitive behavior. Vitamin K has been implicated in brain sphingolipid metabolism for more than 30 years. The in vitro and in vivo studies to date suggest a role of vitamin K in the regulation of multiple enzymes involved in sphingolipid metabolism within the myelin-rich regions in the brain. However, the precise mechanisms of action are not well understood. Further, the physiological consequences of the observed effects of vitamin K on sphingolipid metabolism have not been systematically studied.
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Affiliation(s)
- Natalia A Denisova
- Nutrition and Neurocognition Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts 02111, USA.
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47
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Wajih N, Sane DC, Hutson SM, Wallin R. Engineering of a Recombinant Vitamin K-dependent γ-Carboxylation System with Enhanced γ-Carboxyglutamic Acid Forming Capacity. J Biol Chem 2005; 280:10540-7. [PMID: 15640149 DOI: 10.1074/jbc.m413982200] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The vitamin K-dependent gamma-carboxylation system in the endoplasmic reticulum membrane responsible for gamma-carboxyglutamic acid modification of vitamin K-dependent proteins includes gamma-carboxylase and vitamin K 2,3-epoxide reductase (VKOR). An understanding of the mechanism by which this system works at the molecular level has been hampered by the difficulty of identifying VKOR involved in warfarin sensitive reduction of vitamin K 2,3-epoxide to reduced vitamin K(1)H(2), the gamma-carboxylase cofactor. Identification and cloning of VKORC1, a proposed subunit of a larger VKOR enzyme complex, have provided opportunities for new experimental approaches aimed at understanding the vitamin K-dependent gamma-carboxylation system. In this work we have engineered stably transfected baby hamster kidney cells containing gamma-carboxylase and VKORC1 cDNA constructs, respectively, and stably double transfected cells with the gamma-carboxylase and the VKORC1 cDNA constructs in a bicistronic vector. All engineered cells showed increased activities of the enzymes encoded by the cDNAs. However increased activity of the gamma-carboxylation system, where VKOR provides the reduced vitamin K(1)H(2) cofactor, was measured only in cells transfected with VKORC1 and the double transfected cells. The results show that VKOR is the rate-limiting step in the gamma-carboxylation system and demonstrate successful engineering of cells containing a recombinant vitamin K-dependent gamma-carboxylation system with enhanced capacity for gamma-carboxyglutamic acid modification. The proposed thioredoxin-like (132)CXXC(135) redox center in VKORC1 was tested by expressing the VKORC1 mutants Cys(132)/Ser and Cys(135)/Ser in BHK cells. Both of the expressed mutant proteins were inactive supporting the existence of a CXXC redox center in VKOR.
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MESH Headings
- Animals
- Binding Sites
- Blotting, Western
- Carboxylic Acids/metabolism
- Cell Line
- Cell Line, Tumor
- Cloning, Molecular
- Cricetinae
- Cysteine/chemistry
- DNA/metabolism
- DNA, Complementary/metabolism
- Electrophoresis, Gel, Two-Dimensional
- Electrophoresis, Polyacrylamide Gel
- Factor X/chemistry
- Genetic Vectors
- Liver/metabolism
- Male
- Microsomes/metabolism
- Microsomes, Liver/metabolism
- Mixed Function Oxygenases/metabolism
- Mutagenesis, Site-Directed
- Mutation
- Oxidation-Reduction
- Peptides/chemistry
- Plasmids/metabolism
- Protein Engineering
- Protein Structure, Tertiary
- Rats
- Rats, Sprague-Dawley
- Recombinant Proteins/chemistry
- Serine/chemistry
- Thioredoxins/chemistry
- Transfection
- Vitamin K/chemistry
- Vitamin K Epoxide Reductases
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Affiliation(s)
- Nadeem Wajih
- Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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48
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Abstract
Recent advances in the discovery of new functions for vitamin K-dependent (VKD) proteins and in defining vitamin K nutriture have led to a substantial revision in our understanding of vitamin K physiology. The only unequivocal function for vitamin K is as a cofactor for the carboxylation of VKD proteins which renders them active. While vitamin K was originally associated only with hepatic VKD proteins that participate in hemostasis, VKD proteins are now known to be present in virtually every tissue and to be important to bone mineralization, arterial calcification, apoptosis, phagocytosis, growth control, chemotaxis, and signal transduction. The development of improved methods for analyzing vitamin K has shed considerable insight into the relative importance of different vitamin K forms in the diet and their contribution to hepatic vs. non-hepatic tissue. New assays that measure the extent of carboxylation in VKD proteins have revealed that while the current recommended daily allowance for vitamin K is sufficient for maintaining functional hemostasis, the undercarboxylation of at least one non-hemostatic protein is frequently observed in the general population. The advances in defining VKD protein function and vitamin K nutriture are described, as is the potential impact of VKD proteins on atherosclerosis. Many of the VKD proteins contribute to atherogenesis. Recent studies suggest involvement in arterial calcification, which may be influenced by dietary levels of vitamin K and by anticoagulant drugs such as warfarin that antagonize vitamin K action.
