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Purohit V, Steussy CN, Rosales AR, Critchelow CJ, Schmidt T, Helquist P, Wiest O, Mesecar A, Cohen AE, Stauffacher CV. pH-dependent reaction triggering in PmHMGR crystals for time-resolved crystallography. Biophys J 2024; 123:622-637. [PMID: 38327055 PMCID: PMC10938121 DOI: 10.1016/j.bpj.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/22/2023] [Accepted: 02/02/2024] [Indexed: 02/09/2024] Open
Abstract
Serial crystallography and time-resolved data collection can readily be employed to investigate the catalytic mechanism of Pseudomonas mevalonii 3-hydroxy-3-methylglutaryl (HMG)-coenzyme-A (CoA) reductase (PmHMGR) by changing the environmental conditions in the crystal and so manipulating the reaction rate. This enzyme uses a complex mechanism to convert mevalonate to HMG-CoA using the co-substrate CoA and cofactor NAD+. The multi-step reaction mechanism involves an exchange of bound NAD+ and large conformational changes by a 50-residue subdomain. The enzymatic reaction can be run in both forward and reverse directions in solution and is catalytically active in the crystal for multiple reaction steps. Initially, the enzyme was found to be inactive in the crystal starting with bound mevalonate, CoA, and NAD+. To observe the reaction from this direction, we examined the effects of crystallization buffer constituents and pH on enzyme turnover, discovering a strong inhibition in the crystallization buffer and a controllable increase in enzyme turnover as a function of pH. The inhibition is dependent on ionic concentration of the crystallization precipitant ammonium sulfate but independent of its ionic composition. Crystallographic studies show that the observed inhibition only affects the oxidation of mevalonate but not the subsequent reactions of the intermediate mevaldehyde. Calculations of the pKa values for the enzyme active site residues suggest that the effect of pH on turnover is due to the changing protonation state of His381. We have now exploited the changes in ionic inhibition in combination with the pH-dependent increase in turnover as a novel approach for triggering the PmHMGR reaction in crystals and capturing information about its intermediate states along the reaction pathway.
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Affiliation(s)
- Vatsal Purohit
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana
| | - Calvin N Steussy
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana
| | - Anthony R Rosales
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana
| | | | - Tim Schmidt
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana
| | - Paul Helquist
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana
| | - Olaf Wiest
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana
| | - Andrew Mesecar
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana; Purdue Institute for Cancer Research, Purdue University, West Lafayette, Indiana; Department of Biochemistry, Purdue University, West Lafayette, Indiana
| | - Aina E Cohen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California
| | - Cynthia V Stauffacher
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana; Purdue Institute of Inflammation, Immunology and Infectious Diseases, Purdue University, West Lafayette, Indiana; Purdue Institute for Cancer Research, Purdue University, West Lafayette, Indiana.
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2
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Patel HN, Haines BE, Stauffacher CV, Helquist P, Wiest O. Computational Study of Base-Catalyzed Thiohemiacetal Decomposition in Pseudomonas mevalonii HMG-CoA Reductase. J Phys Chem B 2023. [PMID: 37219997 DOI: 10.1021/acs.jpcb.2c08969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Thiohemiacetals are key intermediates in the active sites of many enzymes catalyzing a variety of reactions. In the case of Pseudomonas mevalonii 3-hydroxy-3-methylglutaryl coenzyme A reductase (PmHMGR), this intermediate connects the two hydride transfer steps where a thiohemiacetal is the product of the first hydride transfer and its breakdown forms the substrate of the second one, serving as the intermediate during cofactor exchange. Despite the many examples of thiohemiacetals in a variety of enzymatic reactions, there are few studies that detail their reactivity. Here, we present computational studies on the decomposition of the thiohemiacetal intermediate in PmHMGR using both QM-cluster and QM/MM models. This reaction mechanism involves a proton transfer from the substrate hydroxyl to an anionic Glu83 followed by a C-S bond elongation stabilized by a cationic His381. The reaction provides insight into the varying roles of the residues in the active site that favor this multistep mechanism.
