1
|
Saberi M, Chikunova A, Ben Bdira F, Cramer-Blok A, Timmer M, Voskamp P, Ubbink M. Bimodal substrate binding in the active site of the glycosidase BcX. FEBS J 2024; 291:4222-4239. [PMID: 39185686 DOI: 10.1111/febs.17251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/02/2024] [Accepted: 08/13/2024] [Indexed: 08/27/2024]
Abstract
Bacillus circulans xylanase (BcX) from the glycoside hydrolase family 11 degrades xylan through a retaining, double-displacement mechanism. The enzyme is thought to hydrolyze glycosidic bonds in a processive manner and has a large, active site cleft, with six subsites allowing the binding of six xylose units. Such an active site architecture suggests that oligomeric xylose substrates can bind in multiple ways. In the crystal structure of the catalytically inactive variant BcX E78Q, the substrate xylotriose is observed in the active site, as well as bound to the known secondary binding site and a third site on the protein surface. Nuclear magnetic resonance (NMR) titrations with xylose oligomers of different lengths yield nonlinear chemical shift trajectories for active site nuclei resonances, indicative of multiple binding orientations for these substrates for which binding and dissociation are in fast exchange on the NMR timescale, exchanging on the micro- to millisecond timescale. Active site binding can be modeled with a 2 : 1 model with dissociation constants in the low and high millimolar range. Extensive mutagenesis of active site residues indicates that tight binding occurs in the glycon binding site and is stabilized by Trp9 and the thumb region. Mutations F125A and W71A lead to large structural rearrangements. Binding at the glycon site is sensed throughout the active site, whereas the weak binding mostly affects the aglycon site. The interactions with the two active site locations are largely independent of each other and of binding at the secondary binding site.
Collapse
Affiliation(s)
- Mahin Saberi
- Leiden Institute of Chemistry, Leiden University, The Netherlands
| | | | - Fredj Ben Bdira
- Leiden Institute of Chemistry, Leiden University, The Netherlands
| | | | - Monika Timmer
- Leiden Institute of Chemistry, Leiden University, The Netherlands
| | - Patrick Voskamp
- Leiden Institute of Chemistry, Leiden University, The Netherlands
| | - Marcellus Ubbink
- Leiden Institute of Chemistry, Leiden University, The Netherlands
| |
Collapse
|
2
|
Díaz-Arenas GL, Lebanov L, Sanz Rodríguez E, Sadiq MM, Paull B, Garnier G, Tanner J. Chemometric optimisation of enzymatic hydrolysis of beechwood xylan to target desired xylooligosaccharides. BIORESOURCE TECHNOLOGY 2022; 352:127041. [PMID: 35318144 DOI: 10.1016/j.biortech.2022.127041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Generation of specific xylooligosaccharides (XOS) is attractive to the pharmaceutical and food industries due to the importance of their structure upon their application. This study used chemometrics to develop a comprehensive computational modelling set to predict the parameters maximising the generation of the desired XOS during enzymatic hydrolysis. The evaluated parameters included pH, temperature, substrate concentration, enzyme dosage and reaction time. A Box-Behnken design was combined with response surface methodology to develop the models. High-performance anion-exchange chromatography coupled with triple-quadrupole mass spectrometry (HPAEC-QqQ-MS) allowed the identification of 22 XOS within beechwood xylan hydrolysates. These data were used to validate the developed models and demonstrated their accuracy in predicting the parameters maximising the generation of the desired XOS. The maximum yields for X2-X6 were 314.2 ± 1.2, 76.6 ± 4.5, 38.4 ± 0.4, 17.8 ± 0.7, and 5.3 ± 0.2 mg/g xylan, respectively. These values map closely to the model predicted values 311.7, 92.6, 43.0, 16.3, and 4.9 mg/g xylan, respectively.
Collapse
Affiliation(s)
- Gloria L Díaz-Arenas
- Bioresource Processing Research Institute of Australia (BioPRIA), Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia; ARC Industrial Transformation Research Hub for Processing Advanced Lignocellulosics (PALS), Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia; Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Leo Lebanov
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia; ARC Industrial Transformation Research Hub for Processing Advanced Lignocellulosics (PALS), School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Estrella Sanz Rodríguez
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia; ARC Industrial Transformation Research Hub for Processing Advanced Lignocellulosics (PALS), School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - M Munir Sadiq
- Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Brett Paull
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia; ARC Industrial Transformation Research Hub for Processing Advanced Lignocellulosics (PALS), School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Gil Garnier
- Bioresource Processing Research Institute of Australia (BioPRIA), Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia; ARC Industrial Transformation Research Hub for Processing Advanced Lignocellulosics (PALS), Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia; Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Joanne Tanner
- Bioresource Processing Research Institute of Australia (BioPRIA), Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia; ARC Industrial Transformation Research Hub for Processing Advanced Lignocellulosics (PALS), Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia; Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia.
| |
Collapse
|
3
|
Ishida T, Parks JM, Smith JC. Insight into the Catalytic Mechanism of GH11 Xylanase: Computational Analysis of Substrate Distortion Based on a Neutron Structure. J Am Chem Soc 2020; 142:17966-17980. [PMID: 32959658 DOI: 10.1021/jacs.0c02148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction mechanism of biomass decomposition by xylanases remains the subject of debate. To clarify the mechanism we investigated the glycosylation step of GH11 xylanase, an enzyme that catalyzes the hydrolysis of lignocellulosic hemicellulose (xylan). Making use of a recent neutron crystal structure, which revealed the protonation states of relevant residues, we used ab initio quantum mechanics/molecular mechanics (QM/MM) calculations to determine the detailed reaction mechanism of the glycosylation step. In particular, our focus is on the controversial question of whether or not an oxocarbenium ion intermediate is formed on the reaction pathway. The calculations support the validity of a basic retaining mechanism within a double-displacement scheme. The estimated free energy barrier of this reaction is ∼18 kcal/mol with QM/MM-CCSD(T)/6-31(+)G**//MP2/6-31+G**/AMBER calculations, and the rate-determining step of the glycosylation is scission of the glycosidic bond after proton transfer from the acidic Glu177. The estimated lifetime of the oxocarbenium ion intermediate (on the order of tens of ps) and the secondary kinetic isotope effect suggest that there is no accumulation of this intermediate on the reaction path, although the intermediate can be transiently formed. In the enzyme-substrate (ES) complex, the carbohydrate structure of the xylose residue at the -1 subsite has a rather distorted (skewed) geometry, and this xylose unit at the active site has an apparent half-chair conformation when the oxocarbenium ion intermediate is formed. The major catalytic role of the protein environment is to orient residues that take part in the initial proton transfer. Because of a fine alignment of catalytic residues, the enzyme can accelerate the glycosylation reaction without paying a reorganization energy penalty.
