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Roth S, Niese R, Müller M, Hall M. Redox Out of the Box: Catalytic Versatility Across NAD(P)H-Dependent Oxidoreductases. Angew Chem Int Ed Engl 2024; 63:e202314740. [PMID: 37924279 DOI: 10.1002/anie.202314740] [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: 10/01/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/06/2023]
Abstract
The asymmetric reduction of double bonds using NAD(P)H-dependent oxidoreductases has proven to be an efficient tool for the synthesis of important chiral molecules in research and on industrial scale. These enzymes are commercially available in screening kits for the reduction of C=O (ketones), C=C (activated alkenes), or C=N bonds (imines). Recent reports, however, indicate that the ability to accommodate multiple reductase activities on distinct C=X bonds occurs in different enzyme classes, either natively or after mutagenesis. This challenges the common perception of highly selective oxidoreductases for one type of electrophilic substrate. Consideration of this underexplored potential in enzyme screenings and protein engineering campaigns may contribute to the identification of complementary biocatalytic processes for the synthesis of chiral compounds. This review will contribute to a global understanding of the promiscuous behavior of NAD(P)H-dependent oxidoreductases on C=X bond reduction and inspire future discoveries with respect to unconventional biocatalytic routes in asymmetric synthesis.
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Affiliation(s)
- Sebastian Roth
- Institute of Chemistry, University of Graz, Heinrichstrasse 28, 8010, Graz, Austria
| | - Richard Niese
- Institute of Pharmaceutical Sciences, University of Freiburg, Albertstrasse 25, 79104, Freiburg, Germany
| | - Michael Müller
- Institute of Pharmaceutical Sciences, University of Freiburg, Albertstrasse 25, 79104, Freiburg, Germany
| | - Mélanie Hall
- Institute of Chemistry, University of Graz, Heinrichstrasse 28, 8010, Graz, Austria
- BioHealth, Field of Excellence, University of Graz, 8010, Graz, Austria
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2
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Plapp BV. Solvent isotope and mutagenesis studies on the proton relay system in yeast alcohol dehydrogenase 1. Chem Biol Interact 2024; 388:110853. [PMID: 38151107 PMCID: PMC10843573 DOI: 10.1016/j.cbi.2023.110853] [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: 10/13/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 12/29/2023]
Abstract
Alcohol dehydrogenase catalyzes the reversible transfer of a hydride directly from an alcohol to the nicotinamide ring of NAD+ to form an aldehyde and NADH, and the proton from the alcohol probably is transferred through a hydrogen-bonded system to the imidazole of His-48. Studies of the pH dependencies, and solvent and substrate isotope effects on the wild-type and the enzyme with His-48 substituted with Gln-48 were used to demonstrate a role for the proton relay system. The H48Q substitution increases affinities for NAD+ and NADH by ∼2-fold, suggesting that the overall protein structure is maintained. In contrast, catalytic efficiencies (V/Km) on ethanol and acetaldehyde and affinity for 2,2,2-trifluoroethanol are decreased by about 10-fold. The pH dependencies for catalytic efficiencies on ethanol and acetaldehyde (log V/Km versus pH), show pK values of about 7.5 for wild-type enzyme, but ethanol oxidation by H48Q ADH is essentially linear over the pH range from 5.5 to 9.2 with a slope of 0.47. Steady-state kinetics and substrate isotope effects suggest that the kinetic mechanism of H48Q ADH has become partly random for oxidation of ethanol. Both wild-type and H48Q ADHs have pH-independent isotope effects for oxidation (V1/Kb) of 1-butanol/1-butanol-d9 of 4, suggesting that hydride transfer is a major rate-limiting step. The pH dependence for butanol oxidation by wild type ADH shows a wavy profile over the pH range from pH 6 to 10, with a ∼2.3-fold larger V1/Kb in D2O than in H2O, an "inverse" isotope effect. The substrate isotope effect of 4 is not altered by the solvent isotope effect, suggesting concerted proton/hydride transfer. The solvent isotope effect can be explained by a ground state with a water bound to the catalytic zinc in the enzyme-NAD+ complex, and a transition state that resembles a complex with NADH and aldehyde. In contrast, the H48Q enzyme has a diminished inverse solvent isotope effect of ∼1.3 and an essentially linear pH dependence with a slope of log V1/Kb against pH of 0.49 for oxidation of 1-butanol, which together are consistent with a transition state where hydroxide ion directly accepts a proton from the 2'-hydroxyl group of the nicotinamide ribose in the proton relay system in the enzyme-NAD+-alcohol complex. The results support a catalytic role for His-48 in the proton relay system.
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Affiliation(s)
- Bryce V Plapp
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA, 52242, USA.
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3
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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.
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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
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4
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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.
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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
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5
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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.
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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.
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6
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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.
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Affiliation(s)
- Bryce V Plapp
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52242, USA.
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7
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Musa MM, Vieille C, Phillips RS. Secondary Alcohol Dehydrogenases from Thermoanaerobacter pseudoethanolicus and Thermoanaerobacter brockii as Robust Catalysts. Chembiochem 2021; 22:1884-1893. [PMID: 33594812 DOI: 10.1002/cbic.202100043] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/15/2021] [Indexed: 11/06/2022]
Abstract
Alcohol dehydrogenases (ADHs) are an important type of enzyme that have significant applications as biocatalysts. Secondary ADHs from Thermoanaerobacter pseudoethanolicus (TeSADH) and Thermoanaerobacter brockii (TbSADH) are well-known as robust catalysts. However, like most other ADHs, these enzymes suffer from their high substrate specificities (i. e., limited substrate scope), which to some extent restricts their use as biocatalysts. This minireview discusses recent efforts to expand the substrate scope and tune the enantioselectivity of TeSADH and TbSADH by using site-directed mutagenesis and directed evolution. Various examples of asymmetric synthesis of optically active alcohols using both enzymes are highlighted. Moreover, the unique thermal stability and organic solvent tolerance of these enzymes is illustrated by their concurrent inclusion with other interesting reactions to synthesize optically active alcohols and amines. For instance, TeSADH has been used in quantitative non-stereoselective oxidation of alcohols to deracemize alcohols via cyclic deracemization and in the racemization of enantiopure alcohols to accomplish a bienzymatic dynamic kinetic resolution.
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Affiliation(s)
- Musa M Musa
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia
| | - Claire Vieille
- Department of Microbiology and Molecular Genetics and, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Robert S Phillips
- Department of Chemistry and, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
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8
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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.
