1
|
Gemmecker Y, Winiarska A, Hege D, Kahnt J, Seubert A, Szaleniec M, Heider J. A pH-dependent shift of redox cofactor specificity in a benzyl alcohol dehydrogenase of aromatoleum aromaticum EbN1. Appl Microbiol Biotechnol 2024; 108:410. [PMID: 38976076 PMCID: PMC11231019 DOI: 10.1007/s00253-024-13225-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 07/09/2024]
Abstract
We characterise a reversible bacterial zinc-containing benzyl alcohol dehydrogenase (BaDH) accepting either NAD+ or NADP+ as a redox cofactor. Remarkably, its redox cofactor specificity is pH-dependent with the phosphorylated cofactors favored at lower and the dephospho-forms at higher pH. BaDH also shows different steady-state kinetic behavior with the two cofactor forms. From a structural model, the pH-dependent shift may affect the charge of a histidine in the 2'-phosphate-binding pocket of the redox cofactor binding site. The enzyme is phylogenetically affiliated to a new subbranch of the Zn-containing alcohol dehydrogenases, which share this conserved residue. BaDH appears to have some specificity for its substrate, but also turns over many substituted benzyl alcohol and benzaldehyde variants, as well as compounds containing a conjugated C=C double bond with the aldehyde carbonyl group. However, compounds with an sp3-hybridised C next to the alcohol/aldehyde group are not or only weakly turned over. The enzyme appears to contain a Zn in its catalytic site and a mixture of Zn and Fe in its structural metal-binding site. Moreover, we demonstrate the use of BaDH in an enzyme cascade reaction with an acid-reducing tungsten enzyme to reduce benzoate to benzyl alcohol. KEY POINTS: •Zn-containing BaDH has activity with either NAD + or NADP+ at different pH optima. •BaDH converts a broad range of substrates. •BaDH is used in a cascade reaction for the reduction of benzoate to benzyl alcohol.
Collapse
Affiliation(s)
- Yvonne Gemmecker
- Laboratory for Microbial Biochemistry, Philipps University of Marburg, 35043, Marburg, Germany
| | - Agnieszka Winiarska
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239, Krakow, Poland
| | - Dominik Hege
- Laboratory for Microbial Biochemistry, Philipps University of Marburg, 35043, Marburg, Germany
| | - Jörg Kahnt
- Mass Spectrometry and Proteomics, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Andreas Seubert
- Faculty of Chemistry, Analytical Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Maciej Szaleniec
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239, Krakow, Poland.
| | - Johann Heider
- Laboratory for Microbial Biochemistry, Philipps University of Marburg, 35043, Marburg, Germany.
- Center for Synthetic Microbiology, Marburg, Germany.
| |
Collapse
|
2
|
Hagedoorn PL, Pabst M, Hanefeld U. The metal cofactor: stationary or mobile? Appl Microbiol Biotechnol 2024; 108:391. [PMID: 38910188 PMCID: PMC11194214 DOI: 10.1007/s00253-024-13206-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/22/2024] [Accepted: 05/27/2024] [Indexed: 06/25/2024]
Abstract
Metal cofactors are essential for catalysis and enable countless conversions in nature. Interestingly, the metal cofactor is not always static but mobile with movements of more than 4 Å. These movements of the metal can have different functions. In the case of the xylose isomerase and medium-chain dehydrogenases, it clearly serves a catalytic purpose. The metal cofactor moves during substrate activation and even during the catalytic turnover. On the other hand, in class II aldolases, the enzymes display resting states and active states depending on the movement of the catalytic metal cofactor. This movement is caused by substrate docking, causing the metal cofactor to take the position essential for catalysis. As these metal movements are found in structurally and mechanistically unrelated enzymes, it has to be expected that this metal movement is more common than currently perceived. KEY POINTS: • Metal ions are essential cofactors that can move during catalysis. • In class II aldolases, the metal cofactors can reside in a resting state and an active state. • In MDR, the movement of the metal cofactor is essential for substrate docking.
Collapse
Affiliation(s)
- Peter-Leon Hagedoorn
- Afdeling Biotechnologie, Technische Universiteit Delft, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands
| | - Martin Pabst
- Afdeling Biotechnologie, Technische Universiteit Delft, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands
| | - Ulf Hanefeld
- Afdeling Biotechnologie, Technische Universiteit Delft, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands.
| |
Collapse
|
3
|
Jacobi T, Kratzer DA, Plapp BV. Substitution of both histidines in the active site of yeast alcohol dehydrogenase 1 exposes underlying pH dependencies. Chem Biol Interact 2024; 394:110992. [PMID: 38579923 PMCID: PMC11090211 DOI: 10.1016/j.cbi.2024.110992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/13/2024] [Accepted: 04/02/2024] [Indexed: 04/07/2024]
Abstract
Histidine residues 44 and 48 in yeast alcohol dehydrogenase (ADH) bind to the coenzymes NAD(H) and contribute to catalysis. The individual H44R and H48Q substitutions alter the kinetics and pH dependencies, and now the roles of other ionizable groups in the enzyme were studied in the doubly substituted H44R/H48Q ADH. The substitutions make the enzyme more resistant to inactivation by diethyl pyrocarbonate, modestly improve affinity for coenzymes, and substantially decrease catalytic efficiencies for ethanol oxidation and acetaldehyde reduction. The pH dependencies for several kinetic parameters are shifted from pK values for wild-type ADH of 7.3-8.1 to values for H44R/H48Q ADH of 8.0-9.6, and are assigned to the water or alcohol bound to the catalytic zinc. It appears that the rate of binding of NAD+ is electrostatically favored with zinc-hydroxide whereas binding of NADH is faster with neutral zinc-water. The pH dependencies of catalytic efficiencies (V/EtKm) for ethanol oxidation and acetaldehyde reduction are similarly controlled by deprotonation and protonation, respectively. The substitutions make an enzyme that resembles the homologous horse liver H51Q ADH, which has Arg-47 and Gln-51 and exhibits similar pK values. In the wild-type ADHs, it appears that His-48 (or His-51) in the proton relay systems linked to the catalytic zinc ligands modulate catalytic efficiencies.
Collapse
Affiliation(s)
- Tobias Jacobi
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Darla Ann Kratzer
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA.
| | - Bryce V Plapp
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA.
| |
Collapse
|
4
|
Maret W. Chemistry meets biology in the coordination dynamics of metalloproteins. J Inorg Biochem 2024; 251:112431. [PMID: 38016325 DOI: 10.1016/j.jinorgbio.2023.112431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/10/2023] [Accepted: 11/14/2023] [Indexed: 11/30/2023]
Abstract
Metal sites in proteins are often presented in an idealized way that does not capture the intrinsic dynamic behavior of the protein or the extrinsic factors that affect changes in the coordination of the metal ion in biological space and time. The bioinorganic chemistry possible in healthy and diseased living organisms is limited by prevailing pH values, redox potentials, and availability and concentrations of metal ions and ligands. Changes in any of these parameters and protein-protein or protein-ligand interactions can result in differences in the type of metal ion bound, metal occupancy, and coordination number or geometry. This article addresses the plasticity and complexity of metal coordination in proteins when these parameters are considered. It uses three examples of zinc sites with sulfur donor atoms from cysteines in mammalian proteins: alcohol dehydrogenases, metallothioneins, and zinc transporters of the ZnT (SLC30A) family. Coordination dynamics of the metal sites in these proteins has different purposes; in alcohol dehydrogenases for the metal ion to perform its different roles in the catalytic cycle, in metallothioneins for serving as a metal buffer, and in ZnT zinc transporters for sensing metal ions and moving them through the protein and thus biological membranes. Defining the biological and chemical parameters that determine and affect coordination dynamics of metal ions in proteins will inform future investigations of metalloproteins.