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Affiliation(s)
- Himani N Patel
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Brandon E Haines
- Department of Chemistry, Westmont College, Santa Barbara, California 93108, United States
| | - Cynthia V Stauffacher
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Paul Helquist
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Olaf Wiest
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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3
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Bose S, Steussy CN, López-Pérez D, Schmidt T, Kulathunga SC, Seleem MN, Lipton M, Mesecar AD, Rodwell VW, Stauffacher CV. Targeting Enterococcus faecalis HMG-CoA reductase with a non-statin inhibitor. Commun Biol 2023; 6:360. [PMID: 37012403 PMCID: PMC10070635 DOI: 10.1038/s42003-023-04639-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 02/28/2023] [Indexed: 04/05/2023] Open
Abstract
HMG-CoA reductase (HMGR), a rate-limiting enzyme of the mevalonate pathway in Gram-positive pathogenic bacteria, is an attractive target for development of novel antibiotics. In this study, we report the crystal structures of HMGR from Enterococcus faecalis (efHMGR) in the apo and liganded forms, highlighting several unique features of this enzyme. Statins, which inhibit the human enzyme with nanomolar affinity, perform poorly against the bacterial HMGR homologs. We also report a potent competitive inhibitor (Chembridge2 ID 7828315 or compound 315) of the efHMGR enzyme identified by a high-throughput, in-vitro screening. The X-ray crystal structure of efHMGR in complex with 315 was determined to 1.27 Å resolution revealing that the inhibitor occupies the mevalonate-binding site and interacts with several key active site residues conserved among bacterial homologs. Importantly, 315 does not inhibit the human HMGR. Our identification of a selective, non-statin inhibitor of bacterial HMG-CoA reductases will be instrumental in lead optimization and development of novel antibacterial drug candidates.
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Affiliation(s)
- Sucharita Bose
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA
- Institute for Stem Cell Science and Regenerative Medicine, GKVK Post Bellary Road, Bangalore, 560065, India
| | - C Nicklaus Steussy
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA
| | - Daneli López-Pérez
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907, USA
- Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Tim Schmidt
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA
| | - Samadhi C Kulathunga
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA
| | - Mohamed N Seleem
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, IN, 47907, USA
- Department of Biomedical Sciences and Pathobiology, VA-MD College of Veterinary Medicine, Virginia Tech, 205 Duck Pond Drive, Blacksburg, VA, 24061, USA
| | - Mark Lipton
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907, USA
| | - Andrew D Mesecar
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA
- Department of Biochemistry, Purdue University, 175 South University Street, West Lafayette, IN, 47907, USA
| | - Victor W Rodwell
- Department of Biochemistry, Purdue University, 175 South University Street, West Lafayette, IN, 47907, USA
| | - Cynthia V Stauffacher
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA.
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4
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Yu Y, Wang J. Anti-HMG-CoA reductase, antioxidant, anti-urease potentials, and anti-leukemia properties of 4-Butylresorcinol as a potential treatment for hypercholesterolemia. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2022. [DOI: 10.1080/10942912.2022.2115062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Yanli Yu
- Department of Blood Transfusion, NO. 215 Hospital of Shaanxi Nuclear Industry, Xianyang, SN, China
| | - JianJun Wang
- Department of Medical Examination, NO. 215 Hospital of Shaanxi Nuclear Industry, Xianyang, SN, China
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5
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Haywood J, Breese KJ, Zhang J, Waters MT, Bond CS, Stubbs KA, Mylne JS. A fungal tolerance trait and selective inhibitors proffer HMG-CoA reductase as a herbicide mode-of-action. Nat Commun 2022; 13:5563. [PMID: 36137996 PMCID: PMC9500038 DOI: 10.1038/s41467-022-33185-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 09/07/2022] [Indexed: 12/02/2022] Open
Abstract
Decades of intense herbicide use has led to resistance in weeds. Without innovative weed management practices and new herbicidal modes of action, the unabated rise of herbicide resistance will undoubtedly place further stress upon food security. HMGR (3-hydroxy-3-methylglutaryl-coenzyme A reductase) is the rate limiting enzyme of the eukaryotic mevalonate pathway successfully targeted by statins to treat hypercholesterolemia in humans. As HMGR inhibitors have been shown to be herbicidal, HMGR could represent a mode of action target for the development of herbicides. Here, we present the crystal structure of a HMGR from Arabidopsis thaliana (AtHMG1) which exhibits a wider active site than previously determined structures from different species. This plant conserved feature enables the rational design of specific HMGR inhibitors and we develop a tolerance trait through sequence analysis of fungal gene clusters. These results suggest HMGR to be a viable herbicide target modifiable to provide a tolerance trait. Managing herbicide resistance problem needs the identification of new herbicidal modes of action. Here, the authors solve the crystal structures of Arabidopsis HMGR and show HMGR as a potential new herbicide target by identifying plant-specific HMGR inhibitors and engineering tolerant trait in Arabidopsis.