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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
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9
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Fine-Tuning of Sequence Specificity by Near Attack Conformations in Enzyme-Catalyzed Peptide Hydrolysis. Catalysts 2020. [DOI: 10.3390/catal10060684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The catalytic role of near attack conformations (NACs), molecular states that lie on the pathway between the ground state (GS) and transition state (TS) of a chemical reaction, is not understood completely. Using a computational approach that combines Bürgi–Dunitz theory with all-atom molecular dynamics simulations, the role of NACs in catalyzing the first stages of HIV-1 protease peptide hydrolysis was previously investigated using a substrate that represents the recognized SP1-NC cleavage site of the HIV-1 Gag polyprotein. NACs were found to confer no catalytic effect over the uncatalyzed reaction there ( Δ Δ G N ‡ ∼ 0 kcal/mol). Here, using the same approach, the role of NACs across multiple substrates that each represent a further recognized cleavage site is investigated. Overall rate enhancement varies by | Δ Δ G ‡ | ∼ 12–15 kcal/mol across this set, and although NACs contribute a small and approximately constant barrier to the uncatalyzed reaction (< Δ G N ‡ u > = 4.3 ± 0.3 kcal/mol), they are found to contribute little significant catalytic effect ( | Δ Δ G N ‡ | ∼ 0–2 kcal/mol). Furthermore, no correlation is exhibited between NAC contributions and the overall energy barrier ( R 2 = 0.01). However, these small differences in catalyzed NAC contributions enable rates to match those required for the kinetic order of processing. Therefore, NACs may offer an alternative and subtle mode compared to non-NAC contributions for fine-tuning reaction rates during complex evolutionary sequence selection processes—in this case across cleavable polyproteins whose constituents exhibit multiple functions during the virus life-cycle.
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10
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Paul TK, Taraphder S. Coordination Dynamics of Zinc Triggers the Rate Determining Proton Transfer in Human Carbonic Anhydrase II. Chemphyschem 2020; 21:1455-1473. [DOI: 10.1002/cphc.202000177] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/17/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Tanmoy Kumar Paul
- Department of Chemistry Indian Institute of Technology Kharagpur 721302 India
| | - Srabani Taraphder
- Department of Chemistry Indian Institute of Technology Kharagpur 721302 India
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11
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Sheng X, Kazemi M, Planas F, Himo F. Modeling Enzymatic Enantioselectivity using Quantum Chemical Methodology. ACS Catal 2020. [DOI: 10.1021/acscatal.0c00983] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Xiang Sheng
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-106 91, Sweden
| | - Masoud Kazemi
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-106 91, Sweden
| | - Ferran Planas
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-106 91, Sweden
| | - Fahmi Himo
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-106 91, Sweden
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12
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Mu X, Xu D. QM/MM investigation of substrate binding of subclass B3 metallo-β-lactamase SMB-1 from Serratia marcescents: insights into catalytic mechanism. J Mol Model 2020; 26:71. [PMID: 32146530 DOI: 10.1007/s00894-020-4330-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 02/23/2020] [Indexed: 11/25/2022]
Abstract
Metallo-β-lactamases (MβLs) can hydrolyze and deactivate lactam-containing antibiotics, which are the major mechanism to cause drug resistance in the treatment of bacterial infections. This has become a global concern due to the lack of clinically approved inhibitors so far. SMB-1 from Serratia marcescents is a novel B3 subclass MβL, which could inactivate nearly all β-lactam-containing antibiotics, e.g., cephalosporins and carbapenems. It represents a new round of worrisome bacterial resistance. In this work, the Michaelis model of SMB-1 in complex with ampicillin was simulated using combined quantum mechanical and molecular mechanical method. Similar with other dizinc MβLs, a Zn-bridged hydroxide ion was simulated as the nucleophile for the hydrolysis reaction assisted by D120. The protonation of D120 could lead to the loss of Oδ2-Zn2 coordination bond, whereas the C3 carboxylate group moves down to become a new ligand to Zn2. The initial β-lactam ring-opening reaction leads to a conserved nitrogen anionic intermediate, which forms a new ligation between the resulted nitrogen anion and Zn2. The corresponding reaction free energy barrier for the first step of lactam ring-opening reaction was calculated to be 19.2 kcal/mol. During the reaction, Q157 serves as the putative "oxyanion hole" rather than Zn1 in L1 enzyme, which was confirmed via the site-directed mutagenesis simulation of Q157A. Our theoretical studies showed some insights into the substrate binding and catalytic mechanism of the SMB-1 metallo-β-lactamase.
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Affiliation(s)
- Xia Mu
- College of Chemistry, MOE Key Laboratory of Green Chemistry and Technology, Sichuan University, Chengdu, 610064, Sichuan, People's Republic of China
| | - Dingguo Xu
- College of Chemistry, MOE Key Laboratory of Green Chemistry and Technology, Sichuan University, Chengdu, 610064, Sichuan, People's Republic of China. .,Research Center for Material Genome Engineering, Sichuan University, Chengdu, 610065, Sichuan, People's Republic of China.
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13
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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.
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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
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14
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Kohen A. Kinetic Isotope Effects as Probes for Hydrogen Tunneling, Coupled Motion and Dynamics Contributions to Enzyme Catalysis. PROGRESS IN REACTION KINETICS AND MECHANISM 2019. [DOI: 10.3184/007967403103165486] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Since the early days of enzymology attempts have been made to deconvolute the various contributions of physical phenomena to enzyme catalysis. Here we present experimental and theoretical studies that examine the possible role of hydrogen tunneling, coupled motion, and enzyme dynamics in catalysis. In this review, we first introduce basic concepts of enzyme catalysis from a physical chemistry point of view. Then, we present several recent developments in the application of experimental tools that can probe tunneling, coupled motion, dynamic effects and other possible physical phenomena that may contribute to catalysis. These tools include kinetic isotope effects (KIEs), their temperature dependency and H/D/T mutual relations (the Swain–Schaad relationship). Several theories and models that assist in understanding those phenomena are also described. The possibility that these models invoke a direct role for the enzyme's dynamics (environmental fluctuations and rearrangements) is discussed. Finally, the need to compare the enzymatic reaction to the uncatalyzed one while investigating contributions to catalysis is emphasised.
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Affiliation(s)
- Amnon Kohen
- Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA
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15
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Ketoacidosis - Where Do the Protons Come From? Trends Biochem Sci 2019; 44:484-489. [PMID: 30744927 DOI: 10.1016/j.tibs.2019.01.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/10/2019] [Accepted: 01/14/2019] [Indexed: 12/26/2022]
Abstract
In extreme conditions ketosis can progress to ketoacidosis, a dangerous and potentially life-threatening condition. Ketoacidosis is most common in new or poorly treated type 1 diabetes. The acidosis is usually attributed to the 'acidic' nature of the ketone bodies (acetoacetate, 3-hydroxybutyrate, and acetone). However, acetoacetate and 3-hydroxybutyrate are produced not as acids but as their conjugate bases, and acetone is neither an acid nor a base. This raises the question of why severe ketosis is accompanied by acidosis. Here, we analyze steps in ketogenesis and identify four potential sources: adipocyte lipolysis, hydrolysis of inorganic pyrophosphate generated during synthesis of fatty acyl-coenzyme A (CoA), the reaction catalyzed by an enzyme in the β-oxidation pathway (3-hydroxyacyl-CoA dehydrogenase), and increased synthesis of CoA.