Collapse
Affiliation(s)
- Wolfgang Maret
- Departments of Biochemistry and Nutritional Sciences, School of Life Course and Population Sciences, Faculty of Life Sciences and Medicine, King's College London, London SE1 9NH, UK.
| |
Collapse
|
5
|
Zheng C, Ji Z, Mathews II, Boxer SG. Enhanced active-site electric field accelerates enzyme catalysis. Nat Chem 2023; 15:1715-1721. [PMID: 37563323 PMCID: PMC10906027 DOI: 10.1038/s41557-023-01287-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/29/2023] [Indexed: 08/12/2023]
Abstract
The design and improvement of enzymes based on physical principles remain challenging. Here we demonstrate that the principle of electrostatic catalysis can be leveraged to substantially improve a natural enzyme's activity. We enhanced the active-site electric field in horse liver alcohol dehydrogenase by replacing the serine hydrogen-bond donor with threonine and replacing the catalytic Zn2+ with Co2+. Based on the electric field enhancement, we make a quantitative prediction of rate acceleration-50-fold faster than the wild-type enzyme-which was in close agreement with experimental measurements. The effects of the hydrogen bonding and metal coordination, two distinct chemical forces, are described by a unified physical quantity-electric field, which is quantitative, and shown here to be additive and predictive. These results suggest a new design paradigm for both biological and non-biological catalysts.
Collapse
Affiliation(s)
- Chu Zheng
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Zhe Ji
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | | | - Steven G Boxer
- Department of Chemistry, Stanford University, Stanford, CA, USA.
| |
Collapse
|
6
|
Plapp BV, Kratzer DA, Souhrada SK, Warth E, Jacobi T. Specific base catalysis by yeast alcohol dehydrogenase I with substitutions of histidine-48 by glutamate or serine residues in the proton relay system. Chem Biol Interact 2023; 382:110558. [PMID: 37247811 PMCID: PMC10527620 DOI: 10.1016/j.cbi.2023.110558] [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: 04/05/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 05/31/2023]
Abstract
His-48 in yeast alcohol dehydrogenase I (His 51 in horse liver alcohol dehydrogenase) is a highly conserved residue in the active sites of many alcohol dehydrogenases. The imidazole group of His-48 may participate in base catalysis of proton transfer as it is linked by hydrogen bonds through the 2'-hydroxyl group of the nicotinamide ribose and the hydroxyl group of Thr-45 to the hydroxyl group of the alcohol bound to the catalytic zinc. In this study, His-48 was substituted with a glutamic acid residue to determine if a carboxylate could replace imidazole or to a serine residue to determine if the exposure of the 2'-hydroxyl group of the ribose to solvent would allow proton transfer to water without base catalysis. At pH 7.3, the H48E substitution increases affinity for NAD+ and NADH 17- or 2.6-fold, but decreases catalytic efficiency (V/Km) on ethanol by 70-fold and on acetaldehyde by 6-fold relative to wild-type enzyme. The H48S substitution increases affinity for coenzymes by 2-fold and decreases (V/Km) on ethanol and acetaldehyde only by ∼3-fold. The substituted enzymes show substrate deuterium isotope (H/D) effects of 3-4 for turnover number (V1) and catalytic efficiency (V1/Kb) for ethanol oxidation, indicating that hydrogen transfer is partially rate-limiting and suggesting a somewhat more random mechanism for binding of ethanol and NAD+. For reduction of acetaldehyde, the deuterium isotope effects are small, and the kinetic mechanism appears to be ordered for binding of NADH first and acetaldehyde next. The pH dependencies for H48E and H48S ADHs can be described by a mechanism with pK values of about 6-7 and 9. However, the pH dependencies for oxidation of ethanol and butanol by the H48S enzyme are also simply described by a straight line, with slopes of log V1/Kb against pH of 0.37 or 0.43, respectively. The linear dependence apparently represents catalysis by hydroxide that has a low activity coefficient due to the protein environment, or to a kinetically complex proton transfer. The effects of the substitutions of His-48 show that this residue contributes to catalysis, although many dehydrogenases also have other residues.
Collapse
Affiliation(s)
- Bryce V Plapp
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA, 52242, USA.
| | - Darla Ann Kratzer
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA, 52242, USA.
| | - Susan K Souhrada
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA, 52242, USA.
| | - Edda Warth
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA, 52242, USA.
| | - Tobias Jacobi
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA, 52242, USA.
| |
Collapse
|
7
|
Kasamatsu S, Nishimura A, Alam MM, Morita M, Shimoda K, Matsunaga T, Jung M, Ogata S, Barayeu U, Ida T, Nishida M, Nishimura A, Motohashi H, Akaike T. Supersulfide catalysis for nitric oxide and aldehyde metabolism. SCIENCE ADVANCES 2023; 9:eadg8631. [PMID: 37595031 PMCID: PMC10438454 DOI: 10.1126/sciadv.adg8631] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 07/19/2023] [Indexed: 08/20/2023]
Abstract
Abundant formation of endogenous supersulfides, which include reactive persulfide species and sulfur catenated residues in thiols and proteins (supersulfidation), has been observed. We found here that supersulfides catalyze S-nitrosoglutathione (GSNO) metabolism via glutathione-dependent electron transfer from aldehydes by exploiting alcohol dehydrogenase 5 (ADH5). ADH5 is a highly conserved bifunctional enzyme serving as GSNO reductase (GSNOR) that down-regulates NO signaling and formaldehyde dehydrogenase (FDH) that detoxifies formaldehyde in the form of glutathione hemithioacetal. C174S mutation significantly reduced the supersulfidation of ADH5 and almost abolished GSNOR activity but spared FDH activity. Notably, Adh5C174S/C174S mice manifested improved cardiac functions possibly because of GSNOR elimination and consequent increased NO bioavailability. Therefore, we successfully separated dual functions (GSNOR and FDH) of ADH5 (mediated by the supersulfide catalysis) through the biochemical analysis for supersulfides in vitro and characterizing in vivo phenotypes of the GSNOR-deficient organisms that we established herein. Supersulfides in ADH5 thus constitute a substantial catalytic center for GSNO metabolism mediating electron transfer from aldehydes.
Collapse
Affiliation(s)
- Shingo Kasamatsu
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
- Department of Biological Chemistry, Graduate School of Science, Osaka Metropolitan University, Osaka 599-8531, Japan
| | - Akira Nishimura
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara 630-0192, Japan
| | - Md. Morshedul Alam
- Department of Gene Expression Regulation, IDAC, Tohoku University, Sendai 980-8575, Japan
- Department of Genetic Engineering and Biotechnology, Bangabandhu Sheikh Mujibur Rahman Maritime University, Mirpur 12, Dhaka 1216, Bangladesh
| | - Masanobu Morita
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Kakeru Shimoda
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Cardiocirculatory Dynamism Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
| | - Tetsuro Matsunaga
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Minkyung Jung
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Seiryo Ogata
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Uladzimir Barayeu
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Tomoaki Ida
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Motohiro Nishida
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Cardiocirculatory Dynamism Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Department of Physiology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Akiyuki Nishimura
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Cardiocirculatory Dynamism Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
| | - Hozumi Motohashi
- Department of Gene Expression Regulation, IDAC, Tohoku University, Sendai 980-8575, Japan
| | - Takaaki Akaike
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| |
Collapse
|
8
|
Blacker TS, Duchen MR, Bain AJ. NAD(P)H binding configurations revealed by time-resolved fluorescence and two-photon absorption. Biophys J 2023; 122:1240-1253. [PMID: 36793214 PMCID: PMC10111271 DOI: 10.1016/j.bpj.2023.02.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 09/07/2022] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
NADH and NADPH play key roles in the regulation of metabolism. Their endogenous fluorescence is sensitive to enzyme binding, allowing changes in cellular metabolic state to be determined using fluorescence lifetime imaging microscopy (FLIM). However, to fully uncover the underlying biochemistry, the relationships between their fluorescence and binding dynamics require greater understanding. Here we accomplish this through time- and polarization-resolved fluorescence and polarized two-photon absorption measurements. Two lifetimes result from binding of both NADH to lactate dehydrogenase and NADPH to isocitrate dehydrogenase. The composite fluorescence anisotropy indicates the shorter (1.3-1.6 ns) decay component to be accompanied by local motion of the nicotinamide ring, pointing to attachment solely via the adenine moiety. For the longer lifetime (3.2-4.4 ns), the nicotinamide conformational freedom is found to be fully restricted. As full and partial nicotinamide binding are recognized steps in dehydrogenase catalysis, our results unify photophysical, structural, and functional aspects of NADH and NADPH binding and clarify the biochemical processes that underlie their contrasting intracellular lifetimes.
