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Urban J, Joeres R, Thomès L, Thomsson KA, Bojar D. Navigating the maze of mass spectra: a machine-learning guide to identifying diagnostic ions in O-glycan analysis. Anal Bioanal Chem 2024:10.1007/s00216-024-05500-9. [PMID: 39180595 DOI: 10.1007/s00216-024-05500-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 08/06/2024] [Accepted: 08/09/2024] [Indexed: 08/26/2024]
Abstract
Structural details of oligosaccharides, or glycans, often carry biological relevance, which is why they are typically elucidated using tandem mass spectrometry. Common approaches to distinguish isomers rely on diagnostic glycan fragments for annotating topologies or linkages. Diagnostic fragments are often only known informally among practitioners or stem from individual studies, with unclear validity or generalizability, causing annotation heterogeneity and hampering new analysts. Drawing on a curated set of 237,000 O-glycomics spectra, we here present a rule-based machine learning workflow to uncover quantifiably valid and generalizable diagnostic fragments. This results in fragmentation rules to robustly distinguish common O-glycan isomers for reduced glycans in negative ion mode. We envision this resource to improve glycan annotation accuracy and concomitantly make annotations more transparent and homogeneous across analysts.
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Affiliation(s)
- James Urban
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Roman Joeres
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Saarbrücken, Germany
- Center for Bioinformatics, Saarland University, Saarbrücken, Germany
| | - Luc Thomès
- ULR 7364 - RADEME - Maladies RAres du DÉveloppement embryonnaire et du Métabolisme, CHU Lille, University Lille, 59000, Lille, France
| | - Kristina A Thomsson
- Proteomics Core Facility at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Daniel Bojar
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.
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2
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Dialpuri JS, Bagdonas H, Schofield LC, Pham PT, Holland L, Agirre J. Monitoring carbohydrate 3D structure quality with the Privateer database. Beilstein J Org Chem 2024; 20:931-939. [PMID: 38711584 PMCID: PMC11070961 DOI: 10.3762/bjoc.20.83] [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: 01/30/2024] [Accepted: 04/10/2024] [Indexed: 05/08/2024] Open
Abstract
The remediation of the carbohydrate data of the Protein Data Bank (PDB) has brought numerous enhancements to the findability and interpretability of deposited glycan structures, yet crucial quality indicators are either missing or hard to find on the PDB pages. Without a way to access wider glycochemical context, problematic structures may be taken as fact by keen but inexperienced scientists. The Privateer software is a validation and analysis tool that provides access to a number of metrics and links to external experimental resources, allowing users to evaluate structures using carbohydrate-specific methods. Here, we present the Privateer database, a free resource that aims to complement the growing glycan content of the PDB.
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Affiliation(s)
- Jordan S Dialpuri
- York Structural Biology Laboratory, Department of Chemistry, University of York, UK
| | - Haroldas Bagdonas
- York Structural Biology Laboratory, Department of Chemistry, University of York, UK
| | - Lucy C Schofield
- York Structural Biology Laboratory, Department of Chemistry, University of York, UK
| | - Phuong Thao Pham
- York Structural Biology Laboratory, Department of Chemistry, University of York, UK
| | - Lou Holland
- York Structural Biology Laboratory, Department of Chemistry, University of York, UK
| | - Jon Agirre
- York Structural Biology Laboratory, Department of Chemistry, University of York, UK
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3
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Dialpuri JS, Bagdonas H, Schofield LC, Pham PT, Holland L, Bond PS, Sánchez Rodríguez F, McNicholas SJ, Agirre J. Online carbohydrate 3D structure validation with the Privateer web app. Acta Crystallogr F Struct Biol Commun 2024; 80:30-35. [PMID: 38265073 PMCID: PMC10836424 DOI: 10.1107/s2053230x24000359] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/09/2024] [Indexed: 01/25/2024] Open
Abstract
Owing to the difficulties associated with working with carbohydrates, validating glycan 3D structures prior to deposition into the Protein Data Bank has become a staple of the structure-solution pipeline. The Privateer software provides integrative methods for the validation, analysis, refinement and graphical representation of 3D atomic structures of glycans, both as ligands and as protein modifiers. While Privateer is free software, it requires users to install any of the structural biology software suites that support it or to build it from source code. Here, the Privateer web app is presented, which is always up to date and available to be used online (https://privateer.york.ac.uk) without installation. This self-updating tool, which runs locally on the user's machine, will allow structural biologists to simply and quickly analyse carbohydrate ligands and protein glycosylation from a web browser whilst retaining all confidential information on their devices.