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16
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Wei WJ, Qian HX, Wang WJ, Liao RZ. Computational Understanding of the Selectivities in Metalloenzymes. Front Chem 2018; 6:638. [PMID: 30622942 PMCID: PMC6308299 DOI: 10.3389/fchem.2018.00638] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/07/2018] [Indexed: 01/26/2023] Open
Abstract
Metalloenzymes catalyze many different types of biological reactions with high efficiency and remarkable selectivity. The quantum chemical cluster approach and the combined quantum mechanics/molecular mechanics methods have proven very successful in the elucidation of the reaction mechanism and rationalization of selectivities in enzymes. In this review, recent progress in the computational understanding of various selectivities including chemoselectivity, regioselectivity, and stereoselectivity, in metalloenzymes, is discussed.
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Affiliation(s)
| | | | | | - Rong-Zhen Liao
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, China
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17
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Paidimuddala B, Mohapatra SB, Gummadi SN, Manoj N. Crystal structure of yeast xylose reductase in complex with a novel NADP-DTT adduct provides insights into substrate recognition and catalysis. FEBS J 2018; 285:4445-4464. [PMID: 30269423 DOI: 10.1111/febs.14667] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/13/2018] [Accepted: 09/26/2018] [Indexed: 11/30/2022]
Abstract
Aldose reductases (ARs) belonging to the aldo-keto reductase (AKR) superfamily catalyze the conversion of carbonyl substrates into their respective alcohols. Here we report the crystal structures of the yeast Debaryomyces nepalensis xylose reductase (DnXR, AKR2B10) in the apo form and as a ternary complex with a novel NADP-DTT adduct. Xylose reductase, a key enzyme in the conversion of xylose to xylitol, has several industrial applications. The enzyme displayed the highest catalytic efficiency for l-threose (138 ± 7 mm-1 ·s-1 ) followed by d-erythrose (30 ± 3 mm-1 ·s-1 ). The crystal structure of the complex reveals a covalent linkage between the C4N atom of the nicotinamide ring of the cosubstrate and the S1 sulfur atom of DTT and provides the first structural evidence for a protein mediated NADP-low-molecular-mass thiol adduct. We hypothesize that the formation of the adduct is facilitated by an in-crystallo Michael addition of the DTT thiolate to the specific conformation of bound NADPH in the active site of DnXR. The interactions between DTT, a four-carbon sugar alcohol analog, and the enzyme are representative of a near-cognate product ternary complex and provide significant insights into the structural basis of aldose binding and specificity and the catalytic mechanism of ARs. DATABASE: Structural data are available in the PDB under the accession numbers 5ZCI and 5ZCM.
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Affiliation(s)
- Bhaskar Paidimuddala
- Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Samar B Mohapatra
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Sathyanarayana N Gummadi
- Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Narayanan Manoj
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
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18
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Xiong J, Zhang C, Xu D. Catalytic mechanism of type C sialidase from Streptococcus pneumoniae: from covalent intermediate to final product. J Mol Model 2018; 24:297. [PMID: 30259133 DOI: 10.1007/s00894-018-3822-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 09/04/2018] [Indexed: 12/24/2022]
Abstract
Streptococcus pneumoniae is a Gram-positive human pathogenic bacterium, which is the main cause of pneumonia and meningitis in children and the elderly. Three sialidases (or neuraminidases) encoded from Streptococcus pneumoniae could catalyze the cleavage of sialic acid linkages. This mechanism is directly connected with infection, apoptosis, and signaling, and usually considered to be one of the critical virulence factors. Type C neuraminidase (NanC) is unique because its primary product of Neu5Ac2en is considered to be an inhibitor to the other two sialidases. Experimentally, there are two different pathways for the formation mechanism of Neu5Ac2en catalyzed by NanC. In this work, a combined quantum mechanical and molecular mechanical approach was employed in all calculations. Starting from the covalent sialylated intermediate, we first examined the reaction to Neu5Ac2en and found the reaction prefers a direct proton abstraction mechanism rather than the water mediated proton abstraction mechanism. Free energy profiles can confirm that Neu5Ac2en is the major product of NanC. Functional roles of some important residues were also investigated, e.g., D315 acts as the proton acceptor during the formation of Neu5Ac2en, while the general base for the hydrolytic reaction to Neu5Ac. This study can facilitate the understanding of the catalytic mechanism of NanC and has the potential to aid in future inhibitor design studies.
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Affiliation(s)
- Jing Xiong
- MOE Key Laboratory of Green Chemistry & Technology, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, People's Republic of China
- School of Pharmacy, Chengdu Medical College, Chengdu, Sichuan, 610500, People's Republic of China
| | - Chunchun Zhang
- Analytical&Testing Center, Sichuan University, Chengdu, Sichuan, 610064, People's Republic of China.
| | - Dingguo Xu
- MOE Key Laboratory of Green Chemistry & Technology, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, People's Republic of China.
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19
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Church JR, Skodje RT. Double Hydrogen-Atom Exchange Reactions of HX (X = F, Cl, Br, I) with HO2. J Phys Chem A 2018; 122:5251-5260. [DOI: 10.1021/acs.jpca.8b01602] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jonathan R. Church
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Rex T. Skodje
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
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20
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Prakash P, Punekar NS, Bhaumik P. Structural basis for the catalytic mechanism and α-ketoglutarate cooperativity of glutamate dehydrogenase. J Biol Chem 2018. [PMID: 29540480 DOI: 10.1074/jbc.ra117.000149] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glutamate dehydrogenase (GDH) is a key enzyme connecting carbon and nitrogen metabolism in all living organisms. Despite extensive studies on GDHs from both prokaryotic and eukaryotic organisms in the last 40 years, the structural basis of the catalytic features of this enzyme remains incomplete. This study reports the structural basis of the GDH catalytic mechanism and allosteric behavior. We determined the first high-resolution crystal structures of glutamate dehydrogenase from the fungus Aspergillus niger (AnGDH), a unique NADP+-dependent allosteric enzyme that is forward-inhibited by the formation of mixed disulfide. We determined the structures of the active enzyme in its apo form and in binary/ternary complexes with bound substrate (α-ketoglutarate), inhibitor (isophthalate), coenzyme (NADPH), or two reaction intermediates (α-iminoglutarate and 2-amino-2-hydroxyglutarate). The structure of the forward-inhibited enzyme (fiAnGDH) was also determined. The hexameric AnGDH had three open subunits at one side and three partially closed protomers at the other, a configuration not previously reported. The AnGDH hexamers having subunits with different conformations indicated that its α-ketoglutarate-dependent homotropic cooperativity follows the Monod-Wyman-Changeux (MWC) model. Moreover, the position of the water attached to Asp-154 and Gly-153 defined the previously unresolved ammonium ion-binding pocket, and the binding site for the 2'-phosphate group of the coenzyme was also better defined by our structural data. Additional structural and mutagenesis experiments identified the residues essential for coenzyme recognition. This study reveals the structural features responsible for positioning α-ketoglutarate, NADPH, ammonium ion, and the reaction intermediates in the GDH active site.