Collapse
Affiliation(s)
- Thomas S Blacker
- Department of Physics & Astronomy, University College London, London, United Kingdom; Research Department of Cell & Developmental Biology, University College London, London, United Kingdom
| | - Michael R Duchen
- Research Department of Cell & Developmental Biology, University College London, London, United Kingdom
| | - Angus J Bain
- Department of Physics & Astronomy, University College London, London, United Kingdom.
| |
Collapse
|
9
|
Taut J, Chambron J, Kersting B. Fifty Years of Inorganic Biomimetic Chemistry: From the Complexation of Single Metal Cations to Polynuclear Metal Complexes by Multidentate Thiolate Ligands. Eur J Inorg Chem 2023. [DOI: 10.1002/ejic.202200739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Affiliation(s)
- Josef Taut
- Institut für Anorganische Chemie Universität Leipzig Johannisallee 29 04103 Leipzig Germany
- Institut de Chimie de Strasbourg UMR 7177 CNRS-Université de Strasbourg 1, rue Blaise Pascal 67008 Strasbourg France
| | - Jean‐Claude Chambron
- Institut de Chimie de Strasbourg UMR 7177 CNRS-Université de Strasbourg 1, rue Blaise Pascal 67008 Strasbourg France
| | - Berthold Kersting
- Institut für Anorganische Chemie Universität Leipzig Johannisallee 29 04103 Leipzig Germany
| |
Collapse
|
10
|
Marrone A, Fish RH. Bioorganometallic Chemistry at the Interface with Biocatalysis: Chemoselective Reduction of Biomimetic NAD + Cofactors with [Cp*Rh(bpy)H] +, Tandem Catalysis with 1,4-NADH-Dependent Enzymes, Chiral Synthesis, Organotin Metabolites, and DFT Mechanism Studies. Organometallics 2023. [DOI: 10.1021/acs.organomet.2c00550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Affiliation(s)
- Alessandro Marrone
- Dipartimento di Farmacia, Università “G d’Annunzio”, di Chieti-Pescara 66100, Italy
| | - Richard H. Fish
- Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, United States
| |
Collapse
|
11
|
Bai X, Lan J, He S, Bu T, Zhang J, Wang L, Jin X, Mao Y, Guan W, Zhang L, Lu M, Piao H, Jo I, Quan C, Nam KH, Xu Y. Structural and Biochemical Analyses of the Butanol Dehydrogenase from Fusobacterium nucleatum. Int J Mol Sci 2023; 24:ijms24032994. [PMID: 36769315 PMCID: PMC9917632 DOI: 10.3390/ijms24032994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/19/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023] Open
Abstract
Butanol dehydrogenase (BDH) plays a significant role in the biosynthesis of butanol in bacteria by catalyzing butanal conversion to butanol at the expense of the NAD(P)H cofactor. BDH is an attractive enzyme for industrial application in butanol production; however, its molecular function remains largely uncharacterized. In this study, we found that Fusobacterium nucleatum YqdH (FnYqdH) converts aldehyde into alcohol by utilizing NAD(P)H, with broad substrate specificity toward aldehydes but not alcohols. An in vitro metal ion substitution experiment showed that FnYqdH has higher enzyme activity in the presence of Co2+. Crystal structures of FnYqdH, in its apo and complexed forms (with NAD and Co2+), were determined at 1.98 and 2.72 Å resolution, respectively. The crystal structure of apo- and cofactor-binding states of FnYqdH showed an open conformation between the nucleotide binding and catalytic domain. Key residues involved in the catalytic and cofactor-binding sites of FnYqdH were identified by mutagenesis and microscale thermophoresis assays. The structural conformation and preferred optimal metal ion of FnYqdH differed from that of TmBDH (homolog protein of FnYqdH). Overall, we proposed an alternative model for putative proton relay in FnYqdH, thereby providing better insight into the molecular function of BDH.
Collapse
Affiliation(s)
- Xue Bai
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Jing Lan
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Shanru He
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Tingting Bu
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Jie Zhang
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Lulu Wang
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
- School of Life Science and Biotechnology, Dalian University of Technology, No. 2 Linggong Road, Dalian 116024, China
| | - Xiaoling Jin
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Yuanchao Mao
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Wanting Guan
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Liying Zhang
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Ming Lu
- Shandong Provincial Key Laboratory of Energy Genetics, Key Laboratory of Biofuel, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
| | - Hailong Piao
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Inseong Jo
- Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Chunshan Quan
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Ki Hyun Nam
- Department of Life Science, Pohang University of Science and Technology, Pohang 35398, Republic of Korea
- POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 35398, Republic of Korea
- Correspondence: (K.H.N.); (Y.X.)
| | - Yongbin Xu
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
- Correspondence: (K.H.N.); (Y.X.)
| |
Collapse
|
12
|
Langley C, Tatsis E, Hong B, Nakamura Y, Paetz C, Stevenson CEM, Basquin J, Lawson DM, Caputi L, O'Connor SE. Expansion of the Catalytic Repertoire of Alcohol Dehydrogenases in Plant Metabolism. Angew Chem Int Ed Engl 2022; 61:e202210934. [PMID: 36198083 PMCID: PMC9828224 DOI: 10.1002/anie.202210934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Indexed: 11/19/2022]
Abstract
Medium-chain alcohol dehydrogenases (ADHs) comprise a highly conserved enzyme family that catalyse the reversible reduction of aldehydes. However, recent discoveries in plant natural product biosynthesis suggest that the catalytic repertoire of ADHs has been expanded. Here we report the crystal structure of dihydroprecondylocarpine acetate synthase (DPAS), an ADH that catalyses the non-canonical 1,4-reduction of an α,β-unsaturated iminium moiety. Comparison with structures of plant-derived ADHs suggest the 1,4-iminium reduction does not require a proton relay or the presence of a catalytic zinc ion in contrast to canonical 1,2-aldehyde reducing ADHs that require the catalytic zinc and a proton relay. Furthermore, ADHs that catalysed 1,2-iminium reduction required the presence of the catalytic zinc and the loss of the proton relay. This suggests how the ADH active site can be modified to perform atypical carbonyl reductions, providing insight into how chemical reactions are diversified in plant metabolism.