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Affiliation(s)
- Joel Haywood
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, Perth, WA, 6102, Australia. .,School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, 6009, Australia.
| | - Karen J Breese
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, 6009, Australia
| | - Jingjing Zhang
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, 6009, Australia
| | - Mark T Waters
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, 6009, Australia
| | - Charles S Bond
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, 6009, Australia
| | - Keith A Stubbs
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, 6009, Australia
| | - Joshua S Mylne
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, Perth, WA, 6102, Australia. .,School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, 6009, Australia.
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6
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Gesto DS, Pereira CMS, Cerqueira NMFS, Sousa SF. An Atomic-Level Perspective of HMG-CoA-Reductase: The Target Enzyme to Treat Hypercholesterolemia. Molecules 2020; 25:molecules25173891. [PMID: 32859023 PMCID: PMC7503714 DOI: 10.3390/molecules25173891] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/23/2020] [Accepted: 08/24/2020] [Indexed: 12/19/2022] Open
Abstract
This review provides an updated atomic-level perspective regarding the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR), linking the more recent data on this enzyme with a structure/function interpretation. This enzyme catalyzes one of the most important steps in cholesterol biosynthesis and is regarded as one of the most important drug targets in the treatment of hypercholesterolemia. Taking this into consideration, we review in the present article several aspects of this enzyme, including its structure and biochemistry, its catalytic mechanism and different reported and proposed approaches for inhibiting this enzyme, including the commercially available statins or the possibility of using dimerization inhibitors.
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Affiliation(s)
- Diana S. Gesto
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal;
| | - Carlos M. S. Pereira
- UCIBIO/REQUIMTE, BioSIM, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; (C.M.S.P.); (N.M.F.S.C.)
| | - Nuno M. F. S. Cerqueira
- UCIBIO/REQUIMTE, BioSIM, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; (C.M.S.P.); (N.M.F.S.C.)
| | - Sérgio F. Sousa
- UCIBIO/REQUIMTE, BioSIM, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; (C.M.S.P.); (N.M.F.S.C.)
- Correspondence:
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7
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Peacock RB, Hicks CW, Walker AM, Dewing SM, Lewis KM, Abboud JC, Stewart SWA, Kang C, Watson JM. Structural and Functional Characterization of Dynamic Oligomerization in Burkholderia cenocepacia HMG-CoA Reductase. Biochemistry 2019; 58:3960-3970. [PMID: 31469273 DOI: 10.1021/acs.biochem.9b00494] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGR), in most organisms, catalyzes the four-electron reduction of the thioester (S)-HMG-CoA to the primary alcohol (R)-mevalonate, utilizing NADPH as the hydride donor. In some organisms, including the opportunistic lung pathogen Burkholderia cenocepacia, it catalyzes the reverse reaction, utilizing NAD+ as a hydride acceptor in the oxidation of mevalonate. B. cenocepacia HMGR has been previously shown to exist as an ensemble of multiple non-additive oligomeric states, each with different levels of enzymatic activity, suggesting that the enzyme exhibits characteristics of the morpheein model of allostery. We have characterized a number of factors, including pH, substrate concentration, and enzyme concentration, that modulate the structural transitions that influence the interconversion among the multiple oligomers. We have also determined the crystal structure of B. cenocepacia HMGR in the hexameric state bound to coenzyme A and ADP. This hexameric assembly provides important clues about how the transition among oligomers might occur, and why B. cenocepacia HMGR, unique among characterized HMGRs, exhibits morpheein-like behavior.