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Affiliation(s)
- Prem Prakash
- From the Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
| | - Narayan S Punekar
- From the Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
| | - Prasenjit Bhaumik
- From the Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
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21
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Paul S, Paul TK, Taraphder S. Reaction Coordinate, Free Energy, and Rate of Intramolecular Proton Transfer in Human Carbonic Anhydrase II. J Phys Chem B 2018; 122:2851-2866. [DOI: 10.1021/acs.jpcb.7b10713] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sanjib Paul
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Tanmoy Kumar Paul
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Srabani Taraphder
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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22
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Shanmuganatham KK, Wallace RS, Ting-I Lee A, Plapp BV. Contribution of buried distal amino acid residues in horse liver alcohol dehydrogenase to structure and catalysis. Protein Sci 2018; 27:750-768. [PMID: 29271062 DOI: 10.1002/pro.3370] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/18/2017] [Accepted: 12/20/2017] [Indexed: 01/06/2023]
Abstract
The dynamics of enzyme catalysis range from the slow time scale (∼ms) for substrate binding and conformational changes to the fast time (∼ps) scale for reorganization of substrates in the chemical step. The contribution of global dynamics to catalysis by alcohol dehydrogenase was tested by substituting five different, conserved amino acid residues that are distal from the active site and located in the hinge region for the conformational change or in hydrophobic clusters. X-ray crystallography shows that the structures for the G173A, V197I, I220 (V, L, or F), V222I, and F322L enzymes complexed with NAD+ and an analogue of benzyl alcohol are almost identical, except for small perturbations at the sites of substitution. The enzymes have very similar kinetic constants for the oxidation of benzyl alcohol and reduction of benzaldehyde as compared to the wild-type enzyme, and the rates of conformational changes are not altered. Less conservative substitutions of these amino acid residues, such as G173(V, E, K, or R), V197(G, S, or T), I220(G, S, T, or N), and V222(G, S, or T) produced unstable or poorly expressed proteins, indicating that the residues are critical for global stability. The enzyme scaffold accommodates conservative substitutions of distal residues, and there is no evidence that fast, global dynamics significantly affect the rate constants for hydride transfers. In contrast, other studies show that proximal residues significantly participate in catalysis.
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Affiliation(s)
- Karthik K Shanmuganatham
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52242-1109.,Diagnostic Virology Laboratory, USDA, Ames, IA, 50010
| | - Rachel S Wallace
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52242-1109.,Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, 9054, New Zealand
| | - Ann Ting-I Lee
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52242-1109.,No 92, Jing Mao 1st Rd., Taichung, Taiwan, 406, Republic of China
| | - Bryce V Plapp
- Department of Biochemistry, The University of Iowa, Iowa City, IA, 52242-1109
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23
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An B, Zeng L, Jia M, Li Z, Lin Z, Song Y, Zhou Y, Cheng J, Wang C, Lin W. Molecular Iridium Complexes in Metal–Organic Frameworks Catalyze CO2 Hydrogenation via Concerted Proton and Hydride Transfer. J Am Chem Soc 2017; 139:17747-17750. [DOI: 10.1021/jacs.7b10922] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bing An
- Collaborative
Innovation Center of Chemistry for Energy Materials, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Lingzhen Zeng
- Collaborative
Innovation Center of Chemistry for Energy Materials, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Mei Jia
- Collaborative
Innovation Center of Chemistry for Energy Materials, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Zhe Li
- Collaborative
Innovation Center of Chemistry for Energy Materials, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Zekai Lin
- Department
of Chemistry, University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Yang Song
- Department
of Chemistry, University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Yang Zhou
- Collaborative
Innovation Center of Chemistry for Energy Materials, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Jun Cheng
- Collaborative
Innovation Center of Chemistry for Energy Materials, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Cheng Wang
- Collaborative
Innovation Center of Chemistry for Energy Materials, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Wenbin Lin
- Collaborative
Innovation Center of Chemistry for Energy Materials, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
- Department
of Chemistry, University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, United States
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24
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Ensari Y, Dhoke GV, Davari MD, Bocola M, Ruff AJ, Schwaneberg U. Inversion of cpADH5 Enantiopreference and Altered Chain Length Specificity for Methyl 3-Hydroxyalkanoates. Chemistry 2017; 23:12636-12645. [DOI: 10.1002/chem.201702581] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Yunus Ensari
- Lehrstuhl für Biotechnologie; RWTH Aachen University; Worringerweg 3 52074 Aachen Germany
- Faculty of Engineering and Architecture; Department of Bioengineering; Kafkas University; Kars Turkey
| | - Gaurao V. Dhoke
- Lehrstuhl für Biotechnologie; RWTH Aachen University; Worringerweg 3 52074 Aachen Germany
| | - Mehdi D. Davari
- Lehrstuhl für Biotechnologie; RWTH Aachen University; Worringerweg 3 52074 Aachen Germany
| | - Marco Bocola
- Lehrstuhl für Biotechnologie; RWTH Aachen University; Worringerweg 3 52074 Aachen Germany
| | - Anna Joëlle Ruff
- Lehrstuhl für Biotechnologie; RWTH Aachen University; Worringerweg 3 52074 Aachen Germany
| | - Ulrich Schwaneberg
- Lehrstuhl für Biotechnologie; RWTH Aachen University; Worringerweg 3 52074 Aachen Germany
- DWI-Leibniz Institut für Interaktive Materialien; Forckenbeckstraße 50 52056 Aachen Germany
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25
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Moa S, Himo F. Quantum chemical study of mechanism and stereoselectivity of secondary alcohol dehydrogenase. J Inorg Biochem 2017; 175:259-266. [PMID: 28803132 DOI: 10.1016/j.jinorgbio.2017.07.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/02/2017] [Accepted: 07/18/2017] [Indexed: 11/17/2022]
Abstract
Secondary alcohol dehydrogenase from Thermoanaerobacter brockii (TbSADH) is a Zn- and NADP-dependent enzyme that catalyses the reversible transformation of secondary alcohols into ketones. It is of potential biocatalytic interest as it can be used in the synthesis of chiral alcohols by asymmetric reduction of ketones. In this paper, density functional theory calculations are employed to elucidate the origins of the enantioselectivity of TbSADH using a large model of the active site and considering two different substrates, 2-butanol and 3-hexanol. For these two substrates the enzyme has experimentally been shown to have the opposite enantioselectivity. The energy profiles for the reactions are calculated and the stationary points along the reaction path are characterised. The calculations first confirm that the general mechanism proposed for other alcohol dehydrogenases is energetically viable. In this mechanism, a proton is first transferred from the substrate to a histidine residue at the surface, followed by a hydride transfer to the NADP cofactor. The calculated overall energy barrier is consistent with the measured rate constant. Very importantly, the calculations are able to reproduce and rationalise the enantioselectivity of the enzyme for both substrates. The detailed characterisation of the energies and geometries of the involved transition states will be valuable in the rational engineering of TbSADH to expand its utility in biocatalysis.