Collapse
Affiliation(s)
- Chloe Langley
- Department of Natural Product BiosynthesisMax Planck Institute for Chemical EcologyHans-Knöll Straße 8Jena07745Germany
| | - Evangelos Tatsis
- Chinese Academy of Sciences Centre for Excellence in Molecular Plant SciencesShanghai Institute of Plant Physiology and Ecology300 Feng Lin RoadShanghai200032China
| | - Benke Hong
- Department of Natural Product BiosynthesisMax Planck Institute for Chemical EcologyHans-Knöll Straße 8Jena07745Germany
| | - Yoko Nakamura
- Department of Natural Product BiosynthesisMax Planck Institute for Chemical EcologyHans-Knöll Straße 8Jena07745Germany,Research Group Biosynthesis and NMRMax Planck Institute for Chemical EcologyHans-Knöll Straße 8Jena07745Germany
| | - Christian Paetz
- Research Group Biosynthesis and NMRMax Planck Institute for Chemical EcologyHans-Knöll Straße 8Jena07745Germany
| | - Clare E. M. Stevenson
- Department of Biochemistry and MetabolismJohn Innes CentreNorwich Research ParkNorwichNR4 7UHUK
| | - Jerome Basquin
- Department of Structural Cell BiologyMax-Planck Institute for BiochemistryAm Klopferspitz 18, Martinsried82152PlaneggGermany
| | - David M. Lawson
- Department of Biochemistry and MetabolismJohn Innes CentreNorwich Research ParkNorwichNR4 7UHUK
| | - Lorenzo Caputi
- Department of Natural Product BiosynthesisMax Planck Institute for Chemical EcologyHans-Knöll Straße 8Jena07745Germany
| | - Sarah E. O'Connor
- Department of Natural Product BiosynthesisMax Planck Institute for Chemical EcologyHans-Knöll Straße 8Jena07745Germany
| |
Collapse
|
13
|
Plapp BV, Gakhar L, Subramanian R. Dependence of crystallographic atomic displacement parameters on temperature (25-150 K) for complexes of horse liver alcohol dehydrogenase. Acta Crystallogr D Struct Biol 2022; 78:1221-1234. [PMID: 36189742 PMCID: PMC9527765 DOI: 10.1107/s2059798322008361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/22/2022] [Indexed: 11/19/2022] Open
Abstract
Enzymes catalyze reactions by binding and orienting substrates with dynamic interactions. Horse liver alcohol dehydrogenase catalyzes hydrogen transfer with quantum-mechanical tunneling that involves fast motions in the active site. The structures and B factors of ternary complexes of the enzyme with NAD+ and 2,3,4,5,6-pentafluorobenzyl alcohol or NAD+ and 2,2,2-trifluoroethanol were determined to 1.1-1.3 Å resolution below the `glassy transition' in order to extract information about the temperature-dependent harmonic motions, which are reflected in the crystallographic B factors. The refinement statistics and structures are essentially the same for each structure at all temperatures. The B factors were corrected for a small amount of radiation decay. The overall B factors for the complexes are similar (13-16 Å2) over the range 25-100 K, but increase somewhat at 150 K. Applying TLS refinement to remove the contribution of pseudo-rigid-body displacements of coenzyme binding and catalytic domains provided residual B factors of 7-10 Å2 for the overall complexes and of 5-10 Å2 for C4N of NAD+ and the methylene carbon of the alcohols. These residual B factors have a very small dependence on temperature and include local harmonic motions and apparently contributions from other sources. Structures at 100 K show complexes that are poised for hydrogen transfer, which involves atomic displacements of ∼0.3 Å and is compatible with the motions estimated from the residual B factors and molecular-dynamics simulations. At 298 K local conformational changes are also involved in catalysis, as enzymes with substitutions of amino acids in the substrate-binding site have similar positions of NAD+ and pentafluorobenzyl alcohol and similar residual B factors, but differ by tenfold in the rate constants for hydride transfer.
Collapse
Affiliation(s)
- Bryce V. Plapp
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52252, USA
| | - Lokesh Gakhar
- Protein and Crystallography Facility, Carver College of Medicine, The University of Iowa, Iowa City, IA 52252, USA
| | - Ramaswamy Subramanian
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52252, USA
| |
Collapse
|
14
|
Dinh T, Rahn KT, Phillips RS. Crystallographic snapshots of ternary complexes of thermophilic secondary alcohol dehydrogenase from
Thermoanaerobacter pseudoethanolicus
reveal the dynamics of ligand exchange and the proton relay network. Proteins 2022; 90:1570-1583. [DOI: 10.1002/prot.26339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/16/2022] [Accepted: 03/27/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Tung Dinh
- Department of Chemistry University of Georgia Athens Georgia USA
| | - K. Troy Rahn
- Department of Chemistry University of Georgia Athens Georgia USA
| | - Robert S. Phillips
- Department of Chemistry University of Georgia Athens Georgia USA
- Department of Biochemistry and Molecular Biology University of Georgia Athens Georgia USA
- Center for Metalloenzyme Studies University of Georgia Athens Georgia USA
| |
Collapse
|
15
|
Zhang N, Bittner JP, Fiedler M, Beretta T, de María PD, Jakobtorweihen S, Kara S. Unraveling Alcohol Dehydrogenase Catalysis in Organic–Aqueous Biphasic Systems Combining Experiments and Molecular Dynamics Simulations. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ningning Zhang
- Biocatalysis and Bioprocessing Group, Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus, Denmark
| | - Jan Philipp Bittner
- Institute of Thermal Separation Processes, Hamburg University of Technology, Eißendorfer Straße 38, 21073 Hamburg, Germany
| | - Marius Fiedler
- Institute of Process Systems Engineering, Hamburg University of Technology, Am Schwarzenberg-Campus 4, 21073 Hamburg, Germany
| | - Thomas Beretta
- Biocatalysis and Bioprocessing Group, Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus, Denmark
| | - Pablo Domínguez de María
- Sustainable Momentum, SL, Av. Ansite 3, 4-6, 35011, Las Palmas de Gran Canaria, Canary Islands, Spain
| | - Sven Jakobtorweihen
- Institute of Thermal Separation Processes, Hamburg University of Technology, Eißendorfer Straße 38, 21073 Hamburg, Germany
- Institute of Chemical Reaction Engineering, Hamburg University of Technology, Eißendorfer Straße 38, 21073 Hamburg, Germany
| | - Selin Kara
- Biocatalysis and Bioprocessing Group, Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus, Denmark
- Institute of Technical Chemistry, Leibniz University Hannover, Callinstr. 5, 30167 Hannover, Germany
| |
Collapse
|
16
|
Rapp C, Nidetzky B. Hydride Transfer Mechanism of Enzymatic Sugar Nucleotide C2 Epimerization Probed with a Loose-Fit CDP-Glucose Substrate. ACS Catal 2022; 12:6816-6830. [PMID: 35747200 PMCID: PMC9207888 DOI: 10.1021/acscatal.2c00257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 05/12/2022] [Indexed: 11/29/2022]
Abstract
![]()
Transient oxidation–reduction
through hydride transfer with
tightly bound NAD coenzyme is used by a large class of sugar nucleotide
epimerases to promote configurational inversion of carbon stereocenters
in carbohydrate substrates. A requirement for the epimerases to coordinate
hydride abstraction and re-addition with substrate rotation in the
binding pocket poses a challenge for dynamical protein conformational
selection linked to enzyme catalysis. Here, we studied the thermophilic
C2 epimerase from Thermodesulfatator atlanticus (TaCPa2E) in combination with a slow CDP-glucose
substrate (kcat ≈ 1.0 min–1; 60 °C) to explore the sensitivity of the enzymatic hydride
transfer toward environmental fluctuations affected by temperature
(20–80 °C). We determined noncompetitive primary kinetic
isotope effects (KIE) due to 2H at the glucose C2 and showed
that a normal KIE on the kcat (Dkcat) reflects isotope sensitivity of
the hydrogen abstraction to enzyme-NAD+ in a rate-limiting
transient oxidation. The Dkcat peaked at 40 °C was 6.1 and decreased to 2.1 at low (20 °C)
and 3.3 at high temperature (80 °C). The temperature profiles
for kcat with the 1H and 2H substrate showed a decrease in the rate below a dynamically
important breakpoint (∼40 °C), suggesting an equilibrium
shift to an impaired conformational landscape relevant for catalysis
in the low-temperature region. Full Marcus-like model fits of the
rate and KIE profiles provided evidence for a high-temperature reaction
via low-frequency conformational sampling associated with a broad
distribution of hydride donor–acceptor distances (long-distance
population centered at 3.31 ± 0.02 Å), only poorly suitable
for quantum mechanical tunneling. Collectively, dynamical characteristics
of TaCPa2E-catalyzed hydride transfer during transient
oxidation of CDP-glucose reveal important analogies to mechanistically
simpler enzymes such as alcohol dehydrogenase and dihydrofolate reductase.