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Affiliation(s)
- Jordan S. Dialpuri
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 3BG, United Kingdom
| | - Haroldas Bagdonas
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 3BG, United Kingdom
| | - Lucy C. Schofield
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 3BG, United Kingdom
| | - Phuong Thao Pham
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 3BG, United Kingdom
| | - Lou Holland
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 3BG, United Kingdom
| | - Paul S. Bond
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 3BG, United Kingdom
| | - Filomeno Sánchez Rodríguez
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 3BG, United Kingdom
| | - Stuart J. McNicholas
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 3BG, United Kingdom
| | - Jon Agirre
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 3BG, United Kingdom
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4
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Melo-Braga MN, Carvalho MB, Ferreira MCE, Lavinder J, Abbasi A, Palmisano G, Thaysen-Andersen M, Sajadi MM, Ippolito GC, Felicori LF. Unveiling the multifaceted landscape of N-glycosylation in antibody variable domains: Insights and implications. Int J Biol Macromol 2024; 257:128362. [PMID: 38029898 PMCID: PMC11003471 DOI: 10.1016/j.ijbiomac.2023.128362] [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: 09/08/2023] [Revised: 11/02/2023] [Accepted: 11/21/2023] [Indexed: 12/01/2023]
Abstract
N-glycosylation at the antibody variable domain has emerged as an important modification influencing antibody function. Despite its significance, information regarding its role and regulation remains limited. To address this gap, we comprehensively explored antibody structures housing N-glycosylation within the Protein Data Bank, yielding fresh insights into this intricate landscape. Our findings revealed that among 208 structures, N-glycosylation was more prevalent in human and mouse antibodies containing IGHV1-8 and IGHV2-2 germline genes, respectively. Moreover, our research highlights the potential for somatic hypermutation to introduce N-glycosylation sites by substituting polar residues (Ser or Thr) in germline variable genes with asparagine. Notably, our study underscores the prevalence of N-glycosylation in antiviral antibodies, especially anti-HIV. Besides antigen-antibody interaction, our findings suggest that N-glycosylation may impact antibody specificity, affinity, and avidity by influencing Fab dimer formation and complementary-determining region orientation. We also identified different glycan structures in HIV and SARS-CoV-2 antibody proteomic datasets, highlighting disparities from the N-glycan structures between PDB antibodies and biological repertoires further highlighting the complexity of N-glycosylation patterns. Our findings significantly enrich our understanding of the N-glycosylation's multifaceted characteristics within the antibody variable domain. Additionally, they underscore the pressing imperative for a more comprehensive characterization of its impact on antibody function.
