1
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Feng J, Jin R, Cheng S, Li H, Wang X, Chen K. Establishing an Artificial Pathway for the Biosynthesis of Octopamine and Synephrine. ACS Synth Biol 2024; 13:1762-1772. [PMID: 38815614 DOI: 10.1021/acssynbio.4c00082] [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] [Indexed: 06/01/2024]
Abstract
In this study, we designed an artificial pathway composed of tyramine β-hydroxylase (TBH) and phenylethanolamine N-methyltransferase (PNMT) for the biosynthesis of both octopamine and synephrine. As most TBH and PNMT originate from eukaryotic animals and plants, the heterologous expression and identification of functional TBH and PNMT are critical for establishing the pathway in mode microorganisms like Escherichia coli. Here, three TBHs were evaluated, and only TBH from Drosophila melanogaster was successfully expressed in the soluble form in E. coli. Its expression was promoted by evaluating the effects of different expression strategies. The specific enzyme activity of TBH was optimized up to 229.50 U·g-1, and the first step in the biosynthetic pathway was successfully established and converted tyramine to synthesize 0.10 g/L of octopamine. Furthermore, the second step to produce synephrine from octopamine was developed by screening PNMT, enhancing enzyme activity, and optimizing reaction conditions, with a maximum synephrine production of 2.02 g/L. Finally, based on the optimization of the reaction conditions for each individual reaction, the one-pot cascade reaction for synthesizing synephrine from tyramine was constructed by combining the TBH and PNMT. The synthetic synephrine reached 30.05 mg/L with tyramine as substrate in the two-step enzyme cascade system. With further optimization and amplification, the titers of octopamine and synephrine were increased to 0.45 and 0.20 g/L, respectively, with tyramine as substrate. This work was the first achievement of the biosynthesis of octopamine and synephrine to date.
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Affiliation(s)
- Jiao Feng
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, People's Republic of China
| | - Runyuan Jin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, People's Republic of China
| | - Shasha Cheng
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, People's Republic of China
| | - Hui Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, People's Republic of China
| | - Xin Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, People's Republic of China
| | - Kequan Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, People's Republic of China
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2
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Huang J, Xie X, Zheng Z, Ye L, Wang P, Xu L, Wu Y, Yan J, Yang M, Yan Y. De Novo Computational Design of a Lipase with Hydrolysis Activity towards Middle-Chained Fatty Acid Esters. Int J Mol Sci 2023; 24:ijms24108581. [PMID: 37239928 DOI: 10.3390/ijms24108581] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Innovations in biocatalysts provide great prospects for intolerant environments or novel reactions. Due to the limited catalytic capacity and the long-term and labor-intensive characteristics of mining enzymes with the desired functions, de novo enzyme design was developed to obtain industrial application candidates in a rapid and convenient way. Here, based on the catalytic mechanisms and the known structures of proteins, we proposed a computational protein design strategy combining de novo enzyme design and laboratory-directed evolution. Starting with the theozyme constructed using a quantum-mechanical approach, the theoretical enzyme-skeleton combinations were assembled and optimized via the Rosetta "inside-out" protocol. A small number of designed sequences were experimentally screened using SDS-PAGE, mass spectrometry and a qualitative activity assay in which the designed enzyme 1a8uD1 exhibited a measurable hydrolysis activity of 24.25 ± 0.57 U/g towards p-nitrophenyl octanoate. To improve the activity of the designed enzyme, molecular dynamics simulations and the RosettaDesign application were utilized to further optimize the substrate binding mode and amino acid sequence, thus keeping the residues of theozyme intact. The redesigned lipase 1a8uD1-M8 displayed enhanced hydrolysis activity towards p-nitrophenyl octanoate-3.34 times higher than that of 1a8uD1. Meanwhile, the natural skeleton protein (PDB entry 1a8u) did not display any hydrolysis activity, confirming that the hydrolysis abilities of the designed 1a8uD1 and the redesigned 1a8uD1-M8 were devised from scratch. More importantly, the designed 1a8uD1-M8 was also able to hydrolyze the natural middle-chained substrate (glycerol trioctanoate), for which the activity was 27.67 ± 0.69 U/g. This study indicates that the strategy employed here has great potential to generate novel enzymes exhibiting the desired reactions.
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Affiliation(s)
- Jinsha Huang
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaoman Xie
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhen Zheng
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Luona Ye
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Pengbo Wang
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Li Xu
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ying Wu
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jinyong Yan
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Min Yang
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yunjun Yan
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
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3
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Díaz-Cervantes E, Robles J, Solà M, Swart M. The peptide bond rupture mechanism in the serine proteases: an in silico study based on sequential scale models. Phys Chem Chem Phys 2023; 25:8043-8049. [PMID: 36876585 DOI: 10.1039/d2cp04872h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Given the importance of serine proteases for biochemical processes, we have studied the peptide bond rupture mechanism using three sequential scale models as representations of the KLK5 enzyme (a protein overexpressed in ovarian cancer). The first model contains the basic functional groups of the residues that conform to the catalytic triad present in serine proteases; the second model contains some additional residues and, finally, the last representation includes all atoms of the KLK5 protein together with 10.000 explicit water molecules. This separation into three scale models allows us to separate the intrinsic reactivity of the catalytic triad from the process taking place in the enzyme. The methodologies employed in this work include full DFT calculations with a dielectric continuum in the first two models and a multi-level setup with a Quantum Mechanics/Molecular Mechanics (QM/MM) partition in the whole protein system. Our results show that the peptide-bond rupture mechanism is a stepwise process involving two proton transfer reactions. The rate-determining step is the second proton transfer from the imidazole group to the amidic nitrogen of the substrate. In addition, we find that the simplest model does not provide accurate results compared to the full protein system. This can be attributed to the electronic stabilization conferred by the residues around the reaction site. Interestingly, the energy profile obtained with the second scale model with additional residues shows the same trends as the full system and could therefore be considered an appropriate model system. It could be used for studying the peptide bond rupture mechanism in case full QM/MM calculations cannot be performed, or as a rapid tool for screening purposes.
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Affiliation(s)
- Erik Díaz-Cervantes
- Departamento de Alimentos, Centro Interdisciplinario del Noreste, Universidad de Guanajuato, 37975 Tierra Blanca, Guanajuato, Mexico.,Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, 17003 Girona, Spain.
| | - Juvencio Robles
- Departamento de Farmacia, Universidad de Guanajuato, Noria Alta S/N, Gto. 36050, Guanajuato, Mexico
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, 17003 Girona, Spain.
| | - Marcel Swart
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, 17003 Girona, Spain. .,ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
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4
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Krivitskaya AV, Khrenova MG. Interplay between the Enamine and Imine Forms of the Hydrolyzed Imipenem in the Active Sites of Metallo-β-lactamases and in Water Solution. J Chem Inf Model 2022; 62:6519-6529. [PMID: 35758922 DOI: 10.1021/acs.jcim.2c00539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Deactivation of the β-lactam antibiotics in the active sites of the β-lactamases is among the main mechanisms of bacterial antibiotic resistance. As drugs of last resort, carbapenems are efficiently hydrolyzed by metallo-β-lactamases, presenting a serious threat to human health. Our study reveals mechanistic aspects of the imipenem hydrolysis by bizinc metallo-β-lactamases, NDM-1 and L1, belonging to the B1 and the B3 subclasses, respectively. The results of QM(PBE0-D3/6-31G**)/MM simulations show that the enamine product with the protonated nitrogen atom is formed as the major product in NDM-1 and as the only product in the L1 active site. In NDM-1, there is also another reaction pathway that leads to the formation of the (S)-enantiomer of the imine form of the hydrolyzed imipenem; this process occurs with the higher energy barriers. The absence of the second pathway in L1 is due to the different amino acid composition of the active site loop. In L1, the hydrophobic Pro226 residue is located above the pyrroline ring of imipenem that blocks protonation of the carbon atom. Electron density analysis is performed at the stationary points to compare reaction pathways in L1 and NDM-1. Tautomerization from the enamine to the imine form likely happens in solution after the dissociation of the hydrolyzed imipenem from the active site of the enzyme. Classical molecular dynamics simulations of the hydrolyzed imipenem in solution, both with the neutral enamine and the negatively charged N-C2-C3 fragment, demonstrate a huge diversity of conformations. The vast majority of conformations blocks the C3-atom from the side required for the (S)-imine formation upon tautomerization. Thus, according to our calculations, formation of the (R)-imine is more likely. QM(PBE0-D3/6-31G**)/MM molecular dynamics simulations of the hydrolyzed imipenem with the negatively charged N-C2-C3 fragment followed by the Laplacian bond order analysis demonstrate that the N═C2-C3- resonance structure is the most pronounced that facilitates formation of the imine form. The proposed mechanism of the enzymatic enamine formation and its subsequent tautomerization to the imine form in solution is in agreement with the recent spectroscopic and NMR studies.