A loose-fit substrate (in TaCPa2E) resembles structural
variants of these enzymes by extensive dynamical sampling to balance
conformational flexibility and catalytic efficiency.
Collapse
Affiliation(s)
- Christian Rapp
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
- Austrian Centre of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz, Austria
| |
Collapse
|
17
|
Das S, Mondal R, Guin AK, Paul ND. Ligand centered redox enabled sustainable synthesis of triazines and pyrimidines using a zinc-stabilized azo-anion radical catalyst. Org Biomol Chem 2022; 20:3105-3117. [PMID: 35088804 DOI: 10.1039/d1ob02428k] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Herein, we report ligand-centered redox controlled Zn(II)-catalyzed multicomponent approaches for synthesizing pyrimidines and triazines. Taking advantage of the ligand-centered redox events and using a well-defined Zn(II)-catalyst (1a) bearing (E)-2-((4-chlorophenyl)diazenyl)-1,10-phenanthroline (L1a) as the redox-active ligand, a wide variety of substituted pyrimidines and triazines were prepared via dehydrogenative alcohol functionalization reactions. Pyrimidines were prepared via two pathways: (i) dehydrogenative coupling of primary and secondary alcohols with amidines and (ii) dehydrogenative coupling of primary alcohols with alkynes and amidines. Triazines were prepared via dehydrogenative coupling of alcohols and amidines. Catalyst 1a is well tolerant to a wide range of substrates yielding the desired pyrimidines and triazines in moderate to good isolated yields. A series of control reactions were performed to predict the plausible mechanism, suggesting that the active participation of the ligand-centered redox events enables the Zn(II)-complex 1a to act as an efficient catalyst for synthesizing these N-heterocycles. Electron transfer processes occur at the azo-aromatic ligand throughout the catalytic reaction, and the Zn(II)-center serves only as a template.
Collapse
Affiliation(s)
- Siuli Das
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Botanic Garden, Howrah 711103, India.
| | - Rakesh Mondal
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Botanic Garden, Howrah 711103, India.
| | - Amit Kumar Guin
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Botanic Garden, Howrah 711103, India.
| | - Nanda D Paul
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Botanic Garden, Howrah 711103, India.
| |
Collapse
|
18
|
Yang S, Miaskiewicz S, Bour C, Alix A, Gandon V. Transition structures for the oxy-ene reaction. Chem Commun (Camb) 2022; 58:4751-4754. [PMID: 35332901 DOI: 10.1039/d2cc00687a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An overlooked pericyclic reaction between allyl alcohols and alkenes to form carbonyl compounds is analyzed. It combines the characteristic features of the Alder-ene reaction and of the oxy-Cope rearrangement. This oxy-ene reaction could be involved in biosynthetic pathways.
Collapse
Affiliation(s)
- Shengwen Yang
- Université Paris-Saclay, CNRS, Institut de Chimie Moléculaire et des Matériaux d'Orsay, 91405, Orsay, France. .,Laboratoire de Chimie Moléculaire (LCM), CNRS UMR 9168, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91128 Palaiseau cedex, France
| | - Solène Miaskiewicz
- Université Paris-Saclay, CNRS, Institut de Chimie Moléculaire et des Matériaux d'Orsay, 91405, Orsay, France.
| | - Christophe Bour
- Université Paris-Saclay, CNRS, Institut de Chimie Moléculaire et des Matériaux d'Orsay, 91405, Orsay, France.
| | - Aurélien Alix
- Université Paris-Saclay, CNRS, Institut de Chimie Moléculaire et des Matériaux d'Orsay, 91405, Orsay, France.
| | - Vincent Gandon
- Université Paris-Saclay, CNRS, Institut de Chimie Moléculaire et des Matériaux d'Orsay, 91405, Orsay, France. .,Laboratoire de Chimie Moléculaire (LCM), CNRS UMR 9168, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91128 Palaiseau cedex, France
| |
Collapse
|
19
|
Abstract
Biocatalysis has an enormous impact on chemical synthesis. The waves in which biocatalysis has developed, and in doing so changed our perception of what organic chemistry is, were reviewed 20 and 10 years ago. Here we review the consequences of these waves of development. Nowadays, hydrolases are widely used on an industrial scale for the benign synthesis of commodity and bulk chemicals and are fully developed. In addition, further enzyme classes are gaining ever increasing interest. Particularly, enzymes catalysing selective C-C-bond formation reactions and enzymes catalysing selective oxidation and reduction reactions are solving long-standing synthetic challenges in organic chemistry. Combined efforts from molecular biology, systems biology, organic chemistry and chemical engineering will establish a whole new toolbox for chemistry. Recent developments are critically reviewed.
Collapse
Affiliation(s)
- Ulf Hanefeld
- Biocatalysis, Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, The Netherlands.
| | - Frank Hollmann
- Biocatalysis, Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, The Netherlands.
| | - Caroline E Paul
- Biocatalysis, Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, The Netherlands.
| |
Collapse
|
20
|
Pal S, Plapp BV. The Thr45Gly substitution in yeast alcohol dehydrogenase substantially decreases catalysis, alters pH dependencies, and disrupts the proton relay system. Chem Biol Interact 2021; 349:109650. [PMID: 34529977 PMCID: PMC8530938 DOI: 10.1016/j.cbi.2021.109650] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 08/19/2021] [Accepted: 09/09/2021] [Indexed: 10/20/2022]
Abstract
X-Ray crystallography shows that the hydroxyl group of Thr-45 in the fermentative alcohol dehydrogenase (ADH1) from Saccharomyces cerevisiae is hydrogen-bonded to the hydroxyl group of the alcohol bound to the catalytic zinc and is part of a proton relay system linked to His-48. The contribution of Thr-45 to catalysis was studied with steady state kinetics of the enzyme with the T45G substitution. Affinities for coenzymes decrease by only 2-4-fold, but the turnover numbers (V/Et) and catalytic efficiencies (V/KmEt) decrease 480-fold and 2900-fold for the oxidation of ethanol and 450-fold and 8400-fold for acetaldehyde reduction, respectively, relative to wild-type enzyme. Binding of NADH appears to require protonation of a group with a pK value of ∼7.4 in wild-type ADH1, but the pK value for T45G ADH1 appears to be less than 5. For wild-type enzyme, the pH dependencies for ethanol oxidation (V1/Et and V1/KbEt) are maximal above pK values of 7.0-7.7 and are attributed to the ionization of the alcohol or water bound to the catalytic zinc facilitated by His-48 in the enzyme-NAD+ complexes. For T45G ADH1, these pK values are shifted to 6.3. The reduction of acetaldehyde (V2/Et and V2/KpEt) modestly increases as the pH increases for wild-type and T45G enzymes. The removal of the hydroxyethyl group of Thr-45 disrupts the connection of the oxygen of ligands bound to the catalytic zinc with the proton relay system and formation of productive catalytic states. The conformational change of the enzyme and the exchange of ligands on the catalytic zinc can also be affected. Assignments of groups responsible for the pK values are discussed in the context of studies on other forms of horse liver and yeast ADHs. The substitutions with Ala-45 and Cys-45 in yeast ADH1 and the homologous substitutions with Ala-48 in horse and human liver ADHs also significantly decrease catalytic efficiency. Threonine or serine residues at this position in alcohol dehydrogenases are highly conserved and contribute substantially to catalysis.