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Affiliation(s)
- Marcella Nunes Melo-Braga
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Milene Barbosa Carvalho
- Departamento de Ciência da Computação da Universidade Federal de São João Del Rei, São João Del Rei, MG, Brazil
| | - Manuela Cristina Emiliano Ferreira
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Jason Lavinder
- Department of Molecular Biosciences, University of Texas, Austin, TX, USA
| | - Abdolrahim Abbasi
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Giuseppe Palmisano
- Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil; School of Natural Sciences, Macquarie University, Sydney, Australia
| | - Morten Thaysen-Andersen
- School of Natural Sciences, Macquarie University, Sydney, Australia; Institute for Glyco-core Research (iGCORE), Nagoya University, Nagoya, Japan
| | - Mohammad M Sajadi
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Gregory C Ippolito
- Department of Molecular Biosciences, University of Texas, Austin, TX, USA
| | - Liza F Felicori
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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5
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Abstract
Glycoscience assembles all the scientific disciplines involved in studying various molecules and macromolecules containing carbohydrates and complex glycans. Such an ensemble involves one of the most extensive sets of molecules in quantity and occurrence since they occur in all microorganisms and higher organisms. Once the compositions and sequences of these molecules are established, the determination of their three-dimensional structural and dynamical features is a step toward understanding the molecular basis underlying their properties and functions. The range of the relevant computational methods capable of addressing such issues is anchored by the specificity of stereoelectronic effects from quantum chemistry to mesoscale modeling throughout molecular dynamics and mechanics and coarse-grained and docking calculations. The Review leads the reader through the detailed presentations of the applications of computational modeling. The illustrations cover carbohydrate-carbohydrate interactions, glycolipids, and N- and O-linked glycans, emphasizing their role in SARS-CoV-2. The presentation continues with the structure of polysaccharides in solution and solid-state and lipopolysaccharides in membranes. The full range of protein-carbohydrate interactions is presented, as exemplified by carbohydrate-active enzymes, transporters, lectins, antibodies, and glycosaminoglycan binding proteins. A final section features a list of 150 tools and databases to help address the many issues of structural glycobioinformatics.
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Affiliation(s)
- Serge Perez
- Centre de Recherche sur les Macromolecules Vegetales, University of Grenoble-Alpes, Centre National de la Recherche Scientifique, Grenoble F-38041, France
| | - Olga Makshakova
- FRC Kazan Scientific Center of Russian Academy of Sciences, Kazan Institute of Biochemistry and Biophysics, Kazan 420111, Russia
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6
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Rao RM, Dauchez M, Baud S. How molecular modelling can better broaden the understanding of glycosylations. Curr Opin Struct Biol 2022; 75:102393. [PMID: 35679802 DOI: 10.1016/j.sbi.2022.102393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/31/2022] [Accepted: 04/18/2022] [Indexed: 11/03/2022]
Abstract
Glycosylations are among the most ubiquitous post-translational modifications (PTMs) in proteins, and the effects of their perturbations are seen in various diseases such as cancers, diabetes and arthritis to name a few. Yet they remain one of the most enigmatic aspects of protein structure and function. On the other hand, molecular modelling techniques have been rapidly bridging this knowledge gap since the last decade. In this review, we discuss how these techniques have proven to be indispensable for a better understanding of the role of glycosylations in glycoprotein structure and function.
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Affiliation(s)
- Rajas M Rao
- Université de Reims Champagne Ardenne, CNRS UMR 7369, MEDyC, Reims, 51687, France
| | - Manuel Dauchez
- Université de Reims Champagne Ardenne, CNRS UMR 7369, MEDyC, Reims, 51687, France.
| | - Stéphanie Baud
- Université de Reims Champagne Ardenne, CNRS UMR 7369, MEDyC, Reims, 51687, France
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7
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Atanasova M, Nicholls RA, Joosten RP, Agirre J. Updated restraint dictionaries for carbohydrates in the pyranose form. Acta Crystallogr D Struct Biol 2022; 78:455-465. [PMID: 35362468 PMCID: PMC8972801 DOI: 10.1107/s2059798322001103] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 01/31/2022] [Indexed: 11/10/2022] Open
Abstract
Restraint dictionaries are used during macromolecular structure refinement to encapsulate intramolecular connectivity and geometric information. These dictionaries allow previously determined `ideal' values of features such as bond lengths, angles and torsions to be used as restraint targets. During refinement, restraints influence the model to adopt a conformation that agrees with prior observation. This is especially important when refining crystal structures of glycosylated proteins, as their resolutions tend to be worse than those of nonglycosylated proteins. Pyranosides, the overwhelming majority component in all forms of protein glycosylation, often display conformational errors in crystal structures. Whilst many of these flaws usually relate to model building, refinement issues may also have their root in suboptimal restraint dictionaries. In order to avoid subsequent misinterpretation and to improve the quality of all pyranose monosaccharide entries in the CCP4 Monomer Library, new dictionaries with improved ring torsion restraints, coordinates reflecting the lowest-energy ring pucker and updated geometry have been produced and evaluated. These new dictionaries are now part of the CCP4 Monomer Library and will be released with CCP4 version 8.0.