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Affiliation(s)
- Alexandra V Krivitskaya
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Moscow 119071, Russia
| | - Maria G Khrenova
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Moscow 119071, Russia.,Department of Chemistry, Interdisciplinary Scientific and Educational School of Moscow University "Brain, Cognitive Systems, Artificial Intelligence", Lomonosov Moscow State University, Moscow 119991, Russia
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5
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Evolution of Ceftriaxone Resistance of Penicillin-Binding Proteins 2 Revealed by Molecular Modeling. Int J Mol Sci 2022; 24:ijms24010176. [PMID: 36613627 PMCID: PMC9820184 DOI: 10.3390/ijms24010176] [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: 11/23/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
Penicillin-binding proteins 2 (PBP2) are critically important enzymes in the formation of the bacterial cell wall. Inhibition of PBP2 is utilized in the treatment of various diseases, including gonorrhea. Ceftriaxone is the only drug used to treat gonorrhea currently, and recent growth in PBP2 resistance to this antibiotic is a serious threat to human health. Our study reveals mechanistic aspects of the inhibition reaction of PBP2 from the wild-type FA19 strain and mutant 35/02 and H041 strains of Neisseria Gonorrhoeae by ceftriaxone. QM(PBE0-D3/6-31G**)/MM MD simulations show that the reaction mechanism for the wild-type PBP2 consists of three elementary steps including nucleophilic attack, C-N bond cleavage in the β-lactam ring and elimination of the leaving group in ceftriaxone. In PBP2 from the mutant strains, the second and third steps occur simultaneously. For all considered systems, the acylation rate is determined by the energy barrier of the first step that increases in the order of PBP2 from FA19, 35/02 and H041 strains. Dynamic behavior of ES complexes is analyzed using geometry and electron density features including Fukui electrophilicity index and Laplacian of electron density maps. It reveals that more efficient activation of the carbonyl group of the antibiotic leads to the lower energy barrier of nucleophilic attack and larger stabilization of the first reaction intermediate. Dynamical network analysis of MD trajectories explains the differences in ceftriaxone binding affinity: in PBP2 from the wild-type strain, the β3-β4 loop conformation facilitates substrate binding, whereas in PBP2 from the mutant strains, it exists in the conformation that is unfavorable for complex formation. Thus, we clarify that the experimentally observed decrease in the second-order rate constant of acylation (k2/KS) in PBP2 from the mutant strains is due to both a decrease in the acylation rate constant k2 and an increase in the dissociation constant KS.
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6
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Mokhtari DA, Appel MJ, Fordyce PM, Herschlag D. High throughput and quantitative enzymology in the genomic era. Curr Opin Struct Biol 2021; 71:259-273. [PMID: 34592682 PMCID: PMC8648990 DOI: 10.1016/j.sbi.2021.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 07/23/2021] [Indexed: 12/28/2022]
Abstract
Accurate predictions from models based on physical principles are the ultimate metric of our biophysical understanding. Although there has been stunning progress toward structure prediction, quantitative prediction of enzyme function has remained challenging. Realizing this goal will require large numbers of quantitative measurements of rate and binding constants and the use of these ground-truth data sets to guide the development and testing of these quantitative models. Ground truth data more closely linked to the underlying physical forces are also desired. Here, we describe technological advances that enable both types of ground truth measurements. These advances allow classic models to be tested, provide novel mechanistic insights, and place us on the path toward a predictive understanding of enzyme structure and function.
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Affiliation(s)
- D A Mokhtari
- Department of Biochemistry, Stanford University, Stanford, CA, 94305, USA
| | - M J Appel
- Department of Biochemistry, Stanford University, Stanford, CA, 94305, USA
| | - P M Fordyce
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA, 94305, USA; Department of Genetics, Stanford University, Stanford, CA, 94305, USA; Chan Zuckerberg Biohub San Francisco, CA, 94110, USA.
| | - D Herschlag
- Department of Biochemistry, Stanford University, Stanford, CA, 94305, USA; Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA, 94305, USA.
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7
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Bajaj S, Jain S, Vyas P, Bawa S, Vohora D. The role of endocannabinoid pathway in the neuropathology of Alzheimer's disease: Can the inhibitors of MAGL and FAAH prove to be potential therapeutic targets against the cognitive impairment associated with Alzheimer's disease? Brain Res Bull 2021; 174:305-322. [PMID: 34217798 DOI: 10.1016/j.brainresbull.2021.06.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease is a neurodegenerative disease characterized by progressive decline of cognitive function in combination with neuronal death. Current approved treatment target single dysregulated pathway instead of multiple mechanism, resulting in lack of efficacy in slowing down disease progression. The proclivity of endocannabinoid system to exert neuroprotective action and mitigate symptoms of neurodegeneration condition has received substantial interest. Growing evidence suggest the endocannabinoids (eCB) system, viz. anadamide (AEA) and arachidonoyl glycerol (2-AG), as potential therapeutic targets with the ability to modify Alzheimer's pathology by targeting the inflammatory, neurodegenerative and cognitive aspects of the disease. In order to modulate endocannabinoid system, number of agents have been reported amongst which are inhibitors of the monoacylglycerol (MAGL) and fatty acid amide hydrolase (FAAH), the enzymes that hydrolyses 2-AG and AEA respectively. However, little is known regarding the exact mechanistic signalling and their effects on pathophysiology and cognitive decline associated with Alzheimer's disease. Both MAGL and FAAH inhibitors possess fascinating properties that may offer a multi-faceted approach for the treatment of Alzheimer's disease such as potential to protect neurons from deleterious effect of amyloid-β, reducing phosphorylation of tau, reducing amyloid-β induced oxidative stress, stimulating neurotrophin to support brain intrinsic repair mechanism etc. Based on empirical evidence, MAGL and FAAH inhibitors might have potential for therapeutic efficacy against cognitive impairment associated with Alzheimer's disease. The aim of this review is to summarize the experimental studies demonstrating the polyvalent properties of MAGL or FAAH inhibitor compounds for the treatment of Alzheimer's disease, and also effect of these on learning and types of memories, which together encourage to study these compounds over other therapeutics targets. Further research in this direction would enhance the molecular mechanisms and development of applicable interventions for the treatment of Alzheimer's disease, which nevertheless stay as the primary unmet need.
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Affiliation(s)
- Shivanshu Bajaj
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
| | - Shreshta Jain
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
| | - Preeti Vyas
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
| | - Sandhya Bawa
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
| | - Divya Vohora
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India.
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8
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Abstract
Enzymes are predominantly proteins able to effectively and selectively catalyze highly complex biochemical reactions in mild reaction conditions. Nevertheless, they are limited to the arsenal of reactions that have emerged during natural evolution in compliance with their intrinsic nature, three-dimensional structures and dynamics. They optimally work in physiological conditions for a limited range of reactions, and thus exhibit a low tolerance for solvent and temperature conditions. The de novo design of synthetic highly stable enzymes able to catalyze a broad range of chemical reactions in variable conditions is a great challenge, which requires the development of programmable and finely tunable artificial tools. Interestingly, over the last two decades, chemists developed protein secondary structure mimics to achieve some desirable features of proteins, which are able to interfere with the biological processes. Such non-natural oligomers, so called foldamers, can adopt highly stable and predictable architectures and have extensively demonstrated their attractiveness for widespread applications in fields from biomedical to material science. Foldamer science was more recently considered to provide original solutions to the de novo design of artificial enzymes. This review covers recent developments related to peptidomimetic foldamers with catalytic properties and the principles that have guided their design.