Collapse
Affiliation(s)
- Suresh Pal
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52246, USA
| | - Bryce V Plapp
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52246, USA.
| |
Collapse
|
21
|
Brunetti E, Marcelis L, Zhurkin FE, Luhmer M, Jabin I, Reinaud O, Bartik K. A Water Molecule Triggers Guest Exchange at a Mono-Zinc Centre Confined in a Biomimetic Calixarene Pocket: a Model for Understanding Ligand Stability in Zn Proteins. Chemistry 2021; 27:13730-13738. [PMID: 34288166 DOI: 10.1002/chem.202102184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Indexed: 11/12/2022]
Abstract
In this study, the ligand exchange mechanism at a biomimetic ZnII centre, embedded in a pocket mimicking the possible constrains induced by a proteic structure, is explored. The residence time of different guest ligands (dimethylformamide, acetonitrile and ethanol) inside the cavity of a calix[6]arene-based tris(imidazole) tetrahedral zinc complex was probed using 1D EXchange SpectroscopY NMR experiments. A strong dependence of residence time on water content was observed with no exchange occurring under anhydrous conditions, even in the presence of a large excess of guest ligand. These results advocate for an associative exchange mechanism involving the transient exo-coordination of a water molecule, giving rise to 5-coordinate ZnII intermediates, and inversion of the pyramid at the ZnII centre. Theoretical modelling by DFT confirmed that the associative mechanism is at stake. These results are particularly relevant in the context of the understanding of kinetic stability/lability in Zn proteins and highlight the key role that a single water molecule can play in catalysing ligand exchange and controlling the lability of ZnII in proteins.
Collapse
Affiliation(s)
- Emilio Brunetti
- Engineering of Molecular Nanosystems, Université libre de Bruxelles, Avenue F. D. Roosevelt 50, CP165/64, 1050, Brussels, Belgium.,Laboratory of Organic Chemistry, Université libre de Bruxelles, Avenue F. D. Roosevelt 50, CP165/64, 1050, Brussels, Belgium
| | - Lionel Marcelis
- Engineering of Molecular Nanosystems, Université libre de Bruxelles, Avenue F. D. Roosevelt 50, CP165/64, 1050, Brussels, Belgium
| | - Fedor E Zhurkin
- Laboratory of Pharmacological and Toxicological Chemistry and Biochemistry, Université Paris Descartes, 45, rue des Saints-Pères, 75006, Paris, France
| | - Michel Luhmer
- High-Resolution Nuclear Magnetic Resonance laboratory, Université libre de Bruxelles, Avenue F. D. Roosevelt 50, CP165/64, 1050, Brussels, Belgium
| | - Ivan Jabin
- Laboratory of Organic Chemistry, Université libre de Bruxelles, Avenue F. D. Roosevelt 50, CP165/64, 1050, Brussels, Belgium
| | - Olivia Reinaud
- Laboratory of Pharmacological and Toxicological Chemistry and Biochemistry, Université Paris Descartes, 45, rue des Saints-Pères, 75006, Paris, France
| | - Kristin Bartik
- Engineering of Molecular Nanosystems, Université libre de Bruxelles, Avenue F. D. Roosevelt 50, CP165/64, 1050, Brussels, Belgium
| |
Collapse
|
22
|
Gorbunova IA, Sasin ME, Golyshev DP, Semenov AA, Smolin AG, Beltukov YM, Vasyutinskii OS. Two-Photon Excited Fluorescence Dynamics in Enzyme-Bound NADH: the Heterogeneity of Fluorescence Decay Times and Anisotropic Relaxation. J Phys Chem B 2021; 125:9692-9707. [PMID: 34410128 DOI: 10.1021/acs.jpcb.1c04226] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The dynamics of polarized fluorescence in NADH in alcohol dehydrogenase (ADH) in buffer solution has been studied using the TCSPC spectroscopy. A global fit procedure was used for determination of the fluorescence parameters from experiment. The interpretation of the results obtained was supported by ab initio calculations of the NADH structure. A theoretical model was developed describing the polarized fluorescence decay in ADH-NADH complexes that considered several interaction scenarios. A comparative analysis of the polarization-insensitive fluorescence decay using multiexponential fitting models has been carried out. As shown, the origin of a significant enhancement of the decay time in the ADH-NADH complex can be attributed to the decrease of nonradiative relaxation rates in the nicotinamide ring in the conditions of the apolar binding site environment. The existence of a single decay time in the ADH-NADH complex in comparison with two decay times observed in free NADH was attributed to a single NADH unfolded conformation in the ADH binding site. Comparison of the experimental data with the theoretical model suggested the existence of an anisotropic relaxation time of about 1 ns that is related with the rotation of fluorescence transition dipole moment due to the rearrangement of the excited state NADH nuclear configuration.
Collapse
Affiliation(s)
| | - Maxim E Sasin
- Ioffe Institute, 26 Polytekhnicheskaya, St. Petersburg, 194021, Russia
| | - Dmitrii P Golyshev
- Ioffe Institute, 26 Polytekhnicheskaya, St. Petersburg, 194021, Russia.,Peter the Great St.Petersburg Polytechnic University, 29 Polytechnicheskaya, St. Petersburg, 195251, Russia
| | | | - Andrey G Smolin
- Ioffe Institute, 26 Polytekhnicheskaya, St. Petersburg, 194021, Russia
| | | | | |
Collapse
|
23
|
Llull R, Montalbán G, Vidal I, Gomila RM, Bauzá A, Frontera A. Theoretical study of spodium bonding in the active site of three Zn-proteins and several model systems. Phys Chem Chem Phys 2021; 23:16888-16896. [PMID: 34328165 DOI: 10.1039/d1cp02150h] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In this manuscript, three examples retrieved from the PDB are selected to demonstrate the existence and relevance of spodium bonding (SpB) in biological systems. SpB is defined as an attractive noncovalent interaction between elements of group 12 of the periodic table acting as a Lewis acid and any atom or group of atoms acting as an electron donor. The utilization of this term (SpB) is convenient to differentiate classical coordination bonds from noncovalent interactions. In the latter, the distance between the electron rich and the spodium atoms is longer than the sum of the covalent radii but shorter than the sum of the van der Waals radii. In most Zn-dependent metalloenzymes, the spodium atom is bonded to three imidazole moieties belonging to the side chains of histidine amino-acids. Herein, in addition to the investigation of the SpB in the active site of three exemplifying enzymes, theoretical models where the Zn(ii) atom is bonded either to three imidazole or triazole ligands are used in order to investigate the strength of the SpB and its competition with hydrogen bonding. A series of Lewis bases and anions have been used as SpB acceptors combined with six SpB donors (receptors) of general formula [ZnY3X]+ (Y = imidazole and triazole and X = Cl, N3 and SCH3). In addition to the investigation of the energetic and geometric features of the complexes, the SpB interactions have been further characterized using the natural bond orbital (NBO) method, quantum theory of "atoms-in-molecules" and the noncovalent interaction plot (NCI plot).