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Affiliation(s)
- Mihaela Atanasova
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Robert A. Nicholls
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Robbie P. Joosten
- Biochemistry Department, Netherlands Cancer Institute, Amsterdam, The Netherlands
- Oncode Institute, The Netherlands
| | - Jon Agirre
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
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8
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Wu H, Crost EH, Owen CD, van Bakel W, Martínez Gascueña A, Latousakis D, Hicks T, Walpole S, Urbanowicz PA, Ndeh D, Monaco S, Sánchez Salom L, Griffiths R, Reynolds RS, Colvile A, Spencer DIR, Walsh M, Angulo J, Juge N. The human gut symbiont Ruminococcus gnavus shows specificity to blood group A antigen during mucin glycan foraging: Implication for niche colonisation in the gastrointestinal tract. PLoS Biol 2021; 19:e3001498. [PMID: 34936658 PMCID: PMC8730463 DOI: 10.1371/journal.pbio.3001498] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 01/05/2022] [Accepted: 11/26/2021] [Indexed: 12/24/2022] Open
Abstract
The human gut symbiont Ruminococcus gnavus displays strain-specific repertoires of glycoside hydrolases (GHs) contributing to its spatial location in the gut. Sequence similarity network analysis identified strain-specific differences in blood-group endo-β-1,4-galactosidase belonging to the GH98 family. We determined the substrate and linkage specificities of GH98 from R. gnavus ATCC 29149, RgGH98, against a range of defined oligosaccharides and glycoconjugates including mucin. We showed by HPAEC-PAD and LC-FD-MS/MS that RgGH98 is specific for blood group A tetrasaccharide type II (BgA II). Isothermal titration calorimetry (ITC) and saturation transfer difference (STD) NMR confirmed RgGH98 affinity for blood group A over blood group B and H antigens. The molecular basis of RgGH98 strict specificity was further investigated using a combination of glycan microarrays, site-directed mutagenesis, and X-ray crystallography. The crystal structures of RgGH98 in complex with BgA trisaccharide (BgAtri) and of RgGH98 E411A with BgA II revealed a dedicated hydrogen network of residues, which were shown by site-directed mutagenesis to be critical to the recognition of the BgA epitope. We demonstrated experimentally that RgGH98 is part of an operon of 10 genes that is overexpresssed in vitro when R. gnavus ATCC 29149 is grown on mucin as sole carbon source as shown by RNAseq analysis and RT-qPCR confirmed RgGH98 expression on BgA II growth. Using MALDI-ToF MS, we showed that RgGH98 releases BgAtri from mucin and that pretreatment of mucin with RgGH98 confered R. gnavus E1 the ability to grow, by enabling the E1 strain to metabolise BgAtri and access the underlying mucin glycan chain. These data further support that the GH repertoire of R. gnavus strains enable them to colonise different nutritional niches in the human gut and has potential applications in diagnostic and therapeutics against infection.
