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Odoemelam CS, Percival B, Wallis H, Chang MW, Ahmad Z, Scholey D, Burton E, Williams IH, Kamerlin CL, Wilson PB. G-Protein coupled receptors: structure and function in drug discovery. RSC Adv 2020; 10:36337-36348. [PMID: 35517958 PMCID: PMC9057076 DOI: 10.1039/d0ra08003a] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
The G-protein coupled receptors (GPCRs) superfamily comprise similar proteins arranged into families or classes thus making it one of the largest in the mammalian genome. GPCRs take part in many vital physiological functions making them targets for numerous novel drugs. GPCRs share some distinctive features, such as the seven transmembrane domains, they also differ in the number of conserved residues in their transmembrane domain. Here we provide an introductory and accessible review detailing the computational advances in GPCR pharmacology and drug discovery. An overview is provided on family A-C GPCRs; their structural differences, GPCR signalling, allosteric binding and cooperativity. The dielectric constant (relative permittivity) of proteins is also discussed in the context of site-specific environmental effects.
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Affiliation(s)
| | - Benita Percival
- Nottingham Trent University 50 Shakespeare St Nottingham NG1 4FQ UK
| | - Helen Wallis
- Nottingham Trent University 50 Shakespeare St Nottingham NG1 4FQ UK
| | - Ming-Wei Chang
- Nanotechnology and Integrated Bioengineering Centre, University of Ulster Jordanstown Campus Newtownabbey BT37 0QB Northern Ireland UK
| | - Zeeshan Ahmad
- De Montfort University The Gateway Leicester LE1 9BH UK
| | - Dawn Scholey
- Nottingham Trent University 50 Shakespeare St Nottingham NG1 4FQ UK
| | - Emily Burton
- Nottingham Trent University 50 Shakespeare St Nottingham NG1 4FQ UK
| | - Ian H Williams
- Department of Chemistry, University of Bath Claverton Down Bath BA1 7AY UK
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2
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Roca M, Williams IH. Transition-State Vibrational Analysis and Isotope Effects for COMT-Catalyzed Methyl Transfer. J Am Chem Soc 2020; 142:15548-15559. [PMID: 32812761 PMCID: PMC7498148 DOI: 10.1021/jacs.0c07344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Isotopic partition-function ratios (IPFRs) computed for transition structures (TSs) of the methyl-transfer reaction catalyzed by catechol O-methyltransferase and modeled by hybrid QM/MM methods are analyzed. The ability of smaller Hessians to reproduce trends in α-3H3 and 14Cα IPFRs as obtained using the much larger subset QM/MM Hessians from which they are extracted is investigated critically. A 6-atom-extracted Hessian reproduces perfectly the α-T3 IPFR values from the full-subset Hessians of all the TSs but not the α-14CIPFRs. Average AM1/OPLS-AA harmonic frequencies and mean-square amplitudes are presented for the 12 normal modes of the α-CH3 moiety within the active site of several enzymic transition structures, together with QM/MM potential energy scans along each of these modes to assess the degree of anharmonicity. A novel investigation of ponderal effects upon IPFRs suggests that the value for α-14C tends toward a limiting minimum whereas that for α-T3 tends toward a limiting maximum as the mass of the rest of the system increases. The transition vector is dominated by motions of atoms within the donor and acceptor moieties and is very well described as a simple combination of Walden-inversion "umbrella" bending and asymmetric stretching of the SCα and CαO bonds. The contribution of atoms of the protein residues Met40, Tyr68, and Asp141 to the transition vector is extremely small. Average valence force constants for the COMT TS show significant differences from early BEBOVIB estimates which were used in support of the compression hypothesis for catalysis. There is no correlation between TS IPFRs and the nonbonded distances for close contacts between the S atom of SAM and Tyr68 or between any of the H atoms of the transferring methyl group and either Met40 or Asp141.