Collapse
Affiliation(s)
- Toyokazu Ishida
- Research Center for Computational Design of Advanced Functional Materials (CD-FMat), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba 305-8568, Japan
| | - Jerry M Parks
- Center for Molecular Biophysics (CMB), Biosciences Division, Oak Ridge National Laboratory (ORNL), 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
| | - Jeremy C Smith
- Center for Molecular Biophysics (CMB), Biosciences Division, Oak Ridge National Laboratory (ORNL), 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
| |
Collapse
|
4
|
de Meirelles JL, Nepomuceno FC, Peña-García J, Schmidt RR, Pérez-Sánchez H, Verli H. Current Status of Carbohydrates Information in the Protein Data Bank. J Chem Inf Model 2020; 60:684-699. [PMID: 31961683 DOI: 10.1021/acs.jcim.9b00874] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Carbohydrates are well known for their physicochemical, biological, functional, and therapeutic characteristics. Unfortunately, their chemical nature imposes severe challenges for the structural elucidation of these phenomena, impairing not only the depth of our understanding of carbohydrates but also the development of new biotechnological and therapeutic applications based on these molecules. In the recent past, the amount of structural information, obtained mainly from X-ray crystallography, has increased progressively, as well as its quality. In this context, the current work presents a global analysis of the carbohydrate information available in the Protein Data Bank (PDB). From high quality structures, it is clear that most of the data are highly concentrated on a few sets of residue types, on their monosaccharidic forms, and connected by a small diversity of glycosidic linkages. The geometries of these linkages can be mostly associated with the types of linkages instead of residues, while the level of puckering distortion was characterized, quantified, and located in a pseudorotational equilibrium landscape, not only to local minima but also to transitional states. These qualitative and quantitative analyses offer a global picture of the carbohydrate structural content in the PDB, potentially supporting the building of new models for carbohydrate-related biological phenomena at the atomistic level, including new developments on force field parameters.
Collapse
Affiliation(s)
- João L de Meirelles
- Programa de Pos-Graduacao em Biologia Celular e Molecular (PPGBCM), Centro de Biotecnologia , Universidade Federal do Rio Grande do Sul (UFRGS) , Av. Bento Goncalves, 9500 , Porto Alegre , Brazil 91509-900
| | - Felipe C Nepomuceno
- Programa de Pos-Graduacao em Biologia Celular e Molecular (PPGBCM), Centro de Biotecnologia , Universidade Federal do Rio Grande do Sul (UFRGS) , Av. Bento Goncalves, 9500 , Porto Alegre , Brazil 91509-900
| | - Jorge Peña-García
- Bioinformatics and High Performance Computing Research Group (BIO-HPC), Computer Engineering Department , Universidad Católica de Murcia (UCAM) , Murcia , Spain 30107
| | - Ricardo Rodríguez Schmidt
- Bioinformatics and High Performance Computing Research Group (BIO-HPC), Computer Engineering Department , Universidad Católica de Murcia (UCAM) , Murcia , Spain 30107
| | - Horacio Pérez-Sánchez
- Bioinformatics and High Performance Computing Research Group (BIO-HPC), Computer Engineering Department , Universidad Católica de Murcia (UCAM) , Murcia , Spain 30107
| | - Hugo Verli
- Programa de Pos-Graduacao em Biologia Celular e Molecular (PPGBCM), Centro de Biotecnologia , Universidade Federal do Rio Grande do Sul (UFRGS) , Av. Bento Goncalves, 9500 , Porto Alegre , Brazil 91509-900
| |
Collapse
|
5
|
Xiao K, Yu H. Rationalising pK a shifts in Bacillus circulans xylanase with computational studies. Phys Chem Chem Phys 2018; 18:30305-30312. [PMID: 27485091 DOI: 10.1039/c6cp02526a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bacillus circulans xylanase (BcX), a family 11 glycoside hydrolase, catalyses the hydrolysis of xylose polymers with a net retention of stereochemistry. Glu172 in BcX is believed to act as a general acid by protonating the aglycone during glycosylation, and then as a general base to facilitate the deglycosylation step. The key to the dual role of this general acid/base lies in its protonation states, which depend on its intrinsic pKa value and the specific environment which it resides within. To fully understand the detailed molecular features in BcX to establish the dual role of Glu172, we present a combined study based on both atomistic simulations and empirical models to calculate pKa shifts for the general acid/base Glu172 in BcX at different functional states. Its pKa values and those of nearby residues, obtained based on QM/MM free energy calculations, MCCE and PROPKA, show a good agreement with available experimental data. Additionally, our study provides additional insights into the effects of structural and electrostatic perturbations caused by mutations and chemical modifications, suggesting that the local solvation environment and mutagenesis of the residues adjacent to Glu172 establish its dual role during hydrolysis. The strengths and limitations of various methods for calculating pKas and pKa shifts have also been discussed.