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Affiliation(s)
- Haiyang Wu
- Quadram Institute Bioscience, Norwich, United Kingdom
| | | | - C David Owen
- Diamond Light Source Ltd, Didcot, United Kingdom
- Research Complex at Harwell, Didcot, United Kingdom
| | | | | | | | - Thomas Hicks
- University of East Anglia, Norwich, United Kingdom
| | | | | | - Didier Ndeh
- Quadram Institute Bioscience, Norwich, United Kingdom
| | | | | | | | | | - Anna Colvile
- Diamond Light Source Ltd, Didcot, United Kingdom
- Research Complex at Harwell, Didcot, United Kingdom
| | | | - Martin Walsh
- Diamond Light Source Ltd, Didcot, United Kingdom
- Research Complex at Harwell, Didcot, United Kingdom
| | - Jesus Angulo
- University of East Anglia, Norwich, United Kingdom
- Universidad de Sevilla and Instituto de Investigaciones Químicas, Sevilla, Spain
| | - Nathalie Juge
- Quadram Institute Bioscience, Norwich, United Kingdom
- * E-mail:
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9
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Nicholls RA, Joosten RP, Long F, Wojdyr M, Lebedev A, Krissinel E, Catapano L, Fischer M, Emsley P, Murshudov GN. Modelling covalent linkages in CCP4. Acta Crystallogr D Struct Biol 2021; 77:712-726. [PMID: 34076587 PMCID: PMC8171069 DOI: 10.1107/s2059798321001753] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 02/12/2021] [Indexed: 11/10/2022] Open
Abstract
In this contribution, the current protocols for modelling covalent linkages within the CCP4 suite are considered. The mechanism used for modelling covalent linkages is reviewed: the use of dictionaries for describing changes to stereochemistry as a result of the covalent linkage and the application of link-annotation records to structural models to ensure the correct treatment of individual instances of covalent linkages. Previously, linkage descriptions were lacking in quality compared with those of contemporary component dictionaries. Consequently, AceDRG has been adapted for the generation of link dictionaries of the same quality as for individual components. The approach adopted by AceDRG for the generation of link dictionaries is outlined, which includes associated modifications to the linked components. A number of tools to facilitate the practical modelling of covalent linkages available within the CCP4 suite are described, including a new restraint-dictionary accumulator, the Make Covalent Link tool and AceDRG interface in Coot, the 3D graphical editor JLigand and the mechanisms for dealing with covalent linkages in the CCP4i2 and CCP4 Cloud environments. These integrated solutions streamline and ease the covalent-linkage modelling workflow, seamlessly transferring relevant information between programs. Current recommended practice is elucidated by means of instructive practical examples. By summarizing the different approaches to modelling linkages that are available within the CCP4 suite, limitations and potential pitfalls that may be encountered are highlighted in order to raise awareness, with the intention of improving the quality of future modelled covalent linkages in macromolecular complexes.
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Affiliation(s)
- Robert A. Nicholls
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Robbie P. Joosten
- Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
- Oncode Institute, The Netherlands
| | - Fei Long
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Marcin Wojdyr
- Global Phasing Limited, Sheraton House, Castle Park, Cambridge CB3 0AX, United Kingdom
| | - Andrey Lebedev
- CCP4, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom
| | - Eugene Krissinel
- CCP4, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom
| | - Lucrezia Catapano
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
- Randall Centre for Cell and Molecular Biophysics, Faculty of Life Sciences and Medicine, King’s College London, London SE1 9RT, United Kingdom
| | - Marcus Fischer
- Chemical Biology and Therapeutics and Structural Biology, St Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-3678, USA
| | - Paul Emsley
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Garib N. Murshudov
- Structural Studies, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
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10
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Boittier ED, Burns JM, Gandhi NS, Ferro V. GlycoTorch Vina: Docking Designed and Tested for Glycosaminoglycans. J Chem Inf Model 2020; 60:6328-6343. [PMID: 33152249 DOI: 10.1021/acs.jcim.0c00373] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Glycosaminoglycans (GAGs) are a family of anionic carbohydrates that play an essential role in the physiology and pathology of all eukaryotic life forms. Experimental determination of GAG-protein complexes is challenging due to their difficult isolation from biological sources, natural heterogeneity, and conformational flexibility-including possible ring puckering of sulfated iduronic acid from 1C4 to 2SO conformation. To overcome these challenges, we present GlycoTorch Vina (GTV), a molecular docking tool based on the carbohydrate docking program VinaCarb (VC). Our program is unique in that it contains parameters to model 2SO sugars while also supporting glycosidic linkages specific to GAGs. We discuss how crystallographic models of carbohydrates can be biased by the choice of refinement software and structural dictionaries. To overcome these variations, we carefully curated 12 of the best available GAG and GAG-like crystal structures (ranging from tetra- to octasaccharides or longer) obtained from the PDB-REDO server and refined using the same protocol. Both GTV and VC produced pose predictions with a mean root-mean-square deviation (RMSD) of 3.1 Å from the native crystal structure-a statistically significant improvement when compared to AutoDock Vina (4.5 Å) and the commercial software Glide (5.9 Å). Examples of how real-space correlation coefficients can be used to better assess the accuracy of docking pose predictions are given. Comparisons between statistical distributions of empirical "salt bridge" interactions, relevant to GAGs, were compared to density functional theory (DFT) studies of model salt bridges, and water-mediated salt bridges; however, there was generally a poor agreement between these data. Water bridges appear to play an important, yet poorly understood, role in the structures of GAG-protein complexes. To aid in the rapid prototyping of future pose scoring functions, we include a module that allows users to include their own torsional and nonbonded parameters.
