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Nieto-Fabregat F, Lenza MP, Marseglia A, Di Carluccio C, Molinaro A, Silipo A, Marchetti R. Computational toolbox for the analysis of protein-glycan interactions. Beilstein J Org Chem 2024; 20:2084-2107. [PMID: 39189002 PMCID: PMC11346309 DOI: 10.3762/bjoc.20.180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 08/01/2024] [Indexed: 08/28/2024] Open
Abstract
Protein-glycan interactions play pivotal roles in numerous biological processes, ranging from cellular recognition to immune response modulation. Understanding the intricate details of these interactions is crucial for deciphering the molecular mechanisms underlying various physiological and pathological conditions. Computational techniques have emerged as powerful tools that can help in drawing, building and visualising complex biomolecules and provide insights into their dynamic behaviour at atomic and molecular levels. This review provides an overview of the main computational tools useful for studying biomolecular systems, particularly glycans, both in free state and in complex with proteins, also with reference to the principles, methodologies, and applications of all-atom molecular dynamics simulations. Herein, we focused on the programs that are generally employed for preparing protein and glycan input files to execute molecular dynamics simulations and analyse the corresponding results. The presented computational toolbox represents a valuable resource for researchers studying protein-glycan interactions and incorporates advanced computational methods for building, visualising and predicting protein/glycan structures, modelling protein-ligand complexes, and analyse MD outcomes. Moreover, selected case studies have been reported to highlight the importance of computational tools in studying protein-glycan systems, revealing the capability of these tools to provide valuable insights into the binding kinetics, energetics, and structural determinants that govern specific molecular interactions.
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Affiliation(s)
- Ferran Nieto-Fabregat
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Maria Pia Lenza
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Angela Marseglia
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Cristina Di Carluccio
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Alba Silipo
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Roberta Marchetti
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
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Xue Y, Yu C, Ouyang H, Huang J, Kang X. Uncovering the Molecular Composition and Architecture of the Bacillus subtilis Biofilm via Solid-State NMR Spectroscopy. J Am Chem Soc 2024; 146:11906-11923. [PMID: 38629727 DOI: 10.1021/jacs.4c00889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The complex and dynamic compositions of biofilms, along with their sophisticated structural assembly mechanisms, endow them with exceptional capabilities to thrive in diverse conditions that are typically unfavorable for individual cells. Characterizing biofilms in their native state is significantly challenging due to their intrinsic complexities and the limited availability of noninvasive techniques. Here, we utilized solid-state nuclear magnetic resonance (NMR) spectroscopy to analyze Bacillus subtilis biofilms in-depth. Our data uncover a dynamically distinct organization within the biofilm: a dominant, hydrophilic, and mobile framework interspersed with minor, rigid cores of limited water accessibility. In these heterogeneous rigid cores, the major components are largely self-assembled. TasA fibers, the most robust elements, further provide a degree of mechanical support for the cell aggregates and some lipid vesicles. Notably, rigid cell aggregates can persist even without the major extracellular polymeric substance (EPS) polymers, although this leads to slight variations in their rigidity and water accessibility. Exopolysaccharides are exclusively present in the mobile domain, playing a pivotal role in its water retention property. Specifically, all water molecules are tightly bound within the biofilm matrix. These findings reveal a dual-layered defensive strategy within the biofilm: a diffusion barrier through limited water mobility in the mobile phase and a physical barrier posed by limited water accessibility in the rigid phase. Complementing these discoveries, our comprehensive, in situ compositional analysis is not only essential for delineating the sophisticated biofilm architecture but also reveals the presence of alternative genetic mechanisms for synthesizing exopolysaccharides beyond the known pathway.
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Affiliation(s)
- Yi Xue
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Chenjie Yu
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Han Ouyang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Jiaofang Huang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xue Kang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, China
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Hughes JR, McMorrow KJ, Bovin N, Miller DJ. An oviduct glycan increases sperm lifespan by diminishing the production of ubiquinone and reactive oxygen species†. Biol Reprod 2023; 109:356-366. [PMID: 37427962 PMCID: PMC10502565 DOI: 10.1093/biolre/ioad074] [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: 01/23/2023] [Revised: 06/02/2023] [Accepted: 06/26/2023] [Indexed: 07/11/2023] Open
Abstract
Sperm storage by females after mating for species-dependent periods is used widely among animals with internal fertilization to allow asynchrony between mating and ovulation. Many mammals store sperm in the lower oviduct where specific glycans on oviduct epithelial cells retain sperm to form a reservoir. Binding to oviduct cells suppresses sperm intracellular Ca2+ and increases sperm longevity. We investigated the mechanisms by which a specific oviduct glycan, 3-O-sulfated Lewis X trisaccharide (suLeX), prolongs the lifespan of porcine sperm. Using targeted metabolomics, we found that binding to suLeX diminishes the abundance of 4-hydroxybenzoic acid, the precursor to ubiquinone (also known as Coenzyme Q), 30 min after addition. Ubiquinone functions as an electron acceptor in the electron transport chain (ETC). 3-O-sulfated Lewis X trisaccharide also suppressed the formation of fumarate. A component of the citric acid cycle, fumarate is synthesized by succinate-coenzyme Q reductase, which employs ubiquinone and is also known as Complex II in the ETC. Consistent with the reduced activity of the ETC, the production of harmful reactive oxygen species (ROS) was diminished. The enhanced sperm lifespan in the oviduct may be because of suppressed ROS production because high ROS concentrations have toxic effects on sperm.