Collapse
Affiliation(s)
- Kela Xiao
- School of Chemistry, University of Wollongong, NSW 2522, Australia.
| | - Haibo Yu
- School of Chemistry, University of Wollongong, NSW 2522, Australia. and Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| |
Collapse
|
6
|
Plazinski W, Lonardi A, Hünenberger PH. Revision of the GROMOS 56A6(CARBO) force field: Improving the description of ring-conformational equilibria in hexopyranose-based carbohydrates chains. J Comput Chem 2015; 37:354-65. [PMID: 26525424 DOI: 10.1002/jcc.24229] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 10/03/2015] [Accepted: 10/06/2015] [Indexed: 01/19/2023]
Abstract
This article describes a revised version 56A6(CARBO_R) of the GROMOS 56A6(CARBO) force field for hexopyranose-based carbohydrates. The simulated properties of unfunctionalized hexopyranoses are unaltered with respect to 56A6CARBO . In the context of both O1 -alkylated hexopyranoses and oligosaccharides, the revision stabilizes the regular (4) C1 chair for α-anomers, with the opposite effect for β-anomers. As a result, spurious ring inversions observed in α(1→4)-linked chains when using the original 56A6(CARBO) force field are alleviated. The (4) C1 chair is now the most stable conformation for all d-hexopyranose residues, irrespective of the linkage type and anomery, and of the position of the residue along the chain. The methylation of a d-hexopyranose leads to a systematic shift in the ring-inversion free energy ((4) C1 to (1) C4 ) by 7-8 kJ mol(-1), positive for the α-anomers and negative for the β-anomers, which is qualitatively compatible with the expected enhancement of the anomeric effect upon methylation at O1. The ring-inversion free energies for residues within chains are typically smaller in magnitude compared to those of the monomers, and correlate rather poorly with the latter. This suggests that the crowding of ring substituents upon chain formation alters the ring flexibility in a nonsystematic fashion. In general, the description of carbohydrate chains afforded by 56A6(CARBO_R) suggests a significant extent of ring flexibility, i.e., small but often non-negligible equilibrium populations of inverted chairs, and challenges the "textbook" picture of conformationally locked carbohydrate rings.
Collapse
Affiliation(s)
- Wojciech Plazinski
- Laboratory of Physical Chemistry, ETH Hönggerberg, HCI, Zürich, CH-8093, Switzerland.,J. Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Ul. Niezapominajek 8, Cracow, 30-239, Poland
| | - Alice Lonardi
- Laboratory of Physical Chemistry, ETH Hönggerberg, HCI, Zürich, CH-8093, Switzerland
| | | |
Collapse
|
7
|
Plazinski W, Drach M. The influence of the hexopyranose ring geometry on the conformation of glycosidic linkages investigated using molecular dynamics simulations. Carbohydr Res 2015; 415:17-27. [DOI: 10.1016/j.carres.2015.07.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/20/2015] [Accepted: 07/29/2015] [Indexed: 11/29/2022]
|
8
|
Abstract
The article reviews the significant contributions to, and the present status of, applications of computational methods for the characterization and prediction of protein-carbohydrate interactions. After a presentation of the specific features of carbohydrate modeling, along with a brief description of the experimental data and general features of carbohydrate-protein interactions, the survey provides a thorough coverage of the available computational methods and tools. At the quantum-mechanical level, the use of both molecular orbitals and density-functional theory is critically assessed. These are followed by a presentation and critical evaluation of the applications of semiempirical and empirical methods: QM/MM, molecular dynamics, free-energy calculations, metadynamics, molecular robotics, and others. The usefulness of molecular docking in structural glycobiology is evaluated by considering recent docking- validation studies on a range of protein targets. The range of applications of these theoretical methods provides insights into the structural, energetic, and mechanistic facets that occur in the course of the recognition processes. Selected examples are provided to exemplify the usefulness and the present limitations of these computational methods in their ability to assist in elucidation of the structural basis underlying the diverse function and biological roles of carbohydrates in their dialogue with proteins. These test cases cover the field of both carbohydrate biosynthesis and glycosyltransferases, as well as glycoside hydrolases. The phenomenon of (macro)molecular recognition is illustrated for the interactions of carbohydrates with such proteins as lectins, monoclonal antibodies, GAG-binding proteins, porins, and viruses.
Collapse
Affiliation(s)
- Serge Pérez
- Department of Molecular Pharmacochemistry, CNRS, University Grenoble-Alpes, Grenoble, France.
| | - Igor Tvaroška
- Department of Chemistry, Slovak Academy of Sciences, Bratislava, Slovak Republic; Department of Chemistry, Faculty of Natural Sciences, Constantine The Philosopher University, Nitra, Slovak Republic.