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Affiliation(s)
- Eric D Boittier
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jed M Burns
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Neha S Gandhi
- Chemistry and Physics, Centre for Genomics and Personalised Health, Faculty of Science and Engineering, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Vito Ferro
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
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11
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Scherbinina SI, Toukach PV. Three-Dimensional Structures of Carbohydrates and Where to Find Them. Int J Mol Sci 2020; 21:E7702. [PMID: 33081008 PMCID: PMC7593929 DOI: 10.3390/ijms21207702] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 02/06/2023] Open
Abstract
Analysis and systematization of accumulated data on carbohydrate structural diversity is a subject of great interest for structural glycobiology. Despite being a challenging task, development of computational methods for efficient treatment and management of spatial (3D) structural features of carbohydrates breaks new ground in modern glycoscience. This review is dedicated to approaches of chemo- and glyco-informatics towards 3D structural data generation, deposition and processing in regard to carbohydrates and their derivatives. Databases, molecular modeling and experimental data validation services, and structure visualization facilities developed for last five years are reviewed.
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Affiliation(s)
- Sofya I. Scherbinina
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Science, Leninsky prospect 47, 119991 Moscow, Russia
- Higher Chemical College, D. Mendeleev University of Chemical Technology of Russia, Miusskaya Square 9, 125047 Moscow, Russia
| | - Philip V. Toukach
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Science, Leninsky prospect 47, 119991 Moscow, Russia
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12
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Bagdonas H, Ungar D, Agirre J. Leveraging glycomics data in glycoprotein 3D structure validation with Privateer. Beilstein J Org Chem 2020; 16:2523-2533. [PMID: 33093930 PMCID: PMC7554661 DOI: 10.3762/bjoc.16.204] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 10/06/2020] [Indexed: 12/20/2022] Open
Abstract
The heterogeneity, mobility and complexity of glycans in glycoproteins have been, and currently remain, significant challenges in structural biology. These aspects present unique problems to the two most prolific techniques: X-ray crystallography and cryo-electron microscopy. At the same time, advances in mass spectrometry have made it possible to get deeper insights on precisely the information that is most difficult to recover by structure solution methods: the full-length glycan composition, including linkage details for the glycosidic bonds. The developments have given rise to glycomics. Thankfully, several large scale glycomics initiatives have stored results in publicly available databases, some of which can be accessed through API interfaces. In the present work, we will describe how the Privateer carbohydrate structure validation software has been extended to harness results from glycomics projects, and its use to greatly improve the validation of 3D glycoprotein structures.