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Affiliation(s)
- Jennifer R Hughes
- Department of Animal Sciences and Institute of Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Katie J McMorrow
- Department of Animal Sciences and Institute of Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Nicolai Bovin
- Department of Chemical Biology of Glycans and Lipids, Shemyakin Institute of Bioorganic Chemistry, Moscow, Russia
| | - David J Miller
- Department of Animal Sciences and Institute of Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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4
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Hughes JR, McMorrow KJ, Bovin N, Miller DJ. An oviduct glycan increases sperm lifespan by diminishing ubiquinone and production of reactive oxygen species. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.08.523174. [PMID: 36712093 PMCID: PMC9881936 DOI: 10.1101/2023.01.08.523174] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Sperm storage by females after mating for species-dependent periods is used widely among animals with internal fertilization to allow asynchrony between mating and ovulation. Many mammals store sperm in the lower oviduct where specific glycans on epithelial cells retain sperm to form a reservoir. Binding to oviduct cells suppresses sperm intracellular Ca 2+ and increases sperm longevity. We investigated the mechanisms by which a specific oviduct glycan, 3-O-sulfated Lewis X trisaccharide (suLe X ), prolongs the lifespan of porcine sperm. Using targeted metabolomics, we report that binding to suLe X diminishes the abundance of the precursor to ubiquinone and suppresses formation of fumarate, a specific citric acid cycle component, diminishing the activity of the electron transport chain and reducing the production of harmful reactive oxygen species (ROS). The enhanced sperm lifespan in the oviduct may be due to suppressed ROS production as many reports have demonstrated toxic effects of high ROS concentrations on sperm.
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Gao Z, He Y, He Q, Wei W, Luo Y, Ma Z, Chen W, Chu F, Zhang S, Liu Y, Pan Y. Multidimensional identification of disaccharide isomers based on non-covalent complexes and tandem mass spectrometry. Talanta 2022; 249:123674. [PMID: 35717753 DOI: 10.1016/j.talanta.2022.123674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/01/2022] [Accepted: 06/09/2022] [Indexed: 11/26/2022]
Abstract
Glycans are the most abundant organic polymers in nature. They are essential to living organisms and regulate a wide range of biological functions. However, mass spectrometry-based identification of glycan isomers remains challenging due to the complexity of their structures including their complex compositions, linkages, and anomeric configurations. In this study, two novel complex ions, the mononuclear copper-bound dimeric ions [(Cu2+)(A)(L-His)-H]+ and the mononuclear copper-bound quaternary ions [(Cu2+)(A)(L-Ser)3-H]+ (where A denotes a disaccharide, and L-Ser/His denotes l-serine/histidine), were designed for the collision-induced dissociation-based identification and relative quantification of 14 disaccharide isomers. When the unique fragmentation patterns of the above two types of complex ions were mapped into a three-dimensional vector, all the isomers were completely distinguished. Of note, the established method is able to identify mixtures of linkage isomers only using tandem mass spectrometry based on linkage-specific fragment ions of histidine-based complex ions. Finally, the method was successfully applied to the identification and relative quantification of two disaccharide isomers (lactose and sucrose) in dairy beverages. In conclusion, the established method is sensitive to subtle structural differences in disaccharide isomers and has the potential to be used for the differentiation of various glycans.
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Affiliation(s)
- Zhan Gao
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China
| | - Yuwen He
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China
| | - Quan He
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China
| | - Wei Wei
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China
| | - Yuanqing Luo
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China
| | - Zihan Ma
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China
| | - Weiwei Chen
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China
| | - Fengjian Chu
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, PR China
| | - Shuheng Zhang
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China
| | - Yaqin Liu
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China
| | - Yuanjiang Pan
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, PR China.