| |
Collapse
|
9
|
Reilly PJ, Rovira C. Computational Studies of Glycoside, Carboxylic Ester, and Thioester Hydrolase Mechanisms: A Review. Ind Eng Chem Res 2015. [DOI: 10.1021/acs.iecr.5b01312] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter J. Reilly
- Department
of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011-2230, United States
| | - Carme Rovira
- Departament de Química Orgànica
and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain
- Institució
Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| |
Collapse
|
10
|
Ardèvol A, Rovira C. Reaction Mechanisms in Carbohydrate-Active Enzymes: Glycoside Hydrolases and Glycosyltransferases. Insights from ab Initio Quantum Mechanics/Molecular Mechanics Dynamic Simulations. J Am Chem Soc 2015; 137:7528-47. [DOI: 10.1021/jacs.5b01156] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Albert Ardèvol
- Departament
de Química Orgànica and Institut de Química Teòrica
i Computacional (IQTCUB), Universitat de Barcelona, Martí
i Franquès 1, 08028 Barcelona, Spain
| | - Carme Rovira
- Departament
de Química Orgànica and Institut de Química Teòrica
i Computacional (IQTCUB), Universitat de Barcelona, Martí
i Franquès 1, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08018 Barcelona, Spain
| |
Collapse
|
11
|
Iglesias-Fernández J, Raich L, Ardèvol A, Rovira C. The complete conformational free energy landscape of β-xylose reveals a two-fold catalytic itinerary for β-xylanases. Chem Sci 2015; 6:1167-1177. [PMID: 29560204 PMCID: PMC5811086 DOI: 10.1039/c4sc02240h] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 10/27/2014] [Indexed: 01/28/2023] Open
Abstract
Unraveling the conformational catalytic itinerary of glycoside hydrolases (GHs) is a growing topic of interest in glycobiology, with major impact in the design of GH inhibitors. β-xylanases are responsible for the hydrolysis of glycosidic bonds in β-xylans, a group of hemicelluloses of high biotechnological interest that are found in plant cell walls. The precise conformations followed by the substrate during catalysis in β-xylanases have not been unambiguously resolved, with three different pathways being proposed from structural analyses. In this work, we compute the conformational free energy landscape (FEL) of β-xylose to predict the most likely catalytic itineraries followed by β-xylanases. The calculations are performed by means of ab initio metadynamics, using the Cremer-Pople puckering coordinates as collective variables. The computed FEL supports only two of the previously proposed itineraries, 2SO → [2,5B]ǂ → 5S1 and 1S3 → [4H3]ǂ → 4C1, which clearly appear in low energy regions of the FEL. Consistently, 2SO and 1S3 are conformations preactivated for catalysis in terms of free energy/anomeric charge and bond distances. The results however exclude the OE → [OS2]ǂ → B2,5 itinerary that has been recently proposed for a family 11 xylanase. Classical and ab initio QM/MM molecular dynamics simulations reveal that, in this case, the observed OE conformation has been enforced by enzyme mutation. These results add a word of caution on using modified enzymes to inform on catalytic conformational itineraries of glycoside hydrolases.
Collapse
Affiliation(s)
- Javier Iglesias-Fernández
- Departament de Química Orgànica and Institut de Química Teòrica i Computacional (IQTCUB) , Universitat de Barcelona , Martí i Franquès 1 , 08028 Barcelona , Spain .
| | - Lluís Raich
- Departament de Química Orgànica and Institut de Química Teòrica i Computacional (IQTCUB) , Universitat de Barcelona , Martí i Franquès 1 , 08028 Barcelona , Spain .
| | - Albert Ardèvol
- Department of Chemistry and Applied Biosciences , ETH Zürich , USI Campus , 6900 Lugano , Switzerland
| | - Carme Rovira
- Departament de Química Orgànica and Institut de Química Teòrica i Computacional (IQTCUB) , Universitat de Barcelona , Martí i Franquès 1 , 08028 Barcelona , Spain .
- Institució Catalana de Recerca i Estudis Avançats (ICREA) , Passeig Lluís Companys , 23 , 08018 Barcelona , Spain
| |
Collapse
|
12
|
Mhlongo NN, Ebrahim M, Skelton AA, Kruger HG, Williams IH, Soliman MES. Dynamics of the thumb-finger regions in a GH11 xylanase Bacillus circulans: comparison between the Michaelis and covalent intermediate. RSC Adv 2015. [DOI: 10.1039/c5ra16836h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The structure and dynamics of B. circulans β-1,4-xylanase (BCX) were comparatively studied utilizing molecular dynamics.
Collapse
Affiliation(s)
- Ndumiso N. Mhlongo
- Molecular Modeling and Drug Design Research Group
- School of Health Sciences University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Mahasin Ebrahim
- Molecular Modeling and Drug Design Research Group
- School of Health Sciences University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Adam A. Skelton
- Molecular Modeling and Drug Design Research Group
- School of Health Sciences University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit
- School of Health Sciences University of KwaZulu-Natal
- Durban 4001
- South Africa
| | | | - Mahmoud E. S. Soliman
- Molecular Modeling and Drug Design Research Group
- School of Health Sciences University of KwaZulu-Natal
- Durban 4001
- South Africa
| |
Collapse
|
13
|
Rönnols J, Manner S, Siegbahn A, Ellervik U, Widmalm G. Exploration of conformational flexibility and hydrogen bonding of xylosides in different solvents, as a model system for enzyme active site interactions. Org Biomol Chem 2014; 11:5465-72. [PMID: 23857412 DOI: 10.1039/c3ob40991k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The predominantly populated conformation of carbohydrates in solution does not necessarily represent the biologically active species; rather, any conformer accessible without too large an energy penalty may be present in a biological pathway. Thus, the conformational preferences of a naphthyl xyloside, which initiates in vivo synthesis of antiproliferative glycosaminoglycans, have been studied by using NMR spectroscopy in a variety of solvents. Equilibria comprising the conformations (4)C1, (2)SO and (1)C4 were found, with a strong dependence on the hydrogen bonding ability of the solvent. Studies of fluorinated analogues revealed a direct hydrogen bond from the hydroxyl group at C2 to the fluorine atom at C4 by a (1h)JF4,HO2 coupling. Hydrogen bond directionality was further established via comparisons of fluorinated levoglucosan molecules.
Collapse
Affiliation(s)
- Jerk Rönnols
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | | | | | | | | |
Collapse
|
14
|
Mhlongo NN, Skelton AA, Kruger G, Soliman ME, Williams IH. A critical survey of average distances between catalytic carboxyl groups in glycoside hydrolases. Proteins 2014; 82:1747-55. [DOI: 10.1002/prot.24528] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 12/20/2013] [Accepted: 01/28/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Ndumiso N. Mhlongo
- Discipline of Pharmaceutical Sciences; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Adam A. Skelton
- Discipline of Pharmaceutical Sciences; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Gert Kruger
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Mahmoud E.S. Soliman
- Discipline of Pharmaceutical Sciences; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Ian H. Williams
- Department of Chemistry; University of Bath; Bath BA2 7AY United Kingdom
| |
Collapse
|
15
|
Plazinski W, Drach M. The dynamics of the conformational changes in the hexopyranose ring: a transition path sampling approach. RSC Adv 2014. [DOI: 10.1039/c4ra03410d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The transition paths corresponding to the conformational rearrangements in the ring of hexapyranose (α-d- and β-d-glucose) molecules were described by applying the transition path sampling method.