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Affiliation(s)
- Maite Roca
- Departament de Química Física i Analítica, Universitat Jaume I, 12071 Castellón, Spain
| | - Ian H Williams
- Department of Chemistry, University of Bath, Bath BA2 7AY, United Kingdom
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Świderek K, Porter AJ, Upfold CM, Williams IH. Influence of Dielectric Environment upon Isotope Effects on Glycoside Heterolysis: Computational Evaluation and Atomic Hessian Analysis. J Am Chem Soc 2020; 142:1556-1563. [PMID: 31887034 DOI: 10.1021/jacs.9b11988] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Isotope effects depend upon the polarity of the bulk medium in which a chemical process occurs. Implicit solvent calculations with molecule-shaped cavities show that the equilibrium isotope effect (EIE) for heterolysis of the glycosidic bonds in 5'-methylthioadenosine and in 2-(p-nitrophenoxy)tetrahydropyran, both in water, are very sensitive in the range 2 ≤ ε ≤ 10 to the relative permittivity of the continuum surrounding the oxacarbenium ion. However, different implementations of nominally the same PCM method can lead to opposite trends being predicted for the same molecule. Computational modeling of the influence of the inhomogeneous effective dielectric surrounding a substrate within the protein environment of an enzymic reaction requires an explicit treatment. The EIE (KH/KD) for transfer of cyclopentyl, cyclohexyl, tetrahydrofuranyl and tetrahydropyranyl cations from water to cyclohexane is predicted by B3LYP/6-31+G(d) calculations with implicit solvation and confirmed by B3LYP/6-31+G(d)/OPLS-AA calculations with averaging over many explicit solvation configurations. Atomic Hessian analysis, whereby the full Hessian is reduced to the elements belonging to a single atom at the site of isotopic substitution, reveals a remarkable result for both implicit and explicit solvation: the influence of the solvent environment on these EIEs is essentially captured completely by only a 3 × 3 block of the Hessian, although these values must correctly reflect the influence of the whole environment. QM/MM simulation with ensemble averaging has an important role to play in assisting the meaningful interpretation of observed isotope effects for chemical reactions both in solution and catalyzed by enzymes.
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Affiliation(s)
- Katarzyna Świderek
- Departament de Química Física i Analítica , Universitat Jaume I , 12071 Castellón , Spain.,Department of Chemistry , University of Bath , Bath BA2 7AY , United Kingdom
| | - Alexander J Porter
- Department of Chemistry , University of Bath , Bath BA2 7AY , United Kingdom
| | - Catherine M Upfold
- Department of Chemistry , University of Bath , Bath BA2 7AY , United Kingdom
| | - Ian H Williams
- Department of Chemistry , University of Bath , Bath BA2 7AY , United Kingdom
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Roca M, Upfold CM, Williams IH. Critical evaluation of anharmonicity and configurational averaging in QM/MM modelling of equilibrium isotope effects. Phys Chem Chem Phys 2020; 22:16267-16276. [DOI: 10.1039/d0cp01744b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Anharmonic and harmonic QM (internal modes only): essentially the same; harmonic QM/MM (including external modes): strongly inverse EIE.
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Affiliation(s)
- Maite Roca
- Departament de Química Física i Analítica
- Universitat Jaume I
- 12071 Castellón
- Spain
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Glancy JH, Lee DM, Read EO, Williams IH. Computational simulation of mechanism and isotope effects on acetal heterolysis as a model for glycoside hydrolysis. PURE APPL CHEM 2019. [DOI: 10.1515/pac-2019-0221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Abstract
DFT calculations for the equilibrium isotope effect for deuterium substitution at the anomeric centre Cα in 2-(p-nitrophenoxy)tetrahydropyran with continuum solvation show significant variation in the range of relative permittivity 2 ≤ ε ≤ 10. One-dimensional scans of potential energy (with implicit solvation by water) or of free energy (from QM/MM potentials of mean force with explicit aqueous solvation with a hybrid AM1/OPLS method) for heterolysis of the bond between Cα and the nucleofuge do not show a transition state. A two-dimensional free-energy surface that considers also the distance between Cα and a nucleophilic water indicates a pre-association DN*ANint
‡ mechanism with a transition state involving nucleophilic attack upon an ion-pair intermediate, and this is supported by good agreement between the mean values of the calculated and experimental α-D KIEs. However, the magnitudes of the standard deviations about the mean values for the making and breaking C–O bonds suggest that the transition state is rather plastic, with Cα–Onu≈2 ± 0.4 Å and Cα–Olg≈3 ± 0.5 Å. Not only is nucleophilic solvent assistance necessary, but there is also evidence for electrophilic assistance through specific hydrogen bonding to the nucleofuge.