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Cañada FJ, Canales Á, Valverde P, de Toro BF, Martínez-Orts M, Phillips PO, Pereda A. Conformational and Structural characterization of carbohydrates and their interactions studied by NMR. Curr Med Chem 2021; 29:1147-1172. [PMID: 34225601 DOI: 10.2174/0929867328666210705154046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/30/2021] [Accepted: 05/12/2021] [Indexed: 11/22/2022]
Abstract
Carbohydrates, either free or as glycans conjugated with other biomolecules, participate in many essential biological processes. Their apparent simplicity in terms of chemical functionality hides an extraordinary diversity and structural complexity. Deeply deciphering at the atomic level their structures is essential to understand their biological function and activities, but it is still a challenging task in need of complementary approaches and no generalized procedures are available to address the study of such complex, natural glycans. The versatility of Nuclear Magnetic Resonance spectroscopy (NMR) often makes it the preferred choice to study glycans and carbohydrates in solution media. The most basic NMR parameters, namely chemical shifts, coupling constants and nuclear Overhauser effects, allow defining short or repetitive chain sequences and characterize their structures and local geometries either in the free state or when interacting with other biomolecules, rendering additional information on the molecular recognition processes. The increased accessibility to carbohydrate molecules extensively or selectively labeled with 13C boosts the resolution and detail that analyzed glycan structures can reach. In turn, structural information derived from NMR, complemented with molecular modeling and theoretical calculations can also provide dynamic information on the conformational flexibility of carbohydrate structures. Furthermore, using partially oriented media or paramagnetic perturbations, it has been possible to introduce additional long-range observables rendering structural information on longer and branched glycan chains. In this review, we provide examples of these studies and an overview of the recent and most relevant NMR applications in the glycobiology field.
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Affiliation(s)
- Francisco Javier Cañada
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas Margarita Salas, CSIC, 28040 Madrid, Spain
| | - Ángeles Canales
- Departamento de Química Orgánica I, Facultad Ciencias Químicas, Universidad Complutense de Madrid, Avd. Complutense s/n, C.P. 28040 Madrid, Spain
| | - Pablo Valverde
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas Margarita Salas, CSIC, 28040 Madrid, Spain
| | - Beatriz Fernández de Toro
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas Margarita Salas, CSIC, 28040 Madrid, Spain
| | - Mónica Martínez-Orts
- Departamento de Química Orgánica I, Facultad Ciencias Químicas, Universidad Complutense de Madrid, Avd. Complutense s/n, C.P. 28040 Madrid, Spain
| | - Paola Oquist Phillips
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas Margarita Salas, CSIC, 28040 Madrid, Spain
| | - Amaia Pereda
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas Margarita Salas, CSIC, 28040 Madrid, Spain
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Multistage mass spectrometry with intelligent precursor selection for N-glycan branching pattern analysis. Carbohydr Polym 2020; 237:116122. [DOI: 10.1016/j.carbpol.2020.116122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 02/10/2020] [Accepted: 03/03/2020] [Indexed: 12/28/2022]
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8
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Zhu H, Ding X, Hou Y, Li Y, Wang M. Structure elucidation and bioactivities of a new polysaccharide from Xiaojin Boletus speciosus Frost. Int J Biol Macromol 2019; 126:697-716. [DOI: 10.1016/j.ijbiomac.2018.12.216] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 12/29/2022]
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9
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Glycans and glycosaminoglycans in neurobiology: key regulators of neuronal cell function and fate. Biochem J 2018; 475:2511-2545. [PMID: 30115748 DOI: 10.1042/bcj20180283] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/14/2018] [Accepted: 07/18/2018] [Indexed: 12/16/2022]
Abstract
The aim of the present study was to examine the roles of l-fucose and the glycosaminoglycans (GAGs) keratan sulfate (KS) and chondroitin sulfate/dermatan sulfate (CS/DS) with selected functional molecules in neural tissues. Cell surface glycans and GAGs have evolved over millions of years to become cellular mediators which regulate fundamental aspects of cellular survival. The glycocalyx, which surrounds all cells, actuates responses to growth factors, cytokines and morphogens at the cellular boundary, silencing or activating downstream signaling pathways and gene expression. In this review, we have focused on interactions mediated by l-fucose, KS and CS/DS in the central and peripheral nervous systems. Fucose makes critical contributions in the area of molecular recognition and information transfer in the blood group substances, cytotoxic immunoglobulins, cell fate-mediated Notch-1 interactions, regulation of selectin-mediated neutrophil extravasation in innate immunity and CD-34-mediated new blood vessel development, and the targeting of neuroprogenitor cells to damaged neural tissue. Fucosylated glycoproteins regulate delivery of synaptic neurotransmitters and neural function. Neural KS proteoglycans (PGs) were examined in terms of cellular regulation and their interactive properties with neuroregulatory molecules. The paradoxical properties of CS/DS isomers decorating matrix and transmembrane PGs and the positive and negative regulatory cues they provide to neurons are also discussed.