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9
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Cortés-García CJ, Chacón-García L, Mejía-Benavides JE, Díaz-Cervantes E. Tackling the SARS-CoV-2 main protease using hybrid derivatives of 1,5-disubstituted tetrazole-1,2,3-triazoles: an in silico assay. PEERJ PHYSICAL CHEMISTRY 2020. [DOI: 10.7717/peerj-pchem.10] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In regard to the actual public health global emergency and, based on the state of the art about the ways to inhibit the SARS-CoV-2 treating the COVID19, a family of 1,5-disubstituted tetrazole-1,2,3-triazoles, previously synthesized, have been evaluated through in silico assays against the main protease of the mentioned virus (CoV-2-MPro). The results show that three of these compounds present a more favorable interaction with the selected target than the co-crystallized molecule, which is a peptide-like derivative. It was also found that also hydrophobic interactions play a key role in the ligand-target molecular couplings, due to the higher hydrophobic surfaces into the active site. Finally, a pharmacophore model has been proposed based on the results below, and a family of 1,5-DT derivatives has been designed and tested with the same methods employed in this work. It was concluded that the compound with the isatin as a substituent (P8) present the higher ligand-target interaction, which makes this a strong drug candidate against COVID19, due can inhibit the CoV-2-MProprotein.
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Affiliation(s)
- Carlos J. Cortés-García
- Laboratorio de Diseño Molecular, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México
| | - Luis Chacón-García
- Laboratorio de Diseño Molecular, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México
| | - Jorge Emmanuel Mejía-Benavides
- Departamento de Enfermería y Obstetricia, Centro Interdisciplinario del Noreste (CINUG), Universidad de Guanajuato, Tierra Blanca, Guanajuato, México
| | - Erik Díaz-Cervantes
- Departamento de Alimentos, Centro Interdisciplinario del Noreste (CINUG), Universidad de Guanajuato, Tierra Blanca, Guanajuato, México
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10
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Mondal D, Kolev V, Warshel A. Combinatorial Approach for Exploring Conformational Space and Activation Barriers in Computer-Aided Enzyme Design. ACS Catal 2020; 10:6002-6012. [PMID: 34178420 PMCID: PMC8225234 DOI: 10.1021/acscatal.0c01206] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Computer-aided enzyme design is a field of great potential importance for biotechnological applications, medical advances, and a fundamental understanding of enzyme action. However, reaching a predictive ability in this direction is extremely challenging. It requires both the ability to predict quantitatively the activation barriers in cases where the structure and sequence are known and the ability to predict the effect of different mutations. In this work, we propose a protocol for predicting reasonable starting structures of mutants of proteins with known structures and for calculating the activation barriers of the generated mutants. Our approach also allows us to use the predicted structures of the generated mutant to predict structures and activation barriers for subsequent set of mutations. This protocol is used to examine the reliability of the in silico directed evolution of Kemp eliminase and haloalkane dehalogenase. We also used the results of single and double mutations as a base for predicting the effect of transition-state stabilization by multiple concurrent mutations. This strategy seems to be useful in creating an activity funnel that provides a qualitative ranking of the catalytic power of different mutants.
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Affiliation(s)
- Dibyendu Mondal
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Vesselin Kolev
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Arieh Warshel
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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11
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Cristobal JR, Reyes AC, Richard JP. The Organization of Active Site Side Chains of Glycerol-3-phosphate Dehydrogenase Promotes Efficient Enzyme Catalysis and Rescue of Variant Enzymes. Biochemistry 2020; 59:1582-1591. [PMID: 32250105 PMCID: PMC7207223 DOI: 10.1021/acs.biochem.0c00175] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
A comparison of the
values of kcat/Km for reduction of dihydroxyacetone phosphate
(DHAP) by NADH catalyzed by wild type and K120A/R269A variant glycerol-3-phosphate
dehydrogenase from human liver (hlGPDH) shows that
the transition state for enzyme-catalyzed hydride transfer is stabilized
by 12.0 kcal/mol by interactions with the cationic K120 and R269 side
chains. The transition state for the K120A/R269A variant-catalyzed
reduction of DHAP is stabilized by 1.0 and 3.8 kcal/mol for reactions
in the presence of 1.0 M EtNH3+ and guanidinium
cation (Gua+), respectively, and by 7.5 kcal/mol for reactions
in the presence of a mixture of each cation at 1.0 M, so that the
transition state stabilization by the ternary E·EtNH3+·Gua+ complex is 2.8 kcal/mol greater
than the sum of stabilization by the respective binary complexes.
This shows that there is cooperativity between the paired activators
in transition state stabilization. The effective molarities (EMs)
of ∼50 M determined for the K120A and R269A side chains are
≪106 M, the EM for entropically controlled reactions.
The unusually efficient rescue of the activity of hlGPDH-catalyzed reactions by the HPi/Gua+ pair
and by the Gua+/EtNH3+ activator
pair is due to stabilizing interactions between the protein and the
activator pieces that organize the K120 and R269 side chains at the
active site. This “preorganization” of side chains promotes
effective catalysis by hlGPDH and many other enzymes.
The role of the highly conserved network of side chains, which include
Q295, R269, N270, N205, T264, K204, D260, and K120, in catalysis is
discussed.
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Affiliation(s)
- Judith R Cristobal
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
| | - Archie C Reyes
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
| | - John P Richard
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
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12
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Cuesta SA, Mora JR, Zambrano CH, Torres FJ, Rincón L. Comparative study of the nucleophilic attack step in the proteases catalytic activity: A theoretical study. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1705412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Sebastián A. Cuesta
- Instituto de Simulación Computacional (ISM), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
- Departamento de Ingeniería Química – Grupo de Química Computacional y Teórica (QCT), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
| | - José R. Mora
- Instituto de Simulación Computacional (ISM), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
- Departamento de Ingeniería Química – Grupo de Química Computacional y Teórica (QCT), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
| | - Cesar H. Zambrano
- Instituto de Simulación Computacional (ISM), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
- Departamento de Ingeniería Química – Grupo de Química Computacional y Teórica (QCT), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
| | - F. Javier Torres
- Instituto de Simulación Computacional (ISM), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
- Departamento de Ingeniería Química – Grupo de Química Computacional y Teórica (QCT), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
| | - Luis Rincón
- Instituto de Simulación Computacional (ISM), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
- Departamento de Ingeniería Química – Grupo de Química Computacional y Teórica (QCT), Universidad San Francisco de Quito (USFQ), Quito, Ecuador
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13
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Jones WM, Davis AG, Wilson RH, Elliott KL, Sumner I. A conserved asparagine in a ubiquitin-conjugating enzyme positions the substrate for nucleophilic attack. J Comput Chem 2019; 40:1969-1977. [PMID: 31070815 DOI: 10.1002/jcc.25852] [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: 11/29/2018] [Revised: 02/26/2019] [Accepted: 04/14/2019] [Indexed: 01/30/2023]
Abstract
The mechanism used by the ubiquitin-conjugating enzyme, Ubc13, to catalyze ubiquitination is probed with three computational techniques: Born-Oppenheimer molecular dynamics, single point quantum mechanics/molecular mechanics energies, and classical molecular dynamics. These simulations support a long-held hypothesis and show that Ubc13-catalyzed ubiquitination uses a stepwise, nucleophilic attack mechanism. Furthermore, they show that the first step-the formation of a tetrahedral, zwitterionic intermediate-is rate limiting. However, these simulations contradict another popular hypothesis that supposes that the negative charge on the intermediate is stabilized by a highly conserved asparagine (Asn79 in Ubc13). Instead, calculated reaction profiles of the N79A mutant illustrate how charge stabilization actually increases the barrier to product formation. Finally, an alternate role for Asn79 is suggested by simulations of wild-type, N79A, N79D, and H77A Ubc13: it stabilizes the motion of the electrophile prior to the reaction, positioning it for nucleophilic attack. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Walker M Jones
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| | - Aaron G Davis
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| | - R Hunter Wilson
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| | - Katherine L Elliott
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| | - Isaiah Sumner
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
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14
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Martínez-Rodríguez S, Conejero-Muriel M, Gavira JA. A novel cysteine carbamoyl-switch is responsible for the inhibition of formamidase, a nitrilase superfamily member. Arch Biochem Biophys 2019; 662:151-159. [PMID: 30528776 DOI: 10.1016/j.abb.2018.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 11/28/2018] [Accepted: 12/04/2018] [Indexed: 11/25/2022]
Abstract
Formamidases (EC 3.5.1.49) and amidases (EC 3.5.1.4) are paralogous cysteine-dependent enzymes which catalyze the conversion of amide substrates to ammonia and the corresponding carboxylic acid. Both enzymes have been suggested as an alternative pathway for ammonia production during urea shortage. Urea was proved key in the transcriptional regulation of formamidases/amidases, connecting urea level to amide metabolism. In addition, different amidases have also been shown to be inhibited by urea, pointing to urea-regulation at the enzymatic level. Although amidases have been widely studied due to its biotechnological application in the hydrolysis of aliphatic amides, up to date, only two formamidases have been extensively characterized, belonging to Helicobacter pylori (HpyAmiF) and Bacillus cereus (BceAmiF). In this work, we report the first structure of an acyl-intermediate of BceAmiF. We also report the inhibition of BceAmiF by urea, together with mass spectrometry studies confirming the S-carbamoylation of BceAmiF after urea treatment. X-ray studies of urea-soaked BceAmiF crystals showed short- and long-range rearrangements affecting oligomerization interfaces. Since cysteine-based switches are known to occur in the regulation of different metabolic and signaling pathways, our results suggest a novel S-carbamoylation-switch for the regulation of BceAmiF. This finding could relate to previous observations of unexplained modifications in the catalytic cysteine of different nitrilase superfamily members and therefore extending this regulation mechanism to the whole nitrilase superfamily.