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Affiliation(s)
- Riley B Peacock
- Department of Chemistry and Biochemistry , Gonzaga University , Spokane , Washington 99258 , United States
| | - Chad W Hicks
- Department of Chemistry and Biochemistry , Gonzaga University , Spokane , Washington 99258 , United States
| | - Alexander M Walker
- Department of Chemistry , Washington State University , Pullman , Washington 99164 , United States
| | - Sophia M Dewing
- Department of Chemistry and Biochemistry , Gonzaga University , Spokane , Washington 99258 , United States
| | - Kevin M Lewis
- Department of Chemistry , Washington State University , Pullman , Washington 99164 , United States
| | - Jean-Claude Abboud
- Department of Chemistry and Biochemistry , Gonzaga University , Spokane , Washington 99258 , United States
| | - Samuel W A Stewart
- Department of Chemistry and Biochemistry , Gonzaga University , Spokane , Washington 99258 , United States
| | - ChulHee Kang
- Department of Chemistry , Washington State University , Pullman , Washington 99164 , United States
| | - Jeffrey M Watson
- Department of Chemistry and Biochemistry , Gonzaga University , Spokane , Washington 99258 , United States
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8
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Ragwan ER, Arai E, Kung Y. New Crystallographic Snapshots of Large Domain Movements in Bacterial 3-Hydroxy-3-methylglutaryl Coenzyme A Reductase. Biochemistry 2018; 57:5715-5725. [PMID: 30199631 DOI: 10.1021/acs.biochem.8b00869] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGR) catalyzes the first committed step of the mevalonate pathway, which is used across biology in the biosynthesis of countless metabolites. HMGR consumes 2 equiv of the cofactor NAD(P)H to perform the four-electron reduction of HMG-CoA to mevalonate toward the production of steroids and isoprenoids, the largest class of natural products. Recent structural data have shown that HMGR contains a highly mobile C-terminal domain (CTD) that is believed to adopt many different conformations to permit binding and dissociation of the substrate, cofactors, and products at specific points during the reaction cycle. Here, we have characterized the HMGR from Delftia acidovorans as an NADH-specific enzyme and determined crystal structures of the enzyme in unbound, mevalonate-bound, and NADH- and citrate-bound states. Together, these structures depict ligand binding in both the active site and the cofactor-binding site while illustrating how a conserved helical motif confers NAD(P)H cofactor specificity. Unexpectedly, the NADH-bound structure also reveals a new conformation of the CTD, in which the domain has "flipped" upside-down, while directly binding the cofactor. By capturing these structural snapshots, this work not only expands the known range of HMGR domain movement but also provides valuable insight into the catalytic mechanism of this biologically important enzyme.
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Affiliation(s)
- Edwin R Ragwan
- Department of Chemistry , Bryn Mawr College , 101 North Merion Avenue , Bryn Mawr , Pennsylvania 19010 , United States
| | - Eri Arai
- Department of Chemistry , Bryn Mawr College , 101 North Merion Avenue , Bryn Mawr , Pennsylvania 19010 , United States
| | - Yan Kung
- Department of Chemistry , Bryn Mawr College , 101 North Merion Avenue , Bryn Mawr , Pennsylvania 19010 , United States
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9
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Miller BR, Kung Y. Structural Features and Domain Movements Controlling Substrate Binding and Cofactor Specificity in Class II HMG-CoA Reductase. Biochemistry 2017; 57:654-662. [PMID: 29224355 DOI: 10.1021/acs.biochem.7b00999] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The key mevalonate pathway enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGR) uses the cofactor NAD(P)H to reduce HMG-CoA to mevalonate in the production of countless metabolites and natural products. Although inhibition of HMGR by statin drugs is well-understood, several mechanistic details of HMGR catalysis remain unresolved, and the structural basis for the wide range of cofactor specificity for either NADH or NADPH among HMGRs from different organisms is also unknown. Here, we present crystal structures of HMGR from Streptococcus pneumoniae (SpHMGR) alongside kinetic data of the enzyme's cofactor preferences. Our structure of SpHMGR bound with its kinetically preferred NADPH cofactor suggests how NADPH-specific binding and recognition are achieved. In addition, our structure of HMG-CoA-bound SpHMGR reveals large, previously unknown conformational domain movements that may control HMGR substrate binding and enable cofactor exchange without intermediate release during the catalytic cycle. Taken together, this work provides critical new insights into both the HMGR reaction mechanism and the structural basis of cofactor specificity.
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Affiliation(s)
- Bradley R Miller
- Department of Chemistry, Bryn Mawr College , 101 North Merion Avenue, Bryn Mawr, Pennsylvania 19010, United States
| | - Yan Kung
- Department of Chemistry, Bryn Mawr College , 101 North Merion Avenue, Bryn Mawr, Pennsylvania 19010, United States
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10
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Oliveira EF, Cerqueira NMFSA, Ramos MJ, Fernandes PA. QM/MM study of the mechanism of reduction of 3-hydroxy-3-methylglutaryl coenzyme A catalyzed by human HMG-CoA reductase. Catal Sci Technol 2016. [DOI: 10.1039/c6cy00356g] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Detailing with atomistic resolution the reaction mechanism of human HMG-CoA reductase (HMG-CoA-R) might provide valuable insights for the development of new cholesterol-lowering drugs.