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Affiliation(s)
- Sara Moa
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Fahmi Himo
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden.
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26
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Plapp BV, Savarimuthu BR, Ferraro DJ, Rubach JK, Brown EN, Ramaswamy S. Horse Liver Alcohol Dehydrogenase: Zinc Coordination and Catalysis. Biochemistry 2017. [PMID: 28640600 PMCID: PMC5518280 DOI: 10.1021/acs.biochem.7b00446] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
During catalysis
by liver alcohol dehydrogenase (ADH), a water
bound to the catalytic zinc is replaced by the oxygen of the substrates.
The mechanism might involve a pentacoordinated zinc or a double-displacement
reaction with participation by a nearby glutamate residue, as suggested
by studies of human ADH3, yeast ADH1, and some other tetrameric ADHs.
Zinc coordination and participation of water in the enzyme mechanism
were investigated by X-ray crystallography. The apoenzyme and its
complex with adenosine 5′-diphosphoribose have an open protein
conformation with the catalytic zinc in one position, tetracoordinated
by Cys-46, His-67, Cys-174, and a water molecule. The bidentate chelators
2,2′-bipyridine and 1,10-phenanthroline displace the water
and form a pentacoordinated zinc. The enzyme–NADH complex has
a closed conformation similar to that of ternary complexes with coenzyme
and substrate analogues; the coordination of the catalytic zinc is
similar to that found in the apoenzyme, except that a minor, alternative
position for the catalytic zinc is ∼1.3 Å from the major
position and closer to Glu-68, which could form the alternative coordination
to the catalytic zinc. Complexes with NADH and N-1-methylhexylformamide
or N-benzylformamide (or with NAD+ and
fluoro alcohols) have the classical tetracoordinated zinc, and no
water is bound to the zinc or the nicotinamide rings. The major forms
of the enzyme in the mechanism have a tetracoordinated zinc, where
the carboxylate group of Glu-68 could participate in the exchange
of water and substrates on the zinc. Hydride transfer in the Michaelis
complexes does not involve a nearby water.
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Affiliation(s)
- Bryce V Plapp
- Department of Biochemistry, The University of Iowa , Iowa City, Iowa 52242, United States
| | - Baskar Raj Savarimuthu
- Department of Biochemistry, The University of Iowa , Iowa City, Iowa 52242, United States
| | - Daniel J Ferraro
- Department of Biochemistry, The University of Iowa , Iowa City, Iowa 52242, United States
| | - Jon K Rubach
- Department of Biochemistry, The University of Iowa , Iowa City, Iowa 52242, United States
| | - Eric N Brown
- Department of Biochemistry, The University of Iowa , Iowa City, Iowa 52242, United States
| | - S Ramaswamy
- Department of Biochemistry, The University of Iowa , Iowa City, Iowa 52242, United States
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27
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DFT-based prediction of reactivity of short-chain alcohol dehydrogenase. J Comput Aided Mol Des 2017; 31:587-602. [PMID: 28550607 PMCID: PMC5487757 DOI: 10.1007/s10822-017-0026-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/20/2017] [Indexed: 01/05/2023]
Abstract
The reaction mechanism of ketone reduction by short chain dehydrogenase/reductase, (S)-1-phenylethanol dehydrogenase from Aromatoleum aromaticum, was studied with DFT methods using cluster model approach. The characteristics of the hydride transfer process were investigated based on reaction of acetophenone and its eight structural analogues. The results confirmed previously suggested concomitant transfer of hydride from NADH to carbonyl C atom of the substrate with proton transfer from Tyr to carbonyl O atom. However, additional coupled motion of the next proton in the proton-relay system, between O2′ ribose hydroxyl and Tyr154 was observed. The protonation of Lys158 seems not to affect the pKa of Tyr154, as the stable tyrosyl anion was observed only for a neutral Lys158 in the high pH model. The calculated reaction energies and reaction barriers were calibrated by calorimetric and kinetic methods. This allowed an excellent prediction of the reaction enthalpies (R2 = 0.93) and a good prediction of the reaction kinetics (R2 = 0.89). The observed relations were validated in prediction of log Keq obtained for real whole-cell reactor systems that modelled industrial synthesis of S-alcohols.
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28
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Xiong J, Xu D. Insights into the Catalytic Mechanism of Unsaturated Glucuronyl Hydrolase of Bacillus sp. GL1. J Phys Chem B 2017; 121:931-941. [DOI: 10.1021/acs.jpcb.6b10501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jing Xiong
- MOE Key Laboratory of Green Chemistry, College of Chemistry and ‡Geonome Research
Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610064, People’s Republic of China
| | - Dingguo Xu
- MOE Key Laboratory of Green Chemistry, College of Chemistry and ‡Geonome Research
Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610064, People’s Republic of China
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29
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Empirical Force Fields for Mechanistic Studies of Chemical Reactions in Proteins. Methods Enzymol 2016. [PMID: 27498633 DOI: 10.1016/bs.mie.2016.05.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Following chemical reactions in atomistic detail is one of the most challenging aspects of current computational approaches to chemistry. In this chapter the application of adiabatic reactive MD (ARMD) and its multistate version (MS-ARMD) are discussed. Both methods allow to study bond-breaking and bond-forming processes in chemical and biological processes. Particular emphasis is put on practical aspects for applying the methods to investigate the dynamics of chemical reactions. The chapter closes with an outlook of possible generalizations of the methods discussed.
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30
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Affiliation(s)
- C. Satheesan Babu
- Institute
of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan R.O.C
| | - Carmay Lim
- Institute
of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan R.O.C
- Department
of Chemistry, National Tsing-Hua University, Hsinchu 300, Taiwan R.O.C
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31
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Activity prediction of substrates in NADH-dependent carbonyl reductase by docking requires catalytic constraints and charge parameterization of catalytic zinc environment. J Comput Aided Mol Des 2015; 29:1057-69. [PMID: 26530855 DOI: 10.1007/s10822-015-9878-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 10/30/2015] [Indexed: 12/27/2022]
Abstract
Molecular docking of substrates is more challenging compared to inhibitors as the reaction mechanism has to be considered. This becomes more pronounced for zinc-dependent enzymes since the coordination state of the catalytic zinc ion is of greater importance. In order to develop a predictive substrate docking protocol, we have performed molecular docking studies of diketone substrates using the catalytic state of carbonyl reductase 2 from Candida parapsilosis (CPCR2). Different docking protocols using two docking methods (AutoDock Vina and AutoDock4.2) with two different sets of atomic charges (AM1-BCC and HF-RESP) for catalytic zinc environment and substrates as well as two sets of vdW parameters for zinc ion were examined. We have selected the catalytic binding pose of each substrate by applying mechanism based distance criteria. To compare the performance of the docking protocols, the correlation plots for the binding energies of these catalytic poses were obtained against experimental Vmax values of the 11 diketone substrates for CPCR2. The best correlation of 0.73 was achieved with AutoDock4.2 while treating catalytic zinc ion in optimized non-bonded (NBopt) state with +1.01 charge on the zinc ion, compared to 0.36 in non-bonded (+2.00 charge on the zinc ion) state. These results indicate the importance of catalytic constraints and charge parameterization of catalytic zinc environment for the prediction of substrate activity in zinc-dependent enzymes by molecular docking. The developed predictive docking protocol described here is in principle generally applicable for the efficient in silico substrate spectra characterization of zinc-dependent ADH.