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Affiliation(s)
- Sergio Martínez-Rodríguez
- Departamento de Bioquímica y Biología Molecular III e Inmunología, Universidad de Granada (Campus de Melilla), 52071, Melilla, Spain; Laboratorio de Estudios Cristalográficos, CSIC-UGR, 18100, Granada, Spain.
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15
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Medina FE, Neves RPP, Ramos MJ, Fernandes PA. QM/MM Study of the Reaction Mechanism of the Dehydratase Domain from Mammalian Fatty Acid Synthase. ACS Catal 2018. [DOI: 10.1021/acscatal.8b02616] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fabiola E. Medina
- UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Rui P. P. Neves
- UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Maria J. Ramos
- UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Pedro A. Fernandes
- UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
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16
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Aboelnga MM, Hayward JJ, Gauld JW. Unraveling the Critical Role Played by Ado762'OH in the Post-Transfer Editing by Archaeal Threonyl-tRNA Synthetase. J Phys Chem B 2018; 122:1092-1101. [PMID: 29281289 DOI: 10.1021/acs.jpcb.7b10254] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Archaeal threonyl-tRNA synthetase (ThrRS) possesses an editing active site wherein tRNAThr that has been misaminoacylated with serine (i.e., Ser-tRNAThr) is hydrolytically cleaved to serine and tRNAThr. It has been suggested that the free ribose sugar hydroxyl of Ado76 of the tRNAThr (Ado762'OH) is the mechanistic base, promoting hydrolysis by orienting a nucleophilic water near the scissile Ser-tRNAThr ester bond. We have performed a computational study, involving molecular dynamics (MD) and hybrid ONIOM quantum mechanics/molecular mechanics (QM/MM) methods, considering all possible editing mechanisms to gain an understanding of the role played by Ado762'OH group. More specifically, a range of concerted or stepwise mechanisms involving four-, six-, or eight-membered transition structures (total of seven mechanisms) were considered. In addition, these seven mechanisms were fully optimized using three different DFT functionals, namely, B3LYP, M06-2X, and M06-HF. The M06-HF functional gave the most feasible energy barriers followed by the M06-2X functional. The most favorable mechanism proceeds stepwise through two six-membered ring transition states in which the Ado762'OH group participates, overall, as a shuttle for the proton transfer from the nucleophilic H2O to the bridging oxygen (Ado763'O) of the substrate. More specifically, in the first step, which has a barrier of 25.9 kcal/mol, the Ado762'-OH group accepts a proton from the attacking nucleophilic water while concomitantly transferring its proton onto the substrates C-Ocarb center. Then, in the second step, which also proceeds with a barrier of 25.9 kcal/mol, the Ado762'-OH group transfers its proton on the adjacent Ado763'-oxygen, cleaving the scissile Ccarb-O3'Ado76 bond, while concomitantly accepting a proton from the previously formed C-OcarbH group.
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Affiliation(s)
- Mohamed M Aboelnga
- Department of Chemistry and Biochemistry, University of Windsor , Windsor, Ontario N9B 3P4, Canada.,Department of Chemistry, Faculty of Science, Damietta University , New Damietta, Damietta Governorate 34511, Egypt
| | - John J Hayward
- Department of Chemistry and Biochemistry, University of Windsor , Windsor, Ontario N9B 3P4, Canada
| | - James W Gauld
- Department of Chemistry and Biochemistry, University of Windsor , Windsor, Ontario N9B 3P4, Canada
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17
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Hung PY, Chen YH, Huang KY, Yu CC, Horng JC. Design of Polyproline-Based Catalysts for Ester Hydrolysis. ACS OMEGA 2017; 2:5574-5581. [PMID: 31457823 PMCID: PMC6644415 DOI: 10.1021/acsomega.7b00928] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/24/2017] [Indexed: 05/21/2023]
Abstract
A number of simple oligopeptides have been recently developed as minimalistic catalysts for mimicking the activity and selectivity of natural proteases. Although the arrangement of amino acid residues in natural enzymes provides a strategy for designing artificial enzymes, creating catalysts with efficient binding and catalytic activity is still challenging. In this study, we used the polyproline scaffold and designed a series of 13-residue peptides with a catalytic dyad or triad incorporated to serve as artificial enzymes. Their catalytic efficiency on ester hydrolysis was evaluated by ultraviolet-visible spectroscopy using the p-nitrophenyl acetate assay, and their secondary structures were also characterized by circular dichroism spectroscopy. The results indicate that a well-formed polyproline II structure may result in a much higher catalytic efficiency. This is the first report to show that a functional dyad or triad engineered into a polyproline helix framework can enhance the catalytic activity on ester hydrolysis. Our study has also revealed the necessity of maintaining an ordered structure and a well-organized catalytic site for effective biocatalysts.