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Affiliation(s)
- Eduardo F. Oliveira
- REQUIMTE
- Departamento de Química e Bioquímica
- Faculdade de Ciências
- Universidade do Porto
- 4169-007 Porto
| | | | - Maria J. Ramos
- REQUIMTE
- Departamento de Química e Bioquímica
- Faculdade de Ciências
- Universidade do Porto
- 4169-007 Porto
| | - Pedro A. Fernandes
- REQUIMTE
- Departamento de Química e Bioquímica
- Faculdade de Ciências
- Universidade do Porto
- 4169-007 Porto
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11
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De Ita JR, Castilla-Cortázar I, Aguirre GA, Sánchez-Yago C, Santos-Ruiz MO, Guerra-Menéndez L, Martín-Estal I, García-Magariño M, Lara-Díaz VJ, Puche JE, Muñoz U. Altered liver expression of genes involved in lipid and glucose metabolism in mice with partial IGF-1 deficiency: an experimental approach to metabolic syndrome. J Transl Med 2015; 13:326. [PMID: 26467524 PMCID: PMC4604722 DOI: 10.1186/s12967-015-0684-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/01/2015] [Indexed: 12/18/2022] Open
Abstract
Background Insulin growth factor 1 (IGF-1) has multiple effects on metabolism. Much evidence suggests that the deficiency of this hormone increases insulin resistance, impairs lipid metabolism, augments oxidative damage and deregulates the neuro-hormonal axis. An inverse relationship between IGF-1 levels and the prevalence of Metabolic Syndrome (MetS) with its cardiovascular complications has been identified. However, the underlying mechanisms linking IGF-1 and MetS are still poorly understood. In order to elucidate such mechanisms, the aim of this work was to study, in mice with partial IGF-1 deficiency, liver expression of genes involved in glucose and lipid metabolism as well as serum levels of glucose, triglycerides and cholesterol, as well as liver malondialdehyde (MDA) levels, as a marker for oxidative damage. Methods Three experimental groups were studied in parallel: Controls (CO), wild type mice (igf-1+/+); untreated heterozygous mice (Hz, igf-1+/−) and Hz (igf-1+/−) mice treated with low doses of IGF-1 for 10 days (Hz + IGF-1). Results A reduction of IGF-1 serum levels in the Hz group was found, which was normalized by IGF-1 therapy. Serum levels of glucose, triglycerides and cholesterol were significantly increased in the untreated Hz group as compared to both controls and Hz + IGF-1 groups. The expression of genes involved in gluconeogenesis, glycogenolysis, lipid synthesis and transport, and catabolism were altered in untreated Hz animals and the expression of most of them was normalized by IGF-1 therapy; MDA was also significantly increased in the Hz untreated group. Conclusions The mere partial IGF-1 deficiency is responsible for the reduction in the expression of genes involved in glucose and lipid metabolism, resulting in dyslipidemia and hyperglycemia. Such genetic alterations may seriously contribute to the establishment of MetS.
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Affiliation(s)
- J Rodríguez De Ita
- Escuela de Medicina, Tecnologico de Monterrey, Avenida Morones Prieto No. 3000 Pte. Col. Los Doctores, 64710, Monterrey, Nuevo León, México.
| | - I Castilla-Cortázar
- Escuela de Medicina, Tecnologico de Monterrey, Avenida Morones Prieto No. 3000 Pte. Col. Los Doctores, 64710, Monterrey, Nuevo León, México. .,Fundación de Investigación HM Hospitales, Plaza. del Conde del Valle de Súchil 16, 28015, Madrid, Spain.
| | - G A Aguirre
- Escuela de Medicina, Tecnologico de Monterrey, Avenida Morones Prieto No. 3000 Pte. Col. Los Doctores, 64710, Monterrey, Nuevo León, México.
| | - C Sánchez-Yago
- Department of Medical Physiology, Institute of Applied Molecular Medicine (IMMA), School of Medicine, University CEU San Pablo, Calle Boadilla del Monte s/n, km 5,3, 28668, Madrid, Spain.