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Affiliation(s)
- Haroldas Bagdonas
- York Structural Biology Laboratory, Department of Chemistry, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Daniel Ungar
- Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Jon Agirre
- York Structural Biology Laboratory, Department of Chemistry, University of York, Wentworth Way, York, YO10 5DD, UK
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13
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A chemical interpretation of protein electron density maps in the worldwide protein data bank. PLoS One 2020; 15:e0236894. [PMID: 32785279 PMCID: PMC7423092 DOI: 10.1371/journal.pone.0236894] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/15/2020] [Indexed: 11/29/2022] Open
Abstract
High-quality three-dimensional structural data is of great value for the functional interpretation of biomacromolecules, especially proteins; however, structural quality varies greatly across the entries in the worldwide Protein Data Bank (wwPDB). Since 2008, the wwPDB has required the inclusion of structure factors with the deposition of x-ray crystallographic structures to support the independent evaluation of structures with respect to the underlying experimental data used to derive those structures. However, interpreting the discrepancies between the structural model and its underlying electron density data is difficult, since derived sigma-scaled electron density maps use arbitrary electron density units which are inconsistent between maps from different wwPDB entries. Therefore, we have developed a method that converts electron density values from sigma-scaled electron density maps into units of electrons. With this conversion, we have developed new methods that can evaluate specific regions of an x-ray crystallographic structure with respect to a physicochemical interpretation of its corresponding electron density map. We have systematically compared all deposited x-ray crystallographic protein models in the wwPDB with their underlying electron density maps, if available, and characterized the electron density in terms of expected numbers of electrons based on the structural model. The methods generated coherent evaluation metrics throughout all PDB entries with associated electron density data, which are consistent with visualization software that would normally be used for manual quality assessment. To our knowledge, this is the first attempt to derive units of electrons directly from electron density maps without the aid of the underlying structure factors. These new metrics are biochemically-informative and can be extremely useful for filtering out low-quality structural regions from inclusion into systematic analyses that span large numbers of PDB entries. Furthermore, these new metrics will improve the ability of non-crystallographers to evaluate regions of interest within PDB entries, since only the PDB structure and the associated electron density maps are needed. These new methods are available as a well-documented Python package on GitHub and the Python Package Index under a modified Clear BSD open source license.
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14
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Hendrickx J, Tran V, Sanejouand YH. Numerous severely twisted N-acetylglucosamine conformations found in the protein databank. Proteins 2020; 88:1376-1383. [PMID: 32506721 DOI: 10.1002/prot.25957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 05/12/2020] [Accepted: 05/27/2020] [Indexed: 11/11/2022]
Abstract
Taking advantage of the known planarity of the N-acetyl group of N-acetylglucosamine, an analysis of the quality of carbohydrate structures found in the protein databank was performed. Few obvious defects of the local geometry of the carbonyl group were observed. However, the N-acetyl group was often found in the less favorable cis conformation (12% of the cases). It was also found severely twisted in numerous instances, especially in structures with a resolution poorer than 1.9 Å determined between 2000 and 2015. Though the automated PDB-REDO procedure has proved able to improve nearly 85% of the structural models deposited to the PDB, and does prove able to cure most severely twisted conformations of the N-acetyl group, it fails to correct its high rate of cis conformations. More generally, for structures with a resolution poorer than 1.6 Å, it produces N-acetylglucosamine models in slightly poorer agreement with experimental data, as measured using real-space correlation coefficients. Significant improvements are thus still needed, at least as far as this carbohydrate structure is concerned.
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Affiliation(s)
| | - Vinh Tran
- UFIP, UMR CNRS 6286, Université de Nantes, Nantes, France
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15
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Atanasova M, Bagdonas H, Agirre J. Structural glycobiology in the age of electron cryo-microscopy. Curr Opin Struct Biol 2020; 62:70-78. [DOI: 10.1016/j.sbi.2019.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/20/2019] [Accepted: 12/02/2019] [Indexed: 01/05/2023]
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16
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Lange J, Baakman C, Pistorius A, Krieger E, Hooft R, Joosten RP, Vriend G. Facilities that make the PDB data collection more powerful. Protein Sci 2019; 29:330-344. [PMID: 31724231 PMCID: PMC6933850 DOI: 10.1002/pro.3788] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 11/11/2019] [Indexed: 01/13/2023]
Abstract
We describe a series of databases and tools that directly or indirectly support biomedical research on macromolecules, with focus on their applicability in protein structure bioinformatics research. DSSP, that determines secondary structures of proteins, has been updated to work well with extremely large structures in multiple formats. The PDBREPORT database that lists anomalies in protein structures has been remade to remove many small problems. These reports are now available as PDF-formatted files with a computer-readable summary. The VASE software has been added to analyze and visualize HSSP multiple sequence alignments for protein structures. The Lists collection of databases has been extended with a series of databases, most noticeably with a database that gives each protein structure a grade for usefulness in protein structure bioinformatics projects. The PDB-REDO collection of reanalyzed and re-refined protein structures that were solved by X-ray crystallography has been improved by dealing better with sugar residues and with hydrogen bonds, and adding many missing surface loops. All academic software underlying these protein structure bioinformatics applications and databases are now publicly accessible, either directly from the authors or from the GitHub software repository.