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Affiliation(s)
- Pei-Yu Hung
- Department
of Chemistry and Frontier Research Center on Fundamental and
Applied Science of Matters, National Tsing
Hua University, 101 Sec. 2 Kuang-Fu Rd., Hsinchu, Taiwan 30013, ROC
| | - Yu-Han Chen
- Department
of Chemistry and Frontier Research Center on Fundamental and
Applied Science of Matters, National Tsing
Hua University, 101 Sec. 2 Kuang-Fu Rd., Hsinchu, Taiwan 30013, ROC
| | - Kuei-Yen Huang
- Department
of Chemistry and Frontier Research Center on Fundamental and
Applied Science of Matters, National Tsing
Hua University, 101 Sec. 2 Kuang-Fu Rd., Hsinchu, Taiwan 30013, ROC
| | - Chi-Ching Yu
- Department
of Chemistry and Frontier Research Center on Fundamental and
Applied Science of Matters, National Tsing
Hua University, 101 Sec. 2 Kuang-Fu Rd., Hsinchu, Taiwan 30013, ROC
| | - Jia-Cherng Horng
- Department
of Chemistry and Frontier Research Center on Fundamental and
Applied Science of Matters, National Tsing
Hua University, 101 Sec. 2 Kuang-Fu Rd., Hsinchu, Taiwan 30013, ROC
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18
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Tuo W, Leleu-Chavain N, Spencer J, Sansook S, Millet R, Chavatte P. Therapeutic Potential of Fatty Acid Amide Hydrolase, Monoacylglycerol Lipase, and N-Acylethanolamine Acid Amidase Inhibitors. J Med Chem 2016; 60:4-46. [DOI: 10.1021/acs.jmedchem.6b00538] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Wei Tuo
- Université de Lille, Inserm, CHU Lille, U995,
LIRIC, Lille Inflammation Research International Center, F-59000 Lille, France
| | - Natascha Leleu-Chavain
- Université de Lille, Inserm, CHU Lille, U995,
LIRIC, Lille Inflammation Research International Center, F-59000 Lille, France
| | - John Spencer
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, U.K
| | - Supojjanee Sansook
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, U.K
| | - Régis Millet
- Université de Lille, Inserm, CHU Lille, U995,
LIRIC, Lille Inflammation Research International Center, F-59000 Lille, France
| | - Philippe Chavatte
- Université de Lille, Inserm, CHU Lille, U995,
LIRIC, Lille Inflammation Research International Center, F-59000 Lille, France
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19
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Murphy JR, Mullins EA, Kappock TJ. Functional Dissection of the Bipartite Active Site of the Class I Coenzyme A (CoA)-Transferase Succinyl-CoA:Acetate CoA-Transferase. Front Chem 2016; 4:23. [PMID: 27242998 PMCID: PMC4876117 DOI: 10.3389/fchem.2016.00023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 04/28/2016] [Indexed: 12/04/2022] Open
Abstract
Coenzyme A (CoA)-transferases catalyze the reversible transfer of CoA from acyl-CoA thioesters to free carboxylates. Class I CoA-transferases produce acylglutamyl anhydride intermediates that undergo attack by CoA thiolate on either the internal or external carbonyl carbon atoms, forming distinct tetrahedral intermediates <3 Å apart. In this study, crystal structures of succinyl-CoA:acetate CoA-transferase (AarC) from Acetobacter aceti are used to examine how the Asn347 carboxamide stabilizes the internal oxyanion intermediate. A structure of the active mutant AarC-N347A bound to CoA revealed both solvent replacement of the missing contact and displacement of the adjacent Glu294, indicating that Asn347 both polarizes and orients the essential glutamate. AarC was crystallized with the nonhydrolyzable acetyl-CoA (AcCoA) analog dethiaacetyl-CoA (1a) in an attempt to trap a closed enzyme complex containing a stable analog of the external oxyanion intermediate. One active site contained an acetylglutamyl anhydride adduct and truncated 1a, an unexpected result hinting at an unprecedented cleavage of the ketone moiety in 1a. Solution studies confirmed that 1a decomposition is accompanied by production of near-stoichiometric acetate, in a process that seems to depend on microbial contamination but not AarC. A crystal structure of AarC bound to the postulated 1a truncation product (2a) showed complete closure of one active site per dimer but no acetylglutamyl anhydride, even with acetate added. These findings suggest that an activated acetyl donor forms during 1a decomposition; a working hypothesis involving ketone oxidation is offered. The ability of 2a to induce full active site closure furthermore suggests that it subverts a system used to impede inappropriate active site closure on unacylated CoA.
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Affiliation(s)
- Jesse R Murphy
- Department of Biochemistry, Purdue University West Lafayette, IN, USA
| | - Elwood A Mullins
- Department of Biochemistry, Purdue University West Lafayette, IN, USA
| | - T Joseph Kappock
- Department of Biochemistry, Purdue University West Lafayette, IN, USA
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20
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Onwukwe GU, Koski MK, Pihko P, Schmitz W, Wierenga RK. Structures of yeast peroxisomal Δ(3),Δ(2)-enoyl-CoA isomerase complexed with acyl-CoA substrate analogues: the importance of hydrogen-bond networks for the reactivity of the catalytic base and the oxyanion hole. ACTA ACUST UNITED AC 2015; 71:2178-91. [PMID: 26527136 DOI: 10.1107/s139900471501559x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 08/19/2015] [Indexed: 11/10/2022]
Abstract
Δ(3),Δ(2)-Enoyl-CoA isomerases (ECIs) catalyze the shift of a double bond from 3Z- or 3E-enoyl-CoA to 2E-enoyl-CoA. ECIs are members of the crotonase superfamily. The crotonase framework is used by many enzymes to catalyze a wide range of reactions on acyl-CoA thioesters. The thioester O atom is bound in a conserved oxyanion hole. Here, the mode of binding of acyl-CoA substrate analogues to peroxisomal Saccharomyces cerevisiae ECI (ScECI2) is described. The best defined part of the bound acyl-CoA molecules is the 3',5'-diphosphate-adenosine moiety, which interacts with residues of loop 1 and loop 2, whereas the pantetheine part is the least well defined. The catalytic base, Glu158, is hydrogen-bonded to the Asn101 side chain and is further hydrogen-bonded to the side chain of Arg100 in the apo structure. Arg100 is completely buried in the apo structure and a conformational change of the Arg100 side chain appears to be important for substrate binding and catalysis. The oxyanion hole is formed by the NH groups of Ala70 (loop 2) and Leu126 (helix 3). The O atoms of the corresponding peptide units, Gly69 O and Gly125 O, are both part of extensive hydrogen-bond networks. These hydrogen-bond networks are a conserved feature of the crotonase oxyanion hole and their importance for catalysis is discussed.
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Affiliation(s)
- Goodluck U Onwukwe
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - M Kristian Koski
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Petri Pihko
- Department of Chemistry, University of Jyväskylä, Jyväskylä, Finland
| | - Werner Schmitz
- Department of Biochemistry and Molecular Biology, University of Würzburg, Biozentrum, Am Hubland, 97074 Würzburg, Germany
| | - Rik K Wierenga
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
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21
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London N, Farelli JD, Brown SD, Liu C, Huang H, Korczynska M, Al-Obaidi NF, Babbitt PC, Almo SC, Allen KN, Shoichet BK. Covalent docking predicts substrates for haloalkanoate dehalogenase superfamily phosphatases. Biochemistry 2015; 54:528-37. [PMID: 25513739 PMCID: PMC4303301 DOI: 10.1021/bi501140k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
![]()
Enzyme function prediction remains
an important open problem. Though
structure-based modeling, such as metabolite docking, can identify
substrates of some enzymes, it is ill-suited to reactions that progress
through a covalent intermediate. Here we investigated the ability
of covalent docking to identify substrates that pass through such
a covalent intermediate, focusing particularly on the haloalkanoate
dehalogenase superfamily. In retrospective assessments, covalent docking
recapitulated substrate binding modes of known cocrystal structures
and identified experimental substrates from a set of putative phosphorylated
metabolites. In comparison, noncovalent docking of high-energy intermediates
yielded nonproductive poses. In prospective predictions against seven
enzymes, a substrate was identified for five. For one of those cases,
a covalent docking prediction, confirmed by empirical screening, and
combined with genomic context analysis, suggested the identity of
the enzyme that catalyzes the orphan phosphatase reaction in the riboflavin
biosynthetic pathway of Bacteroides.