| | - M Olleros Santos-Ruiz
- Fundación de Investigación HM Hospitales, Plaza. del Conde del Valle de Súchil 16, 28015, Madrid, Spain.
| | - L Guerra-Menéndez
- Department of Medical Physiology, Institute of Applied Molecular Medicine (IMMA), School of Medicine, University CEU San Pablo, Calle Boadilla del Monte s/n, km 5,3, 28668, Madrid, Spain.
| | - I Martín-Estal
- Escuela de Medicina, Tecnologico de Monterrey, Avenida Morones Prieto No. 3000 Pte. Col. Los Doctores, 64710, Monterrey, Nuevo León, México.
| | - M García-Magariño
- Escuela de Medicina, Tecnologico de Monterrey, Avenida Morones Prieto No. 3000 Pte. Col. Los Doctores, 64710, Monterrey, Nuevo León, México.
| | - V J Lara-Díaz
- Escuela de Medicina, Tecnologico de Monterrey, Avenida Morones Prieto No. 3000 Pte. Col. Los Doctores, 64710, Monterrey, Nuevo León, México.
| | - J E Puche
- Department of Medical Physiology, Institute of Applied Molecular Medicine (IMMA), School of Medicine, University CEU San Pablo, Calle Boadilla del Monte s/n, km 5,3, 28668, Madrid, Spain.
| | - U Muñoz
- Department of Medical Physiology, Institute of Applied Molecular Medicine (IMMA), School of Medicine, University CEU San Pablo, Calle Boadilla del Monte s/n, km 5,3, 28668, Madrid, Spain.
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12
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Haines BE, Wiest O, Stauffacher CV. The increasingly complex mechanism of HMG-CoA reductase. Acc Chem Res 2013; 46:2416-26. [PMID: 23898905 DOI: 10.1021/ar3003267] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
HMG-CoA reductase (HMGR) is the target of statins, cholesterol-lowering drugs prescribed to millions of patients worldwide. More recent research indicates that HMGR could be a useful target in the development of antimicrobial agents. Over the last seven decades, researchers have proposed a series of increasingly complex reaction mechanisms for this biomedically important enzyme. The maturation of the mechanistic proposals for HMGR have paralleled advances in a diverse set of research areas, such as molecular biology and computational chemistry. Thus, the development of the HMGR mechanism provides a useful case study for following the advances in state-of-the-art methods in enzyme mechanism research. Similarly, the questions raised by these mechanism proposals reflect the limitations of the methods used to develop them. The mechanism of HMGR, a four-electron oxidoreductase, is unique and far more complex than originally thought. The reaction contains multiple chemical steps, coupled to large-scale domain motions of the homodimeric enzyme. The first proposals for the HMGR mechanism were based on kinetic and labeling experiments, drawing analogies to the mechanism of known dehydrogenases. Advances in molecular biology and bioinformatics enabled researchers to use site-directed mutagenesis experiments and protein sequencing to identify catalytically important glutamate, aspartate, and histidine residues. These studies, in turn, have generated new and more complicated mechanistic proposals. With the development of protein crystallography, researchers solved HMGR crystal structures to reveal an unexpected lysine residue at the center of the active site. The many crystal structures of HMGR led to increasingly complex mechanistic proposals, but the inherent limitations of the protein crystallography left a number of questions unresolved. For example, the protonation state of the glutamate residue within the active site cannot be clearly determined from the crystal structure. The differing protonation state of this residue leads to different proposed mechanisms for the enzyme. As computational analysis of large biomolecules has become more feasible, the application of methods such as hybrid quantum mechanics/molecular mechanics (QM/MM) calculations to the HMGR mechanism have led to the most detailed mechanistic proposal yet. As these methodologies continue to improve, they prove to be very powerful for the study of enzyme mechanisms in conjunction with protein crystallography. Nevertheless, even the most current mechanistic proposal for HMGR remains incomplete due to limitations of the current computational methodologies. Thus, HMGR serves as a model for how the combination of increasingly sophisticated experimental and computational methods can elucidate very complex enzyme mechanisms.
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Affiliation(s)
- Brandon E. Haines
- Department of Chemistry and Biochemistry, Notre Dame University, Notre Dame, Indiana 46556, United States
| | - Olaf Wiest
- Department of Chemistry and Biochemistry, Notre Dame University, Notre Dame, Indiana 46556, United States
| | - Cynthia V. Stauffacher
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States
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