Collapse
Affiliation(s)
- Wojciech Plazinski
- Institute of Catalysis and Surface Chemistry
- Polish Academy of Sciences
- 30-239 Cracow, Poland
| | - Mateusz Drach
- Department of Theoretical Chemistry
- Faculty of Chemistry
- UMCS
- 20-031 Lublin, Poland
| |
Collapse
|
16
|
Kellie JL, Wetmore SD. Selecting DFT methods for use in optimizations of enzyme active sites: applications to ONIOM treatments of DNA glycosylases. CAN J CHEM 2013. [DOI: 10.1139/cjc-2012-0506] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
When using a hybrid methodology to treat an enzymatic reaction, many factors contribute to selecting the method for the high-level region, which can be complicated by the presence of dispersion-driven interactions such as π–π stacking. In addition, the proper treatment of the reaction center often requires a large number of heavy atoms to be included in the high-level region, precluding the use of ab initio methods such as MP2 as well as large basis sets, in the optimization step. In the present work, popular DFT methods were tested to identify an appropriate functional for treating the high-level region in ONIOM optimizations of reactions catalyzed by nonmetalloenzymes. Eight different DFT methods (B3LYP, B97-2, MPW1K, MPWB1K, BB1K, B1B95, M06-2X, and ωB97X-D) in combination with four double-ζ quality Pople basis sets were tested for their ability to optimize noncovalent interactions (hydrogen bonding and π–π) and characterize reactions (proton transfer, SN2 hydrolysis, and unimolecular cleavage). Although the primary focus of this study is accurate structure determination, energetics were also examined at both the optimization level of theory, and with triple-ζ quality basis set and select (M06-2X or ωB97X-D) methods. If dispersion-driven interactions exist within the active site, then MPWB1K/6-31G(d,p) or M06-2X/6-31+G(d,p) are recommended for the optimization step with subsequent triple-ζ quality single-point energies. However, since dispersion-corrected functionals (M06-2X and ωB97X-D) generally require diffuse functions to yield appropriate geometries, the possible size of the high-level region is greatly limited with these methods. In contrast, if the model is large enough to recover steric constraints on π–π interactions, then B3LYP with a small basis set performs comparatively well for the optimization step and is significantly less computationally expensive. Interestingly, the functionals that afford the best geometries often do not yield the best energetics, which emphasizes the importance of structural benchmark studies.
Collapse
Affiliation(s)
- Jennifer L. Kellie
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K 3M4, Canada
| | - Stacey D. Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K 3M4, Canada
| |
Collapse
|
17
|
Pan XL, Liu W, Liu JY. Mechanism of the Glycosylation Step Catalyzed by Human α-Galactosidase: A QM/MM Metadynamics Study. J Phys Chem B 2013; 117:484-9. [DOI: 10.1021/jp308747c] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Xiao-Liang Pan
- State Key
Laboratory of Theoretical and Computational Chemistry, Institute of
Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Wei Liu
- State Key
Laboratory of Theoretical and Computational Chemistry, Institute of
Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Jing-Yao Liu
- State Key
Laboratory of Theoretical and Computational Chemistry, Institute of
Theoretical Chemistry, Jilin University, Changchun 130023, China
| |
Collapse
|
18
|
Verma D, Satyanarayana T. Molecular approaches for ameliorating microbial xylanases. BIORESOURCE TECHNOLOGY 2012; 117:360-367. [PMID: 22595098 DOI: 10.1016/j.biortech.2012.04.034] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 04/09/2012] [Accepted: 04/11/2012] [Indexed: 05/31/2023]
Abstract
In industrial processes, chemical catalysis is being replaced by enzyme catalysis, since the latter is environmentally benign, non-persistent and cost effective. Microbial xylanases have significant applications in textile, baking, food and feed industries, and in paper and pulp industries for reducing the chlorine requirement. The hazardous chlorine required for bleaching can be reduced up to 25-30% by including an enzymatic step in the pulp bleaching process. The paper pulp bleaching requires xylanases that are active at alkaline pH and elevated temperatures. The enzymes from the cultured microbes do not perform optimally in the paper industry due to their inadequate stability under the process conditions of high temperature and alkaline pH. This review, therefore, deals with the rationale of molecular approaches such as protein engineering for designing xylanases with improved characteristics to suit the process conditions in industries, and prospects and problems.