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32
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Vardi-Kilshtain A, Nitoker N, Major DT. Nuclear quantum effects and kinetic isotope effects in enzyme reactions. Arch Biochem Biophys 2015; 582:18-27. [DOI: 10.1016/j.abb.2015.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/02/2015] [Accepted: 03/03/2015] [Indexed: 11/28/2022]
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33
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Isaev AN. Keto-enol tautomerization of a peptide group with proton transfer through a water bridge. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2015. [DOI: 10.1134/s0036024415080154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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34
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Dhoke GV, Davari MD, Schwaneberg U, Bocola M. QM/MM Calculations Revealing the Resting and Catalytic States in Zinc-Dependent Medium-Chain Dehydrogenases/Reductases. ACS Catal 2015. [DOI: 10.1021/cs501524k] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Gaurao V. Dhoke
- RWTH Aachen University, Chair of Biotechnology, Worringer Weg 3, D-52074 Aachen, Germany
| | - Mehdi D. Davari
- RWTH Aachen University, Chair of Biotechnology, Worringer Weg 3, D-52074 Aachen, Germany
| | - Ulrich Schwaneberg
- RWTH Aachen University, Chair of Biotechnology, Worringer Weg 3, D-52074 Aachen, Germany
| | - Marco Bocola
- RWTH Aachen University, Chair of Biotechnology, Worringer Weg 3, D-52074 Aachen, Germany
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35
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Sadiq SK, Coveney PV. Computing the Role of Near Attack Conformations in an Enzyme-Catalyzed Nucleophilic Bimolecular Reaction. J Chem Theory Comput 2014; 11:316-24. [DOI: 10.1021/ct5008845] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- S. Kashif Sadiq
- Infection
Biology Unit, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), C/Doctor Aiguader 88, 08003 Barcelona, Spain
| | - Peter V. Coveney
- Centre
for Computational Science, Department of Chemistry, University College London, London WC1H 0AJ, United Kingdom
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36
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Fitzpatrick PF. Combining solvent isotope effects with substrate isotope effects in mechanistic studies of alcohol and amine oxidation by enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1854:1746-55. [PMID: 25448013 DOI: 10.1016/j.bbapap.2014.10.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/17/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
Abstract
Oxidation of alcohols and amines is catalyzed by multiple families of flavin- and pyridine nucleotide-dependent enzymes. Measurement of solvent isotope effects provides a unique mechanistic probe of the timing of the cleavage of the OH and NH bonds, necessary information for a complete description of the catalytic mechanism. The inherent ambiguities in interpretation of solvent isotope effects can be significantly decreased if isotope effects arising from isotopically labeled substrates are measured in combination with solvent isotope effects. The application of combined solvent and substrate (mainly deuterium) isotope effects to multiple enzymes is described here to illustrate the range of mechanistic insights that such an approach can provide. This article is part of a Special Issue entitled: Enzyme Transition States from Theory and Experiment.
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Affiliation(s)
- Paul F Fitzpatrick
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78212, USA.
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37
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Lu X, Gaus M, Elstner M, Cui Q. Parametrization of DFTB3/3OB for magnesium and zinc for chemical and biological applications. J Phys Chem B 2014; 119:1062-82. [PMID: 25178644 PMCID: PMC4306495 DOI: 10.1021/jp506557r] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
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We report the parametrization of
the approximate density functional
theory, DFTB3, for magnesium and zinc for chemical and biological
applications. The parametrization strategy follows that established
in previous work that parametrized several key main group elements
(O, N, C, H, P, and S). This 3OB set of parameters can thus be used
to study many chemical and biochemical systems. The parameters are
benchmarked using both gas-phase and condensed-phase systems. The
gas-phase results are compared to DFT (mostly B3LYP), ab initio (MP2 and G3B3), and PM6, as well as to a previous DFTB parametrization
(MIO). The results indicate that DFTB3/3OB is particularly successful
at predicting structures, including rather complex dinuclear metalloenzyme
active sites, while being semiquantitative (with a typical mean absolute
deviation (MAD) of ∼3–5 kcal/mol) for energetics. Single-point
calculations with high-level quantum mechanics (QM) methods generally
lead to very satisfying (a typical MAD of ∼1 kcal/mol) energetic
properties. DFTB3/MM simulations for solution and two enzyme systems
also lead to encouraging structural and energetic properties in comparison
to available experimental data. The remaining limitations of DFTB3,
such as the treatment of interaction between metal ions and highly
charged/polarizable ligands, are also discussed.
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Affiliation(s)
- Xiya Lu
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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38
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Kiefer PM, Pines E, Pines D, Hynes JT. Solvent-Induced Red-Shifts for the Proton Stretch Vibrational Frequency in a Hydrogen-Bonded Complex. 1. A Valence Bond-Based Theoretical Approach. J Phys Chem B 2014; 118:8330-51. [DOI: 10.1021/jp501815j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Philip M. Kiefer
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Ehud Pines
- Department
of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Be’er
Sheva, 84105, Israel
| | - Dina Pines
- Department
of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Be’er
Sheva, 84105, Israel
| | - James T. Hynes
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
- Chemistry
Department, École Normale Supérieure, UMR ENS-CNRS-UPMC 8640, 24 rue Lhomond, 75005 Paris, France
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39
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Affiliation(s)
- Joshua P. Layfield
- Department of Chemistry, 600 South Mathews Avenue, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Sharon Hammes-Schiffer
- Department of Chemistry, 600 South Mathews Avenue, University of Illinois at Urbana-Champaign, Urbana, IL 61801
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40
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Yahashiri A, Rubach JK, Plapp BV. Effects of cavities at the nicotinamide binding site of liver alcohol dehydrogenase on structure, dynamics and catalysis. Biochemistry 2014; 53:881-94. [PMID: 24437493 PMCID: PMC3969020 DOI: 10.1021/bi401583f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
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A role
for protein dynamics in enzymatic catalysis of hydrogen
transfer has received substantial scientific support, but the connections
between protein structure and catalysis remain to be established.