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Affiliation(s)
- Nir London
- Department of Pharmaceutical Chemistry, and §Department of Bioengineering and Therapeutic Sciences, University of California San Francisco , San Francisco, California 94158, United States
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22
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Kiema TR, Harijan RK, Strozyk M, Fukao T, Alexson SEH, Wierenga RK. The crystal structure of human mitochondrial 3-ketoacyl-CoA thiolase (T1): insight into the reaction mechanism of its thiolase and thioesterase activities. ACTA ACUST UNITED AC 2014; 70:3212-25. [PMID: 25478839 DOI: 10.1107/s1399004714023827] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 10/28/2014] [Indexed: 11/10/2022]
Abstract
Crystal structures of human mitochondrial 3-ketoacyl-CoA thiolase (hT1) in the apo form and in complex with CoA have been determined at 2.0 Å resolution. The structures confirm the tetrameric quaternary structure of this degradative thiolase. The active site is surprisingly similar to the active site of the Zoogloea ramigera biosynthetic tetrameric thiolase (PDB entries 1dm3 and 1m1o) and different from the active site of the peroxisomal dimeric degradative thiolase (PDB entries 1afw and 2iik). A cavity analysis suggests a mode of binding for the fatty-acyl tail in a tunnel lined by the Nβ2-Nα2 loop of the adjacent subunit and the Lα1 helix of the loop domain. Soaking of the apo hT1 crystals with octanoyl-CoA resulted in a crystal structure in complex with CoA owing to the intrinsic acyl-CoA thioesterase activity of hT1. Solution studies confirm that hT1 has low acyl-CoA thioesterase activity for fatty acyl-CoA substrates. The fastest rate is observed for the hydrolysis of butyryl-CoA. It is also shown that T1 has significant biosynthetic thiolase activity, which is predicted to be of physiological importance.
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Affiliation(s)
- Tiila Riikka Kiema
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland
| | - Rajesh K Harijan
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland
| | - Malgorzata Strozyk
- Karolinska Institutet, Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan
| | - Stefan E H Alexson
- Karolinska Institutet, Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Rik K Wierenga
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland
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23
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Palermo G, Campomanes P, Cavalli A, Rothlisberger U, De Vivo M. Anandamide Hydrolysis in FAAH Reveals a Dual Strategy for Efficient Enzyme-Assisted Amide Bond Cleavage via Nitrogen Inversion. J Phys Chem B 2014; 119:789-801. [DOI: 10.1021/jp5052276] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Giulia Palermo
- Department
of Drug Discovery and Development, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Pablo Campomanes
- Laboratory
of Computational Chemistry and Biochemistry, Institute of Chemical
Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne
(EPFL), CH-1015 Lausanne, Switzerland
| | - Andrea Cavalli
- Department
of Drug Discovery and Development, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
- Department
of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro
6, I-40126 Bologna, Italy
| | - Ursula Rothlisberger
- Laboratory
of Computational Chemistry and Biochemistry, Institute of Chemical
Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne
(EPFL), CH-1015 Lausanne, Switzerland
| | - Marco De Vivo
- Department
of Drug Discovery and Development, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
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24
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Richard JP, Amyes TL, Goryanova B, Zhai X. Enzyme architecture: on the importance of being in a protein cage. Curr Opin Chem Biol 2014; 21:1-10. [PMID: 24699188 DOI: 10.1016/j.cbpa.2014.03.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 03/01/2014] [Indexed: 11/30/2022]
Abstract
Substrate binding occludes water from the active sites of many enzymes. There is a correlation between the burden to enzymatic catalysis of deprotonation of carbon acids and the substrate immobilization at solvent-occluded active sites for ketosteroid isomerase (KSI--small burden, substrate pKa=13), triosephosphate isomerase (TIM, substrate pKa≈18) and diaminopimelate epimerase (DAP epimerase, large burden, substrate pKa≈29) catalyzed reaction. KSI binds substrates at a surface cleft, TIM binds substrate at an exposed 'cage' formed by closure of flexible loops; and, DAP epimerase binds substrate in a tight cage formed by an 'oyster-like' clamping motion of protein domains. Directed evolution of a solvent-occluded active site at a designed protein catalyst of the Kemp elimination reaction is discussed.
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Affiliation(s)
- John P Richard
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, NY 14260-3000, USA.
| | - Tina L Amyes
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, NY 14260-3000, USA
| | - Bogdana Goryanova
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, NY 14260-3000, USA
| | - Xiang Zhai
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, NY 14260-3000, USA
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25
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Metrano AJ, Miller SJ. Peptide-catalyzed conversion of racemic oxazol-5(4H)-ones into enantiomerically enriched α-amino acid derivatives. J Org Chem 2014; 79:1542-54. [PMID: 24517453 DOI: 10.1021/jo402828f] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We report the development and optimization of a tetrapeptide that catalyzes the methanolytic dynamic kinetic resolution of oxazol-5(4H)-ones (azlactones) with high levels of enantioinduction. Oxazolones possessing benzylic-type substituents were found to perform better than others, providing methyl ester products in 88:12 to 98:2 er. The mechanism of this peptide-catalyzed process was investigated through truncation studies and competition experiments. High-field NOESY analysis was performed to elucidate the solution-phase structure of the peptide, and we present a plausible model for catalysis.
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Affiliation(s)
- Anthony J Metrano
- Department of Chemistry, Yale University , New Haven, Connecticut 06520-8107, United States
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26
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Fujihashi M, Ishida T, Kuroda S, Kotra LP, Pai EF, Miki K. Substrate distortion contributes to the catalysis of orotidine 5'-monophosphate decarboxylase. J Am Chem Soc 2013; 135:17432-43. [PMID: 24151964 PMCID: PMC3949427 DOI: 10.1021/ja408197k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Orotidine 5'-monophosphate decarboxylase (ODCase) accelerates the decarboxylation of orotidine 5'-monophosphate (OMP) to uridine 5'-monophosphate (UMP) by 17 orders of magnitude. Eight new crystal structures with ligand analogues combined with computational analyses of the enzyme's short-lived intermediates and the intrinsic electronic energies to distort the substrate and other ligands improve our understanding of the still controversially discussed reaction mechanism. In their respective complexes, 6-methyl-UMP displays significant distortion of its methyl substituent bond, 6-amino-UMP shows the competition between the K72 and C6 substituents for a position close to D70, and the methyl and ethyl esters of OMP both induce rotation of the carboxylate group substituent out of the plane of the pyrimidine ring. Molecular dynamics and quantum mechanics/molecular mechanics computations of the enzyme-substrate complex also show the bond between the carboxylate group and the pyrimidine ring to be distorted, with the distortion contributing a 10-15% decrease of the ΔΔG(⧧) value. These results are consistent with ODCase using both substrate distortion and transition-state stabilization, primarily exerted by K72, in its catalysis of the OMP decarboxylation reaction.