Collapse
Affiliation(s)
- Digvijay Verma
- Department of Microbiology, University of Delhi South Campus, New Delhi 110 021, India
| | | |
Collapse
|
19
|
QM/MM study of catalytic mechanism of Xylanase Cex from Cellulomonas fimi. J Mol Graph Model 2012; 37:67-76. [DOI: 10.1016/j.jmgm.2012.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 04/01/2012] [Accepted: 04/17/2012] [Indexed: 12/13/2022]
|
20
|
Whitfield DM. Plausible transition states for glycosylation reactions. Carbohydr Res 2012; 356:180-90. [DOI: 10.1016/j.carres.2012.03.040] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Revised: 03/27/2012] [Accepted: 03/30/2012] [Indexed: 11/29/2022]
|
21
|
Davies GJ, Planas A, Rovira C. Conformational analyses of the reaction coordinate of glycosidases. Acc Chem Res 2012; 45:308-16. [PMID: 21923088 DOI: 10.1021/ar2001765] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The enzymatic hydrolysis of the glycosidic bond is catalyzed by diverse enzymes generically termed glycoside hydrolases (hereafter GHs) or glycosidases. The many sequence-based families of glycosidases have served as a rich hunting ground for enzymologists for years. Not only are these enzymes of fundamental interest, providing paradigms for enzymatic catalysis that extend beyond the bounds of carbohydrate chemistry, but the enzymes themselves play myriad essential roles in diverse biological processes. The wide utility of glycosidases, from their industrial harnessing in the hydrolysis of plant biomass to their roles in human physiology and disease, has engendered a large scientific constituency with an interest in glycosidase chemistry. A fascinating thread of this research, and one with major impact on the design of enzyme inhibitors, is the conformational analysis of reaction pathways within the diverse families. These GH families provide a large pallet of enzymes with which chemists have attempted to depict the conformational landscape of glycosidase action. In this Account, we review three-dimensional insight into the conformational changes directed by glycosidases, primarily from structural observations of the stable enzyme-ligand species adjacent to the transition state (or states) and of enzyme-inhibitor complexes. We further show how recent computational advances dovetail with structural insight to provide a quantum mechanical basis for glycosidase action. The glycosidase-mediated hydrolysis of the acetal or ketal bond in a glycoside may occur with either inversion or retention of the configuration of the anomeric carbon. Inversion involves a single step and transition state, whereas retention, often referred to as the double displacement, is a two-step process with two transition states. The single transition state for the inverting enzymes and the two transition states (those flanking the covalent intermediate) in the double displacement have been shown to have substantial oxocarbenium ion character. The dissociative nature of these transition states results in significant relative positive charge accumulation on the pyranose ring. The delocalization of lone-pair electrons from the ring oxygen that stabilizes the cationic transition state implies that at, or close to, the transition states the pyranose will be distorted away from its lowest energy conformation to one that favors orbital overlap. Over the preceding decade, research has highlighted the harnessing of noncovalent interactions to aid this distortion of the sugar substrates from their lowest energy chair conformation to a variety of different boat, skew boat, and half-chair forms, each of which favors catalysis with a given enzyme and substrate. Crystallographic observation of stable species that flank the transition state (or states), of both retaining and inverting glycosidases, has allowed a description of their conformational itineraries, illustrating how enzymes facilitate the "electrophilic migration" of the anomeric center along the reaction coordinate. The blossoming of computational approaches, such as ab initio metadynamics, has underscored the quantum mechanical basis for glycoside hydrolysis. Conformational analyses highlight not only the itineraries used by enzymes, enabling their inhibition, but are also reflected in the nonenzymatic synthesis of glycosides, wherein chemists mimic strategies found in nature.
Collapse
Affiliation(s)
- Gideon J. Davies
- Structural Biology Laboratory, Department of Chemistry, The University of York, YO10 5DD, United Kingdom
| | - Antoni Planas
- Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, c/Via Augusta 390, 08017 Barcelona, Spain
| | - Carme Rovira
- Computer Simulation & Modeling and Institut de Química Teòrica i Computacional (IQTCUB), Parc Científic de Barcelona, Baldiri Reixac 4, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08018 Barcelona, Spain
| |
Collapse
|
22
|
Lammerts van Bueren A, Otani S, Friis EP, Wilson KS, Davies GJ. Three-dimensional structure of a thermophilic family GH11 xylanase from Thermobifida fusca. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:141-4. [PMID: 22297985 PMCID: PMC3274389 DOI: 10.1107/s1744309111049608] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 11/21/2011] [Indexed: 11/10/2022]
Abstract
Thermostable enzymes employ various structural features dictated at the amino-acid sequence level that allow them to maintain their integrity at higher temperatures. Many hypotheses as to the nature of thermal stability have been proposed, including optimized core hydrophobicity and an increase in charged surface residues to enhance polar solvent interactions for solubility. Here, the three-dimensional structure of the family GH11 xylanase from the moderate thermophile Thermobifida fusca in its trapped covalent glycosyl-enzyme intermediate complex is presented. Interactions with the bound ligand show fewer direct hydrogen bonds from ligand to protein than observed in previous complexes from other species and imply that binding of the xylan substrate involves several water-mediated hydrogen bonds.
Collapse
Affiliation(s)
| | - Suzie Otani
- Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd, Denmark
| | | | - Keith S. Wilson
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, England
| | - Gideon J. Davies
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, England
| |
Collapse
|
23
|
Rönnols J, Burkhardt A, Cumpstey I, Widmalm G. pKa-Determination and Conformational Studies by NMR Spectroscopy of D-Altrose-Containing and other Pseudodisaccharides as Glycosidase Inhibitor Candidates. European J Org Chem 2011. [DOI: 10.1002/ejoc.201101385] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
24
|
Amorim L, Marcelo F, Rousseau C, Nieto L, Jiménez‐Barbero J, Marrot J, Rauter AP, Sollogoub M, Bols M, Blériot Y. Direct Experimental Evidence for the High Chemical Reactivity of α‐ and β‐Xylopyranosides Adopting a
2,5