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Affiliation(s)
- John H. Glancy
- Department of Chemistry , University of Bath , Bath BA2 7AY , UK
| | - Daniel M. Lee
- Department of Chemistry , University of Bath , Bath BA2 7AY , UK
| | - Emily O. Read
- Department of Chemistry , University of Bath , Bath BA2 7AY , UK
| | - Ian H. Williams
- Department of Chemistry , University of Bath , Bath BA2 7AY , UK
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Wilson PB. Recent advances in avian egg science: A review. Poult Sci 2018; 96:3747-3754. [PMID: 28938769 PMCID: PMC5850298 DOI: 10.3382/ps/pex187] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 06/13/2017] [Indexed: 12/21/2022] Open
Abstract
Eggs and egg products form an integral part of the food chain. As such, research into egg structure, function, and production has made an important contribution to the field of poultry science. The past decade has seen significant advances in avian egg science research, with work supplementing our understanding of the nature of the avian egg, and its biological, chemical, and physical properties. Eggshell color, strength, and chemical composition, poultry nutrition, and genetics have all been intensively studied recently, with significant progress being made in a number of these areas. Indeed, with the prevalence of robust theoretical techniques, it is now commonplace to combine experimental investigations with theory, providing a balanced and interdisciplinary perspective.
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Affiliation(s)
- Philippe B Wilson
- Faculty of Health & Life Sciences, De Montfort University, The Gateway, Leicester, LE1 9BH, United Kingdom
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Wilson PB, Williams IH. Computational Modeling of a Caged Methyl Cation: Structure, Energetics, and Vibrational Analysis. J Phys Chem A 2018; 122:1432-1438. [DOI: 10.1021/acs.jpca.7b11836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Philippe B. Wilson
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
- Leicester
School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, United Kingdom
| | - Ian H. Williams
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
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Wilson PB, Williams IH. Influence of Equatorial CH⋅⋅⋅O Interactions on Secondary Kinetic Isotope Effects for Methyl Transfer. Angew Chem Int Ed Engl 2016; 55:3192-5. [PMID: 26823274 PMCID: PMC4770435 DOI: 10.1002/anie.201511708] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Indexed: 11/29/2022]
Abstract
DFT calculations for methyl cation complexed within a constrained cage of water molecules permit the controlled manipulation of the "axial" donor/acceptor distance and the "equatorial" distance to hydrogen-bond acceptors. The kinetic isotope effect k(CH3)/k(CT3) for methyl transfer within a cage with a short axial distance becomes less inverse for shorter equatorial C⋅⋅⋅O distances: a decrease of 0.5 Å results in a 3 % increase at 298 K. Kinetic isotope effects in AdoMet-dependent methyltransferases may be m∧odulated by CH⋅⋅⋅O hydrogen bonding, and factors other than axial compression may contribute, at least partially, to recently reported isotope-effect variations for catechol-O-methyltransferase and its mutant structures.
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Affiliation(s)
| | - Ian H Williams
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK.
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Wilson PB, Williams IH. Influence of Equatorial CH⋅⋅⋅O Interactions on Secondary Kinetic Isotope Effects for Methyl Transfer. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201511708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Ian H. Williams
- Department of Chemistry; University of Bath; Bath BA2 7AY UK
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Abstract
Primary and secondary (18)O equilibrium isotope effects on the acidities of a variety of Brønsted and Lewis acids centered on carbon, boron, nitrogen, and phosphorus were computed by density-functional theory. For many of these acids, the secondary isotope effect was found to be larger than the primary isotope effect. This is a counterintuitive result, because the H atom that is lost is closer to the (18)O atom that is responsible for the primary isotope effect. The relative magnitudes of the isotope effects can be associated with the vibrational frequency and zero-point energy of the X═O vibrations, which are greater than those of the X-O vibrations. However, the difference between these contributions is small, and the major responsibility for the larger secondary isotope effect comes from the moment-of-inertia factor, which depends on the position of the (18)O atom relative to the principal axes of rotation.
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Affiliation(s)
- Charles L Perrin
- Department of Chemistry, University of California-San Diego, La Jolla, California 92093-0358, United States
| | - Kathryn D Burke
- Department of Chemistry, University of California-San Diego, La Jolla, California 92093-0358, United States
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Wilson PB, Williams IH. Critical evaluation of anharmonic corrections to the equilibrium isotope effect for methyl cation transfer from vacuum to dielectric continuum. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1007106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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