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Affiliation(s)
- Joanna Lange
- Bio-Prodict, Nijmegen, The Netherlands.,Centre for Molecular and Biomolecular Informatics (CMBI), Radboudumc, Nijmegen, The Netherlands
| | - Coos Baakman
- Centre for Molecular and Biomolecular Informatics (CMBI), Radboudumc, Nijmegen, The Netherlands
| | - Arthur Pistorius
- Centre for Molecular and Biomolecular Informatics (CMBI), Radboudumc, Nijmegen, The Netherlands
| | - Elmar Krieger
- Centre for Molecular and Biomolecular Informatics (CMBI), Radboudumc, Nijmegen, The Netherlands
| | - Rob Hooft
- Department of Computer Science, Dutch Techcentre for Life Sciences (DTL), Amsterdam, The Netherlands.,Department of Computer Science, Vrije Universiteit Amsterdam (VU), Amsterdam, The Netherlands
| | - Robbie P Joosten
- Biochemistry department, Netherlands Cancer Institute (NKI), Amsterdam, The Netherlands
| | - Gert Vriend
- Centre for Molecular and Biomolecular Informatics (CMBI), Radboudumc, Nijmegen, The Netherlands.,Baco Institute of Protein Science (BIPS), Mindoro, Philippines
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17
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van Beusekom B, Wezel N, Hekkelman ML, Perrakis A, Emsley P, Joosten RP. Building and rebuilding N-glycans in protein structure models. Acta Crystallogr D Struct Biol 2019; 75:416-425. [PMID: 30988258 PMCID: PMC6465985 DOI: 10.1107/s2059798319003875] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 03/20/2019] [Indexed: 01/16/2023] Open
Abstract
N-Glycosylation is one of the most common post-translational modifications and is implicated in, for example, protein folding and interaction with ligands and receptors. N-Glycosylation trees are complex structures of linked carbohydrate residues attached to asparagine residues. While carbohydrates are typically modeled in protein structures, they are often incomplete or have the wrong chemistry. Here, new tools are presented to automatically rebuild existing glycosylation trees, to extend them where possible, and to add new glycosylation trees if they are missing from the model. The method has been incorporated in the PDB-REDO pipeline and has been applied to build or rebuild 16 452 carbohydrate residues in 11 651 glycosylation trees in 4498 structure models, and is also available from the PDB-REDO web server. With better modeling of N-glycosylation, the biological function of this important modification can be better and more easily understood.
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Affiliation(s)
- Bart van Beusekom
- Department of Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Natasja Wezel
- Department of Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Maarten L. Hekkelman
- Department of Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Anastassis Perrakis
- Department of Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Paul Emsley
- MRC Laboratory for Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, England
| | - Robbie P. Joosten
- Department of Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
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18
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Agirre J, van Raaij MJ. Carbohydrate structure hits the groove. Acta Crystallogr F Struct Biol Commun 2018; 74:441-442. [PMID: 30084392 PMCID: PMC6096480 DOI: 10.1107/s2053230x18010853] [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: 11/10/2022] Open
Abstract
An introduction to the Acta Cryst. F special issue on glycoproteins and protein–carbohydrate complexes in which the contents, the current state of the field and the future of glycan structural biology are briefly discussed.
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Affiliation(s)
- Jon Agirre
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Mark J. van Raaij
- Department of Molecular Structure, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, E-28049 Madrid, Spain
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