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Affiliation(s)
- K L Berkner
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA.
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49
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Tie JK, Jin DY, Loiselle DR, Pope RM, Straight DL, Stafford DW. Chemical Modification of Cysteine Residues Is a Misleading Indicator of Their Status as Active Site Residues in the Vitamin K-dependent γ-Glutamyl Carboxylation Reaction. J Biol Chem 2004; 279:54079-87. [PMID: 15492002 DOI: 10.1074/jbc.m408945200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enzymatic activity of the vitamin K-dependent proteins requires the post-translational conversion of specific glutamic acids to gamma-carboxy-glutamic acid by the integral membrane enzyme, gamma-glutamyl carboxylase. Whether or not cysteine residues are important for carboxylase activity has been the subject of a number of studies. In the present study we used carboxylase with point mutations at cysteines, chemical modification, and mass spectrometry to examine this question. Mutation of any of the free cysteine residues to alanine or serine had little effect on carboxylase activity, although C343A mutant carboxylase had only 38% activity compared with that of wild type. In contrast, treatment with either thiol-reactive reagent 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid, disodium salt, or sodium tetrathionate, caused complete loss of activity. We identified the residues modified, using matrix-assisted laser desorption/ionization time of flight mass spectrometry, as Cys(323) and Cys(343). According to our results, these residues are on the cytoplasmic side of the microsomal membrane, whereas catalytic residues are expected to be on the lumenal side of the membrane. Carboxylase was partially protected from chemical modification by factor IXs propeptide. Although all mutant carboxylases bound propeptide with normal affinity, chemical modification caused a >100-fold decrease in carboxylase affinity for the consensus propeptide. We conclude that cysteine residues are not directly involved in carboxylase catalysis, but chemical modification of Cys(323) and Cys(343) may disrupt the three-dimensional structure, resulting in inactivation.
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Affiliation(s)
- Jian-Ke Tie
- Departments of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Rishavy MA, Pudota BN, Hallgren KW, Qian W, Yakubenko AV, Song JH, Runge KW, Berkner KL. A new model for vitamin K-dependent carboxylation: the catalytic base that deprotonates vitamin K hydroquinone is not Cys but an activated amine. Proc Natl Acad Sci U S A 2004; 101:13732-7. [PMID: 15365175 PMCID: PMC518825 DOI: 10.1073/pnas.0404989101] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vitamin K-dependent (VKD) proteins require carboxylation for diverse functions that include hemostasis, apoptosis, and Ca(2+) homeostasis, yet the mechanism of carboxylation is not well understood. Combined biochemical and chemical studies have led to a long-standing model in which a carboxylase Cys catalytic base deprotonates vitamin K hydroquinone (KH(2)), leading to KH(2) oxygenation and Glu carboxylation. We previously identified human carboxylase Cys-99 and Cys-450 as catalytic base candidates: Both were modified by N-ethylmaleimide (NEM) and Ser-substituted mutants retained partial activity, suggesting that the catalytic base is activated for increased basicity. Mutants with Cys-99 or Cys-450 substituted by Ala, which cannot ionize to function as a catalytic base, were therefore analyzed. Both single and double mutants had activity, indicating that Cys-99 and Cys-450 do not deprotonate KH(2). [(14)C]NEM modification of C99A/C450A revealed one additional reactive group; however, Ser-substituted mutants of each of the eight remaining Cys retained substantial activity. To unequivocally test, then, whether any Cys or Cys combination acts as the catalytic base, a mutant with all 10 Cys substituted by Ala was generated. This mutant showed 7% wild-type activity that depended on factor IX coexpression, indicating a VKD protein effect on carboxylase maturation. NEM and diethyl pyrocarbonate inhibition suggested that the catalytic base is an activated His. These results change the paradigm for VKD protein carboxylation. The identity of the catalytic base is critical to understanding carboxylase mechanism and this work will therefore impact both reinterpretation of previous studies and future ones that define how this important enzyme functions.
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Affiliation(s)
- Mark A Rishavy
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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