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Affiliation(s)
- Masahiro Fujihashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Toyokazu Ishida
- Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba 305-8568, Japan
| | - Shingo Kuroda
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Lakshmi P. Kotra
- Center for Molecular Design and Preformulations and Division of Cell & Molecular Biology, Toronto General Research Institute/University Health Network, Toronto, ON, Canada M5G 1L7
- Departments of Pharmaceutical Sciences and Chemistry, McLaughlin Center for Molecular Medicine, University of Toronto, Canada M5S 3M2
| | - Emil F. Pai
- Center for Molecular Design and Preformulations and Division of Cell & Molecular Biology, Toronto General Research Institute/University Health Network, Toronto, ON, Canada M5G 1L7
- The Campbell Family Cancer Research Institute, Ontario Cancer Institute/University Health Network & Departments of Biochemistry, Medical Biophysics, and Molecular Genetics, University of Toronto, Toronto, ON, Canada M5G 1L7
| | - Kunio Miki
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
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27
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Syrén PO. The solution of nitrogen inversion in amidases. FEBS J 2013; 280:3069-83. [DOI: 10.1111/febs.12241] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 03/06/2013] [Accepted: 03/08/2013] [Indexed: 01/06/2023]
Affiliation(s)
- Per-Olof Syrén
- Institute of Technical Biochemistry; University of Stuttgart; Germany
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28
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Yang H, Wong MW. Oxyanion Hole Stabilization by C–H···O Interaction in a Transition State—A Three-Point Interaction Model for Cinchona Alkaloid-Catalyzed Asymmetric Methanolysis of meso-Cyclic Anhydrides. J Am Chem Soc 2013; 135:5808-18. [DOI: 10.1021/ja4005893] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hui Yang
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Ming Wah Wong
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
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29
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Abstract
Linus Pauling proposed that the large rate accelerations for enzymes are caused by the high specificity of the protein catalyst for binding the reaction transition state. The observation that stable analogues of the transition states for enzymatic reactions often act as tight-binding inhibitors provided early support for this simple and elegant proposal. We review experimental results that support the proposal that Pauling's model provides a satisfactory explanation for the rate accelerations for many heterolytic enzymatic reactions through high-energy reaction intermediates, such as proton transfer and decarboxylation. Specificity in transition state binding is obtained when the total intrinsic binding energy of the substrate is significantly larger than the binding energy observed at the Michaelis complex. The results of recent studies that aimed to characterize the specificity in binding of the enolate oxygen at the transition state for the 1,3-isomerization reaction catalyzed by ketosteroid isomerase are reviewed. Interactions between pig heart succinyl-coenzyme A:3-oxoacid coenzyme A transferase (SCOT) and the nonreacting portions of coenzyme A (CoA) are responsible for a rate increase of 3 × 10(12)-fold, which is close to the estimated total 5 × 10(13)-fold enzymatic rate acceleration. Studies that partition the interactions between SCOT and CoA into their contributing parts are reviewed. Interactions of the protein with the substrate phosphodianion group provide an ~12 kcal/mol stabilization of the transition state for the reactions catalyzed by triosephosphate isomerase, orotidine 5'-monophosphate decarboxylase, and α-glycerol phosphate dehydrogenase. The interactions of these enzymes with the substrate piece phosphite dianion provide a 6-8 kcal/mol stabilization of the transition state for reaction of the appropriate truncated substrate. Enzyme activation by phosphite dianion reflects the higher dianion affinity for binding to the enzyme-transition state complex compared with that of the free enzyme. Evidence is presented that supports a model in which the binding energy of the phosphite dianion piece, or the phosphodianion group of the whole substrate, is utilized to drive an enzyme conformational change from an inactive open form E(O) to an active closed form E(C), by closure of a phosphodianion gripper loop. Members of the enolase and haloalkanoic acid dehalogenase superfamilies use variable capping domains to interact with nonreacting portions of the substrate and sequester the substrate from interaction with bulk solvent. Interactions of this capping domain with the phenyl group of mandelate have been shown to activate mandelate racemase for catalysis of deprotonation of α-carbonyl carbon. We propose that an important function of these capping domains is to utilize the binding interactions with nonreacting portions of the substrate to activate the enzyme for catalysis.
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Affiliation(s)
- Tina L. Amyes
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, New York 14260-3000
| | - John P. Richard
- To whom correspondence should be addressed: Tel: (716) 645 4232; Fax: (716) 645 6963;
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30
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Fujihashi M, Mito K, Pai EF, Miki K. Atomic resolution structure of the orotidine 5'-monophosphate decarboxylase product complex combined with surface plasmon resonance analysis: implications for the catalytic mechanism. J Biol Chem 2013; 288:9011-6. [PMID: 23395822 DOI: 10.1074/jbc.m112.427252] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Orotidine 5'-monophosphate decarboxylase (ODCase) accelerates the decarboxylation of its substrate by 17 orders of magnitude. One argument brought forward against steric/electrostatic repulsion causing substrate distortion at the carboxylate substituent as part of the catalysis has been the weak binding affinity of the decarboxylated product (UMP). The crystal structure of the UMP complex of ODCase at atomic resolution (1.03 Å) shows steric competition between the product UMP and the side chain of a catalytic lysine residue. Surface plasmon resonance analysis indicates that UMP binds 5 orders of magnitude more tightly to a mutant in which the interfering side chain has been removed than to wild-type ODCase. These results explain the low affinity of UMP and counter a seemingly very strong argument against a contribution of substrate distortion to the catalytic reaction mechanism of ODCase.
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Affiliation(s)
- Masahiro Fujihashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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31
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Layfield JP, Hammes-Schiffer S. Calculation of vibrational shifts of nitrile probes in the active site of ketosteroid isomerase upon ligand binding. J Am Chem Soc 2012; 135:717-25. [PMID: 23210919 DOI: 10.1021/ja3084384] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The vibrational Stark effect provides insight into the roles of hydrogen bonding, electrostatics, and conformational motions in enzyme catalysis. In a recent application of this approach to the enzyme ketosteroid isomerase (KSI), thiocyanate probes were introduced in site-specific positions throughout the active site. This paper implements a quantum mechanical/molecular mechanical (QM/MM) approach for calculating the vibrational shifts of nitrile (CN) probes in proteins. This methodology is shown to reproduce the experimentally measured vibrational shifts upon binding of the intermediate analogue equilinen to KSI for two different nitrile probe positions. Analysis of the molecular dynamics simulations provides atomistic insight into the roles that key residues play in determining the electrostatic environment and hydrogen-bonding interactions experienced by the nitrile probe. For the M116C-CN probe, equilinen binding reorients an active-site water molecule that is directly hydrogen-bonded to the nitrile probe, resulting in a more linear C≡N--H angle and increasing the CN frequency upon binding. For the F86C-CN probe, equilinen binding orients the Asp103 residue, decreasing the hydrogen-bonding distance between the Asp103 backbone and the nitrile probe and slightly increasing the CN frequency. This QM/MM methodology is applicable to a wide range of biological systems and has the potential to assist in the elucidation of the fundamental principles underlying enzyme catalysis.
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Affiliation(s)
- Joshua P Layfield
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
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32
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Mullins EA, Kappock TJ. Crystal structures of Acetobacter aceti succinyl-coenzyme A (CoA):acetate CoA-transferase reveal specificity determinants and illustrate the mechanism used by class I CoA-transferases. Biochemistry 2012; 51:8422-34. [PMID: 23030530 DOI: 10.1021/bi300957f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Coenzyme A (CoA)-transferases catalyze transthioesterification reactions involving acyl-CoA substrates, using an active-site carboxylate to form covalent acyl anhydride and CoA thioester adducts. Mechanistic studies of class I CoA-transferases suggested that acyl-CoA binding energy is used to accelerate rate-limiting acyl transfers by compressing the substrate thioester tightly against the catalytic glutamate [White, H., and Jencks, W. P. (1976) J. Biol. Chem. 251, 1688-1699]. The class I CoA-transferase succinyl-CoA:acetate CoA-transferase is an acetic acid resistance factor (AarC) with a role in a variant citric acid cycle in Acetobacter aceti. In an effort to identify residues involved in substrate recognition, X-ray crystal structures of a C-terminally His(6)-tagged form (AarCH6) were determined for several wild-type and mutant complexes, including freeze-trapped acetylglutamyl anhydride and glutamyl-CoA thioester adducts. The latter shows the acetate product bound to an auxiliary site that is required for efficient carboxylate substrate recognition. A mutant in which the catalytic glutamate was changed to an alanine crystallized in a closed complex containing dethiaacetyl-CoA, which adopts an unusual curled conformation. A model of the acetyl-CoA Michaelis complex demonstrates the compression anticipated four decades ago by Jencks and reveals that the nucleophilic glutamate is held at a near-ideal angle for attack as the thioester oxygen is forced into an oxyanion hole composed of Gly388 NH and CoA N2″. CoA is nearly immobile along its entire length during all stages of the enzyme reaction. Spatial and sequence conservation of key residues indicates that this mechanism is general among class I CoA-transferases.