Collapse
Affiliation(s)
- Rosa Llull
- Departament de Química, Universitat de les Illes Balears, Crta. de Valldemossa km 7.5, 07122 Palma de Mallorca (Baleares), Spain.
| | | | | | | | | | | |
Collapse
|
24
|
Marrone A, Fish RH. DFT Mechanism Studies: Biomimetic 1,4-NADH Chemoselective, Co-factor Regeneration with [Cp*Rh(bpy)H]+, in Tandem with the Biocatalysis Pathways of a Core Model of the (HLADH)-Zn(II) Mediated Enzyme, in the Enantioselective Reduction of Achiral Ketones to Chiral S-Alcohols. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.121810] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
25
|
Plapp BV, Subramanian R. Alternative binding modes in abortive NADH-alcohol complexes of horse liver alcohol dehydrogenase. Arch Biochem Biophys 2021; 701:108825. [PMID: 33675814 PMCID: PMC7980771 DOI: 10.1016/j.abb.2021.108825] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 10/22/2022]
Abstract
Enzymes typically have high specificity for their substrates, but the structures of substrates and products differ, and multiple modes of binding are observed. In this study, high resolution X-ray crystallography of complexes with NADH and alcohols show alternative modes of binding in the active site. Enzyme crystallized with the good substrates NAD+ and 4-methylbenzyl alcohol was found to be an abortive complex of NADH with 4-methylbenzyl alcohol rotated to a "non-productive" mode as compared to the structures that resemble reactive Michaelis complexes with NAD+ and 2,2,2-trifluoroethanol or 2,3,4,5,6-pentafluorobenzyl alcohol. The NADH is formed by reduction of the NAD+ with the alcohol during the crystallization. The same structure was also formed by directly crystallizing the enzyme with NADH and 4-methylbenzyl alcohol. Crystals prepared with NAD+ and 4-bromobenzyl alcohol also form the abortive complex with NADH. Surprisingly, crystals prepared with NAD+ and the strong inhibitor 1H,1H-heptafluorobutanol also had NADH, and the alcohol was bound in two different conformations that illustrate binding flexibility. Oxidation of 2-methyl-2,4-pentanediol during the crystallization apparently led to reduction of the NAD+. Kinetic studies show that high concentrations of alcohols can bind to the enzyme-NADH complex and activate or inhibit the enzyme. Together with previous studies on complexes with NADH and formamide analogues of the carbonyl substrates, models for the Michaelis complexes with NAD+-alcohol and NADH-aldehyde are proposed.
Collapse
Affiliation(s)
- Bryce V Plapp
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52242, USA.
| | | |
Collapse
|
26
|
Guntupalli SR, Li Z, Chang L, Plapp BV, Subramanian R. Cryo-Electron Microscopy Structures of Yeast Alcohol Dehydrogenase. Biochemistry 2021; 60:663-677. [PMID: 33620215 DOI: 10.1021/acs.biochem.0c00921] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Structures of yeast alcohol dehydrogenase determined by X-ray crystallography show that the subunits have two different conformational states in each of the two dimers that form the tetramer. Apoenzyme and holoenzyme complexes relevant to the catalytic mechanism were described, but the asymmetry led to questions about the cooperativity of the subunits in catalysis. This study used cryo-electron microscopy (cryo-EM) to provide structures for the apoenzyme, two different binary complexes with NADH, and a ternary complex with NAD+ and 2,2,2-trifluoroethanol. All four subunits in each of these complexes are identical, as the tetramers have D2 symmetry, suggesting that there is no preexisting asymmetry and that the subunits can be independently active. The apoenzyme and one enzyme-NADH complex have "open" conformations and the inverted coordination of the catalytic zinc with Cys-43, His-66, Glu-67, and Cys-153, whereas another enzyme-NADH complex and the ternary complex have closed conformations with the classical coordination of the zinc with Cys-43, His-66, Cys-153, and a water or the oxygen of trifluoroethanol. The conformational change involves interactions of Arg-340 with the pyrophosphate group of the coenzyme and Glu-67. The cryo-EM and X-ray crystallography studies provide structures relevant for the catalytic mechanism.
Collapse
Affiliation(s)
- Sai Rohit Guntupalli
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India.,Manipal University, Manipal, India.,Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Zhuang Li
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Leifu Chang
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Bryce V Plapp
- Department of Biochemistry, Bowen Science Building, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Ramaswamy Subramanian
- Department of Biological Sciences and Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| |
Collapse
|
27
|
Sandholu AS, Mujawar SP, Ramakrishnan K, Thulasiram HV, Kulkarni K. Structural studies on 10-hydroxygeraniol dehydrogenase: A novel linear substrate-specific dehydrogenase from Catharanthus roseus. Proteins 2020; 88:1197-1206. [PMID: 32181958 DOI: 10.1002/prot.25891] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 02/26/2020] [Accepted: 03/07/2020] [Indexed: 11/07/2022]
Abstract
Conversion of 10-hydroxygeraniol to 10-oxogeranial is a crucial step in iridoid biosynthesis. This reaction is catalyzed by a zinc-dependent alcohol dehydrogenase, 10-hydroxygeraniol dehydrogenase, belonging to the family of medium-chain dehydrogenase/reductase (MDR). Here, we report the crystal structures of a novel 10-hydroxygeraniol dehydrogenase from Catharanthus roseus in its apo and nicotinamide adenine dinucleotide phosphate (NADP+ ) bound forms. Structural analysis and docking studies reveal how subtle conformational differences of loops L1, L2, L3, and helix α9' at the orifice of the catalytic site confer differential activity of the enzyme toward various substrates, by modulating the binding pocket shape and volume. The present study, first of its kind, provides insights into the structural basis of substrate specificity of MDRs specific to linear substrates. Furthermore, comparison of apo and NADP+ bound structures suggests that the enzyme adopts open and closed states to facilitate cofactor binding.
Collapse
Affiliation(s)
- Anand S Sandholu
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, Maharashtra, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory, Pune, Maharashtra, India
| | - Sharmila P Mujawar
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, Maharashtra, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory, Pune, Maharashtra, India
| | - Krithika Ramakrishnan
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory, Pune, Maharashtra, India
- Division of Organic Chemistry, CSIR-National Chemical Laboratory, Pune, Maharashtra, India
| | - Hirekodathakallu V Thulasiram
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory, Pune, Maharashtra, India
- Division of Organic Chemistry, CSIR-National Chemical Laboratory, Pune, Maharashtra, India
| | - Kiran Kulkarni
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, Maharashtra, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory, Pune, Maharashtra, India
| |
Collapse
|
28
|
Kim K, Plapp BV. Substitutions of Amino Acid Residues in the Substrate Binding Site of Horse Liver Alcohol Dehydrogenase Have Small Effects on the Structures but Significantly Affect Catalysis of Hydrogen Transfer. Biochemistry 2020; 59:862-879. [PMID: 31994873 DOI: 10.1021/acs.biochem.9b01074] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous studies showed that the L57F and F93W alcohol dehydrogenases catalyze the oxidation of benzyl alcohol with some quantum mechanical hydrogen tunneling, whereas the V203A enzyme has diminished tunneling. Here, steady-state kinetics for the L57F and F93W enzymes were studied, and microscopic rate constants for the ordered bi-bi mechanism were estimated from simulations of transient kinetics for the S48T, F93A, S48T/F93A, F93W, and L57F enzymes. Catalytic efficiencies for benzyl alcohol oxidation (V1/EtKb) vary over a range of ∼100-fold for the less active enzymes up to the L57F enzyme and are mostly associated with the binding of alcohol rather than the rate constants for hydride transfer. In contrast, catalytic efficiencies for benzaldehyde reduction (V2/EtKp) are ∼500-fold higher for the L57F enzyme than for the less active enzymes and are mostly associated with the rate constants for hydride transfer. Atomic-resolution structures (1.1 Å) for the F93W and L57F enzymes complexed with NAD+ and 2,3,4,5,6-pentafluorobenzyl alcohol or 2,2,2-trifluoroethanol are almost identical to previous structures for the wild-type, S48T, and V203A enzymes. Least-squares refinement with SHELXL shows that the nicotinamide ring is slightly strained in all complexes and that the apparent donor-acceptor distances from C4N of NAD to C7 of pentafluorobenzyl alcohol range from 3.28 to 3.49 Å (±0.02 Å) and are not correlated with the rate constants for hydride transfer or hydrogen tunneling. How the substitutions affect the dynamics of reorganization during hydrogen transfer and the extent of tunneling remain to be determined.