Valine residues 203 and 207 are at the binding site for the nicotinamide
ring of the coenzyme in liver alcohol dehydrogenase and have been
suggested to facilitate catalysis with “protein-promoting vibrations”
(PPV). We find that the V207A substitution has small effects on steady-state
kinetic constants and the rate of hydrogen transfer; the introduced
cavity is empty and is tolerated with minimal effects on structure
(determined at 1.2 Å for the complex with NAD+ and
2,3,4,5,6-pentafluorobenzyl alcohol). Thus, no evidence is found to
support a role for Val-207 in the dynamics of catalysis. The protein
structures and ligand geometries (including donor–acceptor
distances) in the V203A enzyme complexed with NAD+ and
2,3,4,5,6-pentafluorobenzyl alcohol or 2,2,2-trifluoroethanol (determined
at 1.1 Å) are very similar to those for the wild-type enzyme,
except that the introduced cavity accommodates a new water molecule
that contacts the nicotinamide ring. The structures of the V203A enzyme
complexes suggest, in contrast to previous studies, that the diminished
tunneling and decreased rate of hydride transfer (16-fold, relative
to that of the wild-type enzyme) are not due to differences in ground-state
ligand geometries. The V203A substitution may alter the PPV and the
reorganization energy for hydrogen transfer, but the protein scaffold
and equilibrium thermal motions within the Michaelis complex may be
more significant for enzyme catalysis.
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Affiliation(s)
- Atsushi Yahashiri
- Department of Biochemistry, The University of Iowa , Iowa City, Iowa 52242-1109, United States
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41
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Experimental and theoretical studies of enzyme-catalyzed hydrogen-transfer reactions. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2012. [PMID: 22607755 DOI: 10.1016/b978-0-12-398312-1.00006-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
The mechanisms of enzyme-catalyzed reactions are medicinally important and present a fascinating intellectual challenge. Many experimental and theoretical techniques can shed light on these mechanisms, and here, we shall focus on the utility of kinetic isotope effects (KIEs) to study enzymatic reactions that involve hydrogen transfers. We will provide a short background on the prevailing models to interpret KIEs and then present more detailed reviews of two model enzymes: alcohol dehydrogenase and thymidylate synthase. These two examples provide a context to describe the types of experiments and theoretical calculations that drive this field forward and the kind of information each can furnish. We emphasize the importance of cooperation between experimentalists and theoreticians to continue the progress toward a comprehensive theory of enzyme catalysis.
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42
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Haines BE, Steussy CN, Stauffacher CV, Wiest O. Molecular modeling of the reaction pathway and hydride transfer reactions of HMG-CoA reductase. Biochemistry 2012; 51:7983-95. [PMID: 22971202 PMCID: PMC3522576 DOI: 10.1021/bi3008593] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
HMG-CoA reductase catalyzes the four-electron reduction of HMG-CoA to mevalonate and is an enzyme of considerable biomedical relevance because of the impact of its statin inhibitors on public health. Although the reaction has been studied extensively using X-ray crystallography, there are surprisingly no computational studies that test the mechanistic hypotheses suggested for this complex reaction. Theozyme and quantum mechanical (QM)/molecular mechanical (MM) calculations up to the B3LYP/6-31g(d,p)//B3LYP/6-311++g(2d,2p) level of theory were employed to generate an atomistic description of the enzymatic reaction process and its energy profile. The models generated here predict that the catalytically important Glu83 is protonated prior to hydride transfer and that it acts as the general acid or base in the reaction. With Glu83 protonated, the activation energies calculated for the sequential hydride transfer reactions, 21.8 and 19.3 kcal/mol, are in qualitative agreement with the experimentally determined rate constant for the entire reaction (1 s(-1) to 1 min(-1)). When Glu83 is not protonated, the first hydride transfer reaction is predicted to be disfavored by >20 kcal/mol, and the activation energy is predicted to be higher by >10 kcal/mol. While not involved in the reaction as an acid or base, Lys267 is critical for stabilization of the transition state in forming an oxyanion hole with the protonated Glu83. Molecular dynamics simulations and MM/Poisson-Boltzmann surface area free energy calculations predict that the enzyme active site stabilizes the hemithioacetal intermediate better than the aldehyde intermediate. This suggests a mechanism in which cofactor exchange occurs before the breakdown of the hemithioacetal. Slowing the conversion to aldehyde would provide the enzyme with a mechanism to protect it from solvent and explain why the free aldehyde is not observed experimentally. Our results support the hypothesis that the pK(a) of an active site acidic group is modulated by the redox state of the cofactor. The oxidized cofactor and deprotonated Glu83 are closer in space after hydride transfer, indicating that indeed the cofactor may influence the pK(a) of Glu83 through an electrostatic interaction. The enzyme is able to catalyze the transfer of a hydride to the structurally and electronically distinct substrates by maintaining the general shape of the active site and adjusting the electrostatic environment through acid-base chemistry. Our results are in good agreement with the well-studied hydride transfer reactions catalyzed by liver alcohol dehydrogenase in calculated energy profile and reaction geometries despite different mechanistic functionalities.
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Affiliation(s)
- Brandon E. Haines
- Department of Chemistry and Biochemistry, Notre Dame University, Notre Dame, Indiana 46556
| | - C. Nicklaus Steussy
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907
| | | | - Olaf Wiest
- Department of Chemistry and Biochemistry, Notre Dame University, Notre Dame, Indiana 46556
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43
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Ab initio, density functional theory, and semi-empirical calculations. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2012; 924:3-27. [PMID: 23034743 DOI: 10.1007/978-1-62703-017-5_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This chapter introduces the theory and applications of commonly used methods of electronic structure calculation, with particular emphasis on methods applicable for modelling biomolecular systems. This chapter is sectioned as follows. We start by presenting ab initio methods, followed by a treatment of density functional theory (DFT) and some recent advances in semi-empirical methods. Treatment of excited states as well as basis sets are also presented.
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44
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Roston D, Cheatum CM, Kohen A. Hydrogen donor-acceptor fluctuations from kinetic isotope effects: a phenomenological model. Biochemistry 2012; 51:6860-70. [PMID: 22857146 PMCID: PMC3448806 DOI: 10.1021/bi300613e] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Kinetic isotope effects (KIEs) and their temperature dependence can probe the structural and dynamic nature of enzyme-catalyzed proton or hydride transfers. The molecular interpretation of their temperature dependence requires expensive and specialized quantum mechanics/molecular mechanics (QM/MM) calculations to provide a quantitative molecular understanding. Currently available phenomenological models use a nonadiabatic assumption that is not appropriate for most hydride and proton-transfer reactions, while others require more parameters than the experimental data justify. Here we propose a phenomenological interpretation of KIEs based on a simple method to quantitatively link the size and temperature dependence of KIEs to a conformational distribution of the catalyzed reaction. This model assumes adiabatic hydrogen tunneling, and by fitting experimental KIE data, the model yields a population distribution for fluctuations of the distance between donor and acceptor atoms. Fits to data from a variety of proton and hydride transfers catalyzed by enzymes and their mutants, as well as nonenzymatic reactions, reveal that steeply temperature-dependent KIEs indicate the presence of at least two distinct conformational populations, each with different kinetic behaviors. We present the results of these calculations for several published cases and discuss how the predictions of the calculations might be experimentally tested. This analysis does not replace molecular QM/MM investigations, but it provides a fast and accessible way to quantitatively interpret KIEs in the context of a Marcus-like model.