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Affiliation(s)
- Elwood A Mullins
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907-2063, USA
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33
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Richter F, Blomberg R, Khare SD, Kiss G, Kuzin AP, Smith AJT, Gallaher J, Pianowski Z, Helgeson RC, Grjasnow A, Xiao R, Seetharaman J, Su M, Vorobiev S, Lew S, Forouhar F, Kornhaber GJ, Hunt JF, Montelione GT, Tong L, Houk KN, Hilvert D, Baker D. Computational design of catalytic dyads and oxyanion holes for ester hydrolysis. J Am Chem Soc 2012; 134:16197-206. [PMID: 22871159 DOI: 10.1021/ja3037367] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nucleophilic catalysis is a general strategy for accelerating ester and amide hydrolysis. In natural active sites, nucleophilic elements such as catalytic dyads and triads are usually paired with oxyanion holes for substrate activation, but it is difficult to parse out the independent contributions of these elements or to understand how they emerged in the course of evolution. Here we explore the minimal requirements for esterase activity by computationally designing artificial catalysts using catalytic dyads and oxyanion holes. We found much higher success rates using designed oxyanion holes formed by backbone NH groups rather than by side chains or bridging water molecules and obtained four active designs in different scaffolds by combining this motif with a Cys-His dyad. Following active site optimization, the most active of the variants exhibited a catalytic efficiency (k(cat)/K(M)) of 400 M(-1) s(-1) for the cleavage of a p-nitrophenyl ester. Kinetic experiments indicate that the active site cysteines are rapidly acylated as programmed by design, but the subsequent slow hydrolysis of the acyl-enzyme intermediate limits overall catalytic efficiency. Moreover, the Cys-His dyads are not properly formed in crystal structures of the designed enzymes. These results highlight the challenges that computational design must overcome to achieve high levels of activity.
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Affiliation(s)
- Florian Richter
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
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34
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Hou QQ, Wang JH, Gao J, Liu YJ, Liu CB. QM/MM studies on the catalytic mechanism of phenylethanolamine N-methyltransferase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:533-41. [PMID: 22326747 DOI: 10.1016/j.bbapap.2012.01.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 01/05/2012] [Accepted: 01/26/2012] [Indexed: 02/06/2023]
Abstract
Epinephrine is a naturally occurring adrenomedullary hormone that transduces environmental stressors into cardiovascular actions. As the only route in the catecholamine biosynthetic pathway, Phenylethanolamine N-methyltransferase (PNMT) catalyzes the synthesis of epinephrine. To elucidate the detailed mechanism of enzymatic catalysis of PNMT, combined quantum-mechanical/molecular-mechanical (QM/MM) calculations were performed. The calculation results reveal that this catalysis contains three elementary steps: the deprotonation of protonated norepinphrine, the methyl transferring step and deprotonation of the methylated norepinphrine. The methyl transferring step was proved to be the rate-determining step undergoing a SN2 mechanism with an energy barrier of 16.4kcal/mol. During the whole catalysis, two glutamic acids Glu185 and Glu219 were proved to be loaded with different effects according to the calculations results of the mutants. These calculation results can be used to explain the experimental observations and make a good complementarity for the previous QM study.
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Affiliation(s)
- Q Q Hou
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong, China
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35
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QM/MM study of the mechanism of enzymatic limonene 1,2-epoxide hydrolysis. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:263-8. [DOI: 10.1016/j.bbapap.2011.08.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 08/29/2011] [Accepted: 08/29/2011] [Indexed: 11/22/2022]
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36
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Simón L, Goodman JM. Hydrogen-bond stabilization in oxyanion holes: grand jeté to three dimensions. Org Biomol Chem 2012; 10:1905-13. [PMID: 22273994 DOI: 10.1039/c2ob06717j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We recently reported crystallographic evidence that the hydrogen bonds which can stabilize oxygen-centered negative charge within enzyme oxyanion holes are rarely found in the place they should be expected on the basis of the analysis of small-molecule crystal structures. We investigated this phenomenon using calculations on simplified active site models. A recent paper suggested that several aspects of the analysis required further exploration. In this paper we: (i) review the results of our crystallographic study; (ii) report molecular dynamics studies which investigate the effect of protein movement; (iii) report ONIOM calculations which trace the reaction coordinate for an oxyanion hole reaction in the presence of a complete enzyme active site. These results show that the limitations of gas phase calculations on simplified models do not invalidate our comparison of competing active site geometries. These new results reaffirm the conclusion that oxyanion holes are not usually stabilized by planar arrangements of H-bonds, and that this sub-optimal transition state stabilization leads to better overall catalysis.
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Affiliation(s)
- Luis Simón
- Facultad de Ciencias Químicas, Universidad de Salamanca, Plaza de los Caídos 1-5, Salamanca, E37004, Spain.
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37
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Iiams V, Desai BJ, Fedorov AA, Fedorov EV, Almo SC, Gerlt JA. Mechanism of the orotidine 5'-monophosphate decarboxylase-catalyzed reaction: importance of residues in the orotate binding site. Biochemistry 2011; 50:8497-507. [PMID: 21870810 PMCID: PMC3199138 DOI: 10.1021/bi2012355] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The reaction catalyzed by orotidine 5'-monophosphate decarboxylase (OMPDC) is accompanied by exceptional values for rate enhancement (k(cat)/k(non) = 7.1 × 10(16)) and catalytic proficiency [(k(cat)/K(M))/k(non) = 4.8 × 10(22) M(-1)]. Although a stabilized vinyl carbanion/carbene intermediate is located on the reaction coordinate, the structural strategies by which the reduction in the activation energy barrier is realized remain incompletely understood. This laboratory recently reported that "substrate destabilization" by Asp 70 in the OMPDC from Methanothermobacter thermoautotrophicus (MtOMPDC) lowers the activation energy barrier by ∼5 kcal/mol (contributing ~2.7 × 10(3) to the rate enhancement) [Chan, K. K., Wood, B. M., Fedorov, A. A., Fedorov, E. V., Imker, H. J., Amyes, T. L., Richard, J. P., Almo, S. C., and Gerlt, J. A. (2009) Biochemistry 48, 5518-5531]. We now report that substitutions of hydrophobic residues in a pocket proximal to the carboxylate group of the substrate (Ile 96, Leu 123, and Val 155) with neutral hydrophilic residues decrease the value of k(cat) by as much as 400-fold but have a minimal effect on the value of k(ex) for exchange of H6 of the FUMP product analogue with solvent deuterium; we hypothesize that this pocket destabilizes the substrate by preventing hydration of the substrate carboxylate group. We also report that substitutions of Ser 127 that is proximal to O4 of the orotate ring decrease the value of k(cat)/K(M), with the S127P substitution that eliminates hydrogen bonding interactions with O4 producing a 2.5 × 10(6)-fold reduction; this effect is consistent with delocalization of the negative charge of the carbanionic intermediate on O4 that produces an anionic carbene intermediate and thereby provides a structural strategy for stabilization of the intermediate. These observations provide additional information about the identities of the active site residues that contribute to the rate enhancement and, therefore, insights into the structural strategies for catalysis.
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Affiliation(s)
- Vanessa Iiams
- Departments of Biochemistry and Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL
| | - Bijoy J. Desai
- Departments of Biochemistry and Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL
| | - Alexander A. Fedorov
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Elena V. Fedorov
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Steven C. Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
| | - John A. Gerlt
- Departments of Biochemistry and Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL,To whom correspondence should be addressed: J.A.G.: Institute for Genomic Biology, University of Illinois, 1206 West Gregory Drive, Urbana, IL 61801. Phone: (217) 244-7414. Fax: (217) 333-0508.
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38
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Garrec J, Sautet P, Fleurat-Lessard P. Understanding the HIV-1 Protease Reactivity with DFT: What Do We Gain from Recent Functionals? J Phys Chem B 2011; 115:8545-58. [DOI: 10.1021/jp200565w] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- J. Garrec
- Université de Lyon,CNRS, École Normale Supérieure de Lyon, Laboratoire de Chimie, 46 alléed’Italie, F-69364 Lyon Cedex 07
| | - P. Sautet
- Université de Lyon,CNRS, École Normale Supérieure de Lyon, Laboratoire de Chimie, 46 alléed’Italie, F-69364 Lyon Cedex 07
| | - P. Fleurat-Lessard
- Université de Lyon,CNRS, École Normale Supérieure de Lyon, Laboratoire de Chimie, 46 alléed’Italie, F-69364 Lyon Cedex 07
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39
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Pápai I, Hamza A, Pihko PM, Wierenga RK. Stereoelectronic Requirements for Optimal Hydrogen-Bond-Catalyzed Enolization. Chemistry 2011; 17:2859-66. [DOI: 10.1002/chem.201002943] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Indexed: 11/07/2022]
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