B
Conformation in Glycosyl Transfer. Chemistry 2011; 17:7345-56. [DOI: 10.1002/chem.201003251] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Indexed: 12/12/2022]
Affiliation(s)
- Luis Amorim
- UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire (UMR 7201), FR 2769, C181, 4 place Jussieu, 75005 Paris (France)
| | - Filipa Marcelo
- UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire (UMR 7201), FR 2769, C181, 4 place Jussieu, 75005 Paris (France)
- Carbohydrate Chemistry Group, CQB‐FCUL, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 1749‐016 Lisbon (Portugal)
| | - Cyril Rousseau
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Kbh Ø (Denmark)
- Present address: Université d'Artois, IUT de Béthune, UCCS Artois, UMR 8181, 1230 rue de l'Université, BP 819, 62408 Béthune cedex (France)
| | - Lidia Nieto
- Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain)
| | | | - Jérôme Marrot
- Institut Lavoisier, Université de Versailles‐Saint‐Quentin, UMR 8180, 78035 Versailles (France)
| | - Amélia P. Rauter
- Carbohydrate Chemistry Group, CQB‐FCUL, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 1749‐016 Lisbon (Portugal)
| | - Matthieu Sollogoub
- UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire (UMR 7201), FR 2769, C181, 4 place Jussieu, 75005 Paris (France)
| | - Mikael Bols
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Kbh Ø (Denmark)
| | - Yves Blériot
- UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire (UMR 7201), FR 2769, C181, 4 place Jussieu, 75005 Paris (France)
- Present address: Université de Poitiers, UMR 6514, Laboratoire “Synthèse et Réactivité des Substances Naturelles”, 40 avenue du Recteur Pineau, 86022 Poitiers Cedex (France)
| |
Collapse
|
25
|
Jitonnom J, Lee VS, Nimmanpipug P, Rowlands HA, Mulholland AJ. Quantum Mechanics/Molecular Mechanics Modeling of Substrate-Assisted Catalysis in Family 18 Chitinases: Conformational Changes and the Role of Asp142 in Catalysis in ChiB. Biochemistry 2011; 50:4697-711. [DOI: 10.1021/bi101362g] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jitrayut Jitonnom
- Computational Simulation and Modeling Laboratory (CSML), Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Vannajan S. Lee
- Computational Simulation and Modeling Laboratory (CSML), Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Piyarat Nimmanpipug
- Computational Simulation and Modeling Laboratory (CSML), Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Heather A. Rowlands
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Adrian J. Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| |
Collapse
|
26
|
Hansen HS, Hünenberger PH. A reoptimized GROMOS force field for hexopyranose-based carbohydrates accounting for the relative free energies of ring conformers, anomers, epimers, hydroxymethyl rotamers, and glycosidic linkage conformers. J Comput Chem 2010; 32:998-1032. [PMID: 21387332 DOI: 10.1002/jcc.21675] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 08/12/2010] [Accepted: 08/17/2010] [Indexed: 11/07/2022]
Abstract
This article presents a reoptimization of the GROMOS 53A6 force field for hexopyranose-based carbohydrates (nearly equivalent to 45A4 for pure carbohydrate systems) into a new version 56A(CARBO) (nearly equivalent to 53A6 for non-carbohydrate systems). This reoptimization was found necessary to repair a number of shortcomings of the 53A6 (45A4) parameter set and to extend the scope of the force field to properties that had not been included previously into the parameterization procedure. The new 56A(CARBO) force field is characterized by: (i) the formulation of systematic build-up rules for the automatic generation of force-field topologies over a large class of compounds including (but not restricted to) unfunctionalized polyhexopyranoses with arbritrary connectivities; (ii) the systematic use of enhanced sampling methods for inclusion of experimental thermodynamic data concerning slow or unphysical processes into the parameterization procedure; and (iii) an extensive validation against available experimental data in solution and, to a limited extent, theoretical (quantum-mechanical) data in the gas phase. At present, the 56A(CARBO) force field is restricted to compounds of the elements C, O, and H presenting single bonds only, no oxygen functions other than alcohol, ether, hemiacetal, or acetal, and no cyclic segments other than six-membered rings (separated by at least one intermediate atom). After calibration, this force field is shown to reproduce well the relative free energies of ring conformers, anomers, epimers, hydroxymethyl rotamers, and glycosidic linkage conformers. As a result, the 56A(CARBO) force field should be suitable for: (i) the characterization of the dynamics of pyranose ring conformational transitions (in simulations on the microsecond timescale); (ii) the investigation of systems where alternative ring conformations become significantly populated; (iii) the investigation of anomerization or epimerization in terms of free-energy differences; and (iv) the design of simulation approaches accelerating the anomerization process along an unphysical pathway.
Collapse
Affiliation(s)
- Halvor S Hansen
- Laboratorium für Physikalische Chemie, ETH Zürich, CH-8093 Zürich, Switzerland
| | | |
Collapse
|
27
|
Williams IH. Catalysis: transition-state molecular recognition? Beilstein J Org Chem 2010; 6:1026-34. [PMID: 21085499 PMCID: PMC2981812 DOI: 10.3762/bjoc.6.117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 10/05/2010] [Indexed: 11/23/2022] Open
Abstract
THE KEY TO UNDERSTANDING THE FUNDAMENTAL PROCESSES OF CATALYSIS IS THE TRANSITION STATE (TS): indeed, catalysis is a transition-state molecular recognition event. Practical objectives, such as the design of TS analogues as potential drugs, or the design of synthetic catalysts (including catalytic antibodies), require prior knowledge of the TS structure to be mimicked. Examples, both old and new, of computational modelling studies are discussed, which illustrate this fundamental concept. It is shown that reactant binding is intrinsically inhibitory, and that attempts to design catalysts that focus simply upon attractive interactions in a binding site may fail. Free-energy changes along the reaction coordinate for S(N)2 methyl transfer catalysed by the enzyme catechol-O-methyl transferase are described and compared with those for a model reaction in water, as computed by hybrid quantum-mechanical/molecular-mechanical molecular dynamics simulations. The case is discussed of molecular recognition in a xylanase enzyme that stabilises its sugar substrate in a (normally unfavourable) boat conformation and in which a single-atom mutation affects the free-energy of activation dramatically.
Collapse
Affiliation(s)
- Ian H Williams
- Department of Chemistry, University of Bath, Bath BA2 7AY, United Kingdom.