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Affiliation(s)
- Daniel Roston
- Department of Chemistry, University of Iowa, Iowa City, IA 52242
| | | | - Amnon Kohen
- Department of Chemistry, University of Iowa, Iowa City, IA 52242
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45
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Islam SM, Roy PN. Performance of the SCC-DFTB Model for Description of Five-Membered Ring Carbohydrate Conformations: Comparison to Force Fields, High-Level Electronic Structure Methods, and Experiment. J Chem Theory Comput 2012; 8:2412-23. [DOI: 10.1021/ct200789w] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Shahidul M. Islam
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - Pierre-Nicholas Roy
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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46
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Plapp BV, Ramaswamy S. Atomic-resolution structures of horse liver alcohol dehydrogenase with NAD(+) and fluoroalcohols define strained Michaelis complexes. Biochemistry 2012; 51:4035-48. [PMID: 22531044 DOI: 10.1021/bi300378n] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Structures of horse liver alcohol dehydrogenase complexed with NAD(+) and unreactive substrate analogues, 2,2,2-trifluoroethanol or 2,3,4,5,6-pentafluorobenzyl alcohol, were determined at 100 K at 1.12 or 1.14 Å resolution, providing estimates of atomic positions with overall errors of ~0.02 Å, the geometry of ligand binding, descriptions of alternative conformations of amino acid residues and waters, and evidence of a strained nicotinamide ring. The four independent subunits from the two homodimeric structures differ only slightly in the peptide backbone conformation. Alternative conformations for amino acid side chains were identified for 50 of the 748 residues in each complex, and Leu-57 and Leu-116 adopt different conformations to accommodate the different alcohols at the active site. Each fluoroalcohol occupies one position, and the fluorines of the alcohols are well-resolved. These structures closely resemble the expected Michaelis complexes with the pro-R hydrogens of the methylene carbons of the alcohols directed toward the re face of C4N of the nicotinamide rings with a C-C distance of 3.40 Å. The oxygens of the alcohols are ligated to the catalytic zinc at a distance expected for a zinc alkoxide (1.96 Å) and participate in a low-barrier hydrogen bond (2.52 Å) with the hydroxyl group of Ser-48 in a proton relay system. As determined by X-ray refinement with no restraints on bond distances and planarity, the nicotinamide rings in the two complexes are slightly puckered (quasi-boat conformation, with torsion angles of 5.9° for C4N and 4.8° for N1N relative to the plane of the other atoms) and have bond distances that are somewhat different compared to those found for NAD(P)(+). It appears that the nicotinamide ring is strained toward the transition state on the path to alcohol oxidation.
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Affiliation(s)
- Bryce V Plapp
- Department of Biochemistry, The University of Iowa, Iowa City, IA 52242, USA.
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47
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Cazade PA, Huang J, Yosa J, Szymczak JJ, Meuwly M. Atomistic simulations of reactive processes in the gas- and condensed-phase. INT REV PHYS CHEM 2012. [DOI: 10.1080/0144235x.2012.694694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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48
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FORMANECK MARKS, LI GUOHUI, ZHANG XIAODONG, CUI QIANG. CALCULATING ACCURATE REDOX POTENTIALS IN ENZYMES WITH A COMBINED QM/MM FREE ENERGY PERTURBATION APPROACH. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2012. [DOI: 10.1142/s0219633602000075] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An approach for computing accurate redox potentials in enzymes is developed based on the free energy perturbation technique in a QM/MM framework. With an appropriate choice of the QM level and QM/MM coupling scheme, the intermolecular interaction between the redox center and the protein environment can be adequately described; the speed of QM/MM methods also allows a sufficient configurational sampling for the convergence of free energy derivatives. Following the implementation into the simulation package CHARMM, the method was tested with an application to the first reduction potential of FAD in cholesterol oxidase (Chox). In addition to an accurate QM level and adequate conformational samplings, the effect of long-range electrostatic interactions due to the bulk solvent was also found to be essential. Using a semi-empirical density functional theory (SCC-DFTB) as the QM level, and a multi-stage charge-scaling scheme based on Poisson–Boltzmann calculations for the solvation effect, satisfactory agreements with experimental measurements were obtained. The study of Chox also indicates that large errors in the calculated redox potential might arise if changes in the conformational properties of the protein during the redox process are not taken into account, such as in energy minimization type of studies based on only the X-ray structure of the enzyme in one redox state.
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Affiliation(s)
- MARK S. FORMANECK
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison 1101 University Ave, Madison, WI 53706, USA
| | - GUOHUI LI
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison 1101 University Ave, Madison, WI 53706, USA
| | - XIAODONG ZHANG
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison 1101 University Ave, Madison, WI 53706, USA
| | - QIANG CUI
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison 1101 University Ave, Madison, WI 53706, USA
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49
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WITEK HENRYKA, MOROKUMA KEIJI, STRADOMSKA ANNA. MODELING VIBRATIONAL SPECTRA USING THE SELF-CONSISTENT CHARGE DENSITY-FUNCTIONAL TIGHT-BINDING METHOD II: INFRARED SPECTRA. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633605001763] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We present an extended self-consistent charge density-functional tight-binding (SCC-DFTB) method that allows for computing vibrational infrared spectra. The extension is based on introducing an additional term in the SCC-DFTB energy formula that describes effectively the interaction of external electric field with molecular electron density distribution. The extended SCC-DFTB method is employed to model vibrational infrared spectra of 16 organic molecules. The calculated spectra are compared to experiment and to spectra obtained with density functional theory. For most of the molecules, the SCC-DFTB method reproduces the experimental spectra in a very satisfactory manner. We discuss the drawbacks and possible applications of this new scheme.
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Affiliation(s)
- HENRYK A. WITEK
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - KEIJI MOROKUMA
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - ANNA STRADOMSKA
- K. Gumiǹski Department of Theoretical Chemistry, Jagiellonian University, Ingardena 3, 30-060 Cracow, Poland
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50
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Ibrahim MAA. Performance Assessment of Semiempirical Molecular Orbital Methods in Describing Halogen Bonding: Quantum Mechanical and Quantum Mechanical/Molecular Mechanical-Molecular Dynamics Study. J Chem Inf Model 2011; 51:2549-59. [DOI: 10.1021/ci2002582] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mahmoud A. A. Ibrahim
- School of Chemistry, University of Manchester, Oxford Road, Manchester M139PL, United Kingdom
- Chemistry Department, Faculty of Science, Minia University, Minia 61519, Egypt
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