Collapse
Affiliation(s)
- Keehyuk Kim
- Department of Biochemistry , The University of Iowa , Iowa City , Iowa 52242 , United States
| | - Bryce V Plapp
- Department of Biochemistry , The University of Iowa , Iowa City , Iowa 52242 , United States
| |
Collapse
|
29
|
Pohanka M. Antidotes Against Methanol Poisoning: A Review. Mini Rev Med Chem 2019; 19:1126-1133. [PMID: 30864518 DOI: 10.2174/1389557519666190312150407] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/20/2019] [Accepted: 03/06/2019] [Indexed: 12/12/2022]
Abstract
Methanol is the simplest alcohol. Compared to ethanol that is fully detoxified by metabolism. Methanol gets activated in toxic products by the enzymes, alcohol dehydrogenase and aldehyde dehydrogenase. Paradoxically, the same enzymes convert ethanol to harmless acetic acid. This review is focused on a discussion and overview of the literature devoted to methanol toxicology and antidotal therapy. Regarding the antidotal therapy, three main approaches are presented in the text: 1) ethanol as a competitive inhibitor in alcohol dehydrogenase; 2) use of drugs like fomepizole inhibiting alcohol dehydrogenase; 3) tetrahydrofolic acid and its analogues reacting with the formate as a final product of methanol metabolism. All the types of antidotal therapies are described and how they protect from toxic sequelae of methanol is explained.
Collapse
Affiliation(s)
- Miroslav Pohanka
- Faculty of Military Health Sciences, University of Defense, Trebesska 1575, Hradec Kralove CZ-50001, Czech Republic
| |
Collapse
|
30
|
Fontana LA, Siqueira JD, Ceolin J, Iglesias BA, Piquini PC, Neves A, Back DF. Peroxidase activity of new mixed‐valence cobalt complexes with ligands derived from pyridoxal. Appl Organomet Chem 2019. [DOI: 10.1002/aoc.4903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Liniquer André Fontana
- Laboratório de Materiais Inorgânicos – Departamento de QuímicaCCNE, UFSM 97105‐900 Santa Maria RS Brazil
| | - Josiéli Demetrio Siqueira
- Laboratório de Materiais Inorgânicos – Departamento de QuímicaCCNE, UFSM 97105‐900 Santa Maria RS Brazil
| | - Joice Ceolin
- Laboratório de Materiais Inorgânicos – Departamento de QuímicaCCNE, UFSM 97105‐900 Santa Maria RS Brazil
| | | | | | - Ademir Neves
- Departamento de QuímicaUniversidade Federal de Santa Catarina, UFSC 88040‐970 Florianópolis SC Brazil
| | - Davi Fernando Back
- Laboratório de Materiais Inorgânicos – Departamento de QuímicaCCNE, UFSM 97105‐900 Santa Maria RS Brazil
| |
Collapse
|
31
|
Kim K, Plapp BV. Substitution of cysteine-153 ligated to the catalytic zinc in yeast alcohol dehydrogenase with aspartic acid and analysis of mechanisms of related medium chain dehydrogenases. Chem Biol Interact 2019; 302:172-182. [PMID: 30721696 DOI: 10.1016/j.cbi.2019.01.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 01/14/2019] [Accepted: 01/31/2019] [Indexed: 11/28/2022]
Abstract
The catalytic zincs in complexes of horse liver and yeast alcohol dehydrogenases (ADH) with NAD+ and the substrate analogue, 2,2,2-trifluoroethanol, are ligated to two cysteine residues and one histidine residue from the protein and the oxygen from the alcohol. The zinc facilitates deprotonation of the alcohol and is essential for catalysis. In the yeast apoenzyme, the zinc is coordinated to a nearby glutamic acid, which is displaced by the alcohol in the complex with NAD+. Some homologous medium chain dehydrogenases have a cysteine replaced by aspartic or glutamic acid residues. How an aspartic acid would affect catalysis was studied by replacing Cys-153 in Saccharomyces cerevisiae ADH1 by using site-directed mutagenesis. The C153D enzyme was about as stable as the wild-type enzyme, if EDTA was not included in the buffers. The substitution increased affinity for NAD+ by 3-fold, but did not affect NADH binding. At pH 7.3, the turnover number for ethanol oxidation (V1/Et) decreased by 7-fold and catalytic efficiency decreased 18-fold (V1/EtKb), but turnover for acetaldehyde reduction (V2/Et) was the same as for wild-type enzyme and catalytic efficiency decreased 8-fold (V2/EtKp). Deuterium isotope effects of 3.0 on V1/Et and 3.8 on V1/EtKb for ethanol oxidation suggest that hydride transfer is more rate-limiting for turnover for the C153D enzyme than by wild-type enzyme. The patterns of pH dependence for V1/EtKb for ethanol oxidation were similar for both enzymes in the pH range from 7 to 9. The C153D substitution decreased binding of trifluoroethanol by 5-fold and of pyrazole by 65-fold. Substrate specificities for C153D and wild-type ADHs for primary alcohols have similar patterns. Efficiency for secondary alcohols decreased only about 4-fold, and efficiencies for 1,2-propanediol and acetone were about the same as for wild-type enzyme. The C153D substitution modestly affects catalysis by altering ligand exchange on the zinc or local structure. Structures and mechanisms for acid-base catalysis in related medium chain dehydrogenases with substitutions of the homologous cysteine are reviewed and analyzed.
Collapse
Affiliation(s)
- Keehyuk Kim
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52242, USA.
| | - Bryce V Plapp
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52242, USA.
| |
Collapse
|
32
|
Substitutions of a buried glutamate residue hinder the conformational change in horse liver alcohol dehydrogenase and yield a surprising complex with endogenous 3'-Dephosphocoenzyme A. Arch Biochem Biophys 2018; 653:97-106. [PMID: 30018019 DOI: 10.1016/j.abb.2018.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 06/30/2018] [Accepted: 07/05/2018] [Indexed: 11/22/2022]
Abstract
Glu-267 is highly conserved in alcohol dehydrogenases and buried as a negatively-charged residue in a loop of the NAD coenzyme binding domain. Glu-267 might have a structural role and contribute to a rate-promoting vibration that facilitates catalysis. Substitutions of Glu-267 with histidine or asparagine residues increase the dissociation constants for the coenzymes (NAD+ by ∼40-fold, NADH by ∼200-fold) and significantly decrease catalytic efficiencies by 16-1200-fold various substrates and substituted enzymes. The turnover numbers modestly change with the substitutions, but hydride transfer is at least partially rate-limiting for turnover for alcohol oxidation. X-ray structures of the E267H and E267 N enzymes are similar to the apoenzyme (open) conformation of the wild-type enzyme, and the substitutions are accommodated by local changes in the structure. Surprisingly, the E267H and E267 N enzymes have endogenous (from the expression in E. coli) 3'-dephosphocoenzyme A bound in the active site with the ADP moiety in the NAD binding site and the pantethiene sulfhydryl bound to the catalytic zinc. The kinetics and crystallography show that the substitutions of Glu-267 hinder the conformational change, which occurs when wild-type enzyme binds coenzymes, and affect productive binding of substrates.
Collapse
|