| |
Collapse
|
28
|
Ardèvol A, Biarnés X, Planas A, Rovira C. The Conformational Free-Energy Landscape of β-d-Mannopyranose: Evidence for a 1S5 → B2,5 → OS2 Catalytic Itinerary in β-Mannosidases. J Am Chem Soc 2010; 132:16058-65. [DOI: 10.1021/ja105520h] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Albert Ardèvol
- Computer Simulation and Modeling Laboratory and Institut de Química Teòrica i Computacional (IQTCUB), Parc Científic de Barcelona, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08018 Barcelona, Spain
| | - Xevi Biarnés
- Computer Simulation and Modeling Laboratory and Institut de Química Teòrica i Computacional (IQTCUB), Parc Científic de Barcelona, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08018 Barcelona, Spain
| | - Antoni Planas
- Computer Simulation and Modeling Laboratory and Institut de Química Teòrica i Computacional (IQTCUB), Parc Científic de Barcelona, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08018 Barcelona, Spain
| | - Carme Rovira
- Computer Simulation and Modeling Laboratory and Institut de Química Teòrica i Computacional (IQTCUB), Parc Científic de Barcelona, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08018 Barcelona, Spain
| |
Collapse
|
29
|
Petersen L, Ardèvol A, Rovira C, Reilly PJ. Molecular Mechanism of the Glycosylation Step Catalyzed by Golgi α-Mannosidase II: A QM/MM Metadynamics Investigation. J Am Chem Soc 2010; 132:8291-300. [DOI: 10.1021/ja909249u] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Luis Petersen
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, Computer Simulation and Modeling Laboratory (CoSMoLab), Parc Científic de Barcelona, 08028 Barcelona, Spain, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Albert Ardèvol
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, Computer Simulation and Modeling Laboratory (CoSMoLab), Parc Científic de Barcelona, 08028 Barcelona, Spain, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Carme Rovira
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, Computer Simulation and Modeling Laboratory (CoSMoLab), Parc Científic de Barcelona, 08028 Barcelona, Spain, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Peter J. Reilly
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, Computer Simulation and Modeling Laboratory (CoSMoLab), Parc Científic de Barcelona, 08028 Barcelona, Spain, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| |
Collapse
|
30
|
Lammerts van Bueren A, Ardèvol A, Fayers-Kerr J, Luo B, Zhang Y, Sollogoub M, Blériot Y, Rovira C, Davies GJ. Analysis of the reaction coordinate of alpha-L-fucosidases: a combined structural and quantum mechanical approach. J Am Chem Soc 2010; 132:1804-6. [PMID: 20092273 DOI: 10.1021/ja908908q] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The enzymatic hydrolysis of alpha-L-fucosides is of importance in cancer, bacterial infections, and fucosidosis, a neurodegenerative lysosomal storage disorder. Here we show a series of snapshots along the reaction coordinate of a glycoside hydrolase family GH29 alpha-L-fucosidase unveiling a Michaelis (ES) complex in a (1)C(4) (chair) conformation and a covalent glycosyl-enzyme intermediate in (3)S(1) (skew-boat). First principles metadynamics simulations on isolated alpha-L-fucose strongly support a (1)C(4)<-->(3)H(4)<-->(3)S(1) conformational itinerary for the glycosylation step of the reaction mechanism and indicate a strong "preactivation" of the (1)C(4) complex to nucleophilic attack as reflected by free energy, C1-O1/O5-C1 bond length elongation/reduction, C1-O1 bond orientation, and positive charge development around the anomeric carbon. Analysis of an imino sugar inhibitor is consistent with tight binding of a chair-conformed charged species.
Collapse
|
31
|
|
32
|
Vieira DS, Degrève L, Ward RJ. Characterization of temperature dependent and substrate-binding cleft movements in Bacillus circulans family 11 xylanase: a molecular dynamics investigation. Biochim Biophys Acta Gen Subj 2009; 1790:1301-6. [PMID: 19409448 DOI: 10.1016/j.bbagen.2009.04.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2009] [Revised: 04/14/2009] [Accepted: 04/23/2009] [Indexed: 11/30/2022]
Abstract
BACKGROUND Xylanases (EC 3.2.1.8) hydrolyze xylan, one of the most abundant plant polysaccharides found in nature, and have many potential applications in biotechnology. METHODS Molecular dynamics simulations were used to investigate the effects of temperature between 298 to 338 K and xylobiose binding on residues located in the substrate-binding cleft of the family 11 xylanase from Bacillus circulans (BcX). RESULTS In the absence of xylobiose the BcX exhibits temperature dependent movement of the thumb region which adopts an open conformation exposing the active site at the optimum catalytic temperature (328 K). In the presence of substrate, the thumb region restricts access to the active site at all temperatures, and this conformation is maintained by substrate/protein hydrogen bonds involving active site residues, including hydrogen bonds between Tyr69 and the 2' hydroxyl group of the substrate. Substrate access to the active site is regulated by temperature dependent motions that are restricted to the thumb region, and the BcX/substrate complex is stabilized by extensive intermolecular hydrogen bonding with residues in the active site. GENERAL SIGNIFICANCE These results call for a revision of both the "hinge-bending" model for the activity of group 11 xylanases, and the role of Tyr69 in the catalytic mechanism.
Collapse
Affiliation(s)
- Davi Serradella Vieira
- Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto--Universidade de São Paulo Ribeirão Preto, SP, Brazil.
| | | | | |
Collapse
|
33
|
Petersen L, Ardèvol A, Rovira C, Reilly PJ. Mechanism of Cellulose Hydrolysis by Inverting GH8 Endoglucanases: A QM/MM Metadynamics Study. J Phys Chem B 2009; 113:7331-9. [DOI: 10.1021/jp811470d] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Luis Petersen
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, Computer Simulation and Modeling Laboratory (CoSMoLab), Parc Científic de Barcelona, 08028 Barcelona, Spain, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Albert Ardèvol
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, Computer Simulation and Modeling Laboratory (CoSMoLab), Parc Científic de Barcelona, 08028 Barcelona, Spain, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Carme Rovira
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, Computer Simulation and Modeling Laboratory (CoSMoLab), Parc Científic de Barcelona, 08028 Barcelona, Spain, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Peter J. Reilly
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, Computer Simulation and Modeling Laboratory (CoSMoLab), Parc Científic de Barcelona, 08028 Barcelona, Spain, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain, and Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| |
Collapse
|
34
|
Soliman MES, Pernía JJR, Greig IR, Williams IH. Mechanism of glycoside hydrolysis: A comparative QM/MM molecular dynamics analysis for wild type and Y69F mutant retaining xylanases. Org Biomol Chem 2009; 7:5236-44. [DOI: 10.1039/b911644c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|