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10
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Huang Z, Guan Q, Chen Z, Frydman L, Lin Y. A discrete Fourier-encoded, diagonal-free experiment to simplify homonuclear 2D NMR correlations. J Chem Phys 2017; 147:034201. [PMID: 28734279 DOI: 10.1063/1.4990541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy has long served as an irreplaceable, versatile tool in physics, chemistry, biology, and materials sciences, owing to its ability to study molecular structure and dynamics in detail. In particular, the connectivity of chemical sites within molecules, and thereby molecular structure, becomes visible by multi-dimensional NMR. Homonuclear correlation experiments are a powerful tool for identifying coupled spins. Generally, diagonal peaks in these correlation spectra display the strongest intensities and do not offer any new information beyond the standard one-dimensional spectrum, whereas weaker, symmetrically placed cross peaks contain most of the coupling information. The cross peaks near the diagonal are often affected by the tails of strong diagonal peaks or even obscured entirely by the diagonal. In this paper, we demonstrate a homonuclear encoding approach based on imparting a discrete phase modulation of the targeted cross peaks and combine it with a site-selective sculpting scheme, capable of simplifying the patterns arising in these 2D correlation spectra. The theoretical principles of the new methods are laid out, and experimental observations are rationalized on the basis of theoretical analyses. The ensuing techniques provide a new way to retrieve 2D coupling information within homonuclear spin systems, with enhanced sensitivity, speed, and clarity.
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Affiliation(s)
- Zebin Huang
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China
| | - Quanshuai Guan
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China
| | - Zhong Chen
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China
| | - Lucio Frydman
- Department of Chemical Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Yulan Lin
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China
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Ricard-Blum S, Lisacek F. Glycosaminoglycanomics: where we are. Glycoconj J 2016; 34:339-349. [PMID: 27900575 DOI: 10.1007/s10719-016-9747-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/28/2016] [Accepted: 11/01/2016] [Indexed: 01/21/2023]
Abstract
Glycosaminoglycans regulate numerous physiopathological processes such as development, angiogenesis, innate immunity, cancer and neurodegenerative diseases. Cell surface GAGs are involved in cell-cell and cell-matrix interactions, cell adhesion and signaling, and host-pathogen interactions. GAGs contribute to the assembly of the extracellular matrix and heparan sulfate chains are able to sequester growth factors in the ECM. Their biological activities are regulated by their interactions with proteins. The structural heterogeneity of GAGs, mostly due to chemical modifications occurring during and after their synthesis, makes the development of analytical techniques for their profiling in cells, tissues, and biological fluids, and of computational tools for mining GAG-protein interaction data very challenging. We give here an overview of the experimental approaches used in glycosaminoglycomics, of the major GAG-protein interactomes characterized so far, and of the computational tools and databases available to analyze and store GAG structures and interactions.
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Affiliation(s)
- Sylvie Ricard-Blum
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, UMR 5246 CNRS - Université Lyon 1, INSA Lyon, CPE Lyon, 69622, Villeurbanne Cedex, France.
| | - Frédérique Lisacek
- SIB Swiss Institute of Bioinformatics, 1 Rue Michel-Servet, 1211, Geneva, Switzerland.,Computer Science Department, University of Geneva, Geneva, Switzerland
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12
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Minimally Mutated HIV-1 Broadly Neutralizing Antibodies to Guide Reductionist Vaccine Design. PLoS Pathog 2016; 12:e1005815. [PMID: 27560183 PMCID: PMC4999182 DOI: 10.1371/journal.ppat.1005815] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 07/19/2016] [Indexed: 11/19/2022] Open
Abstract
An optimal HIV vaccine should induce broadly neutralizing antibodies (bnAbs) that neutralize diverse viral strains and subtypes. However, potent bnAbs develop in only a small fraction of HIV-infected individuals, all contain rare features such as extensive mutation, insertions, deletions, and/or long complementarity-determining regions, and some are polyreactive, casting doubt on whether bnAbs to HIV can be reliably induced by vaccination. We engineered two potent VRC01-class bnAbs that minimized rare features. According to a quantitative features frequency analysis, the set of features for one of these minimally mutated bnAbs compared favorably with all 68 HIV bnAbs analyzed and was similar to antibodies elicited by common vaccines. This same minimally mutated bnAb lacked polyreactivity in four different assays. We then divided the minimal mutations into spatial clusters and dissected the epitope components interacting with those clusters, by mutational and crystallographic analyses coupled with neutralization assays. Finally, by synthesizing available data, we developed a working-concept boosting strategy to select the mutation clusters in a logical order following a germline-targeting prime. We have thus developed potent HIV bnAbs that may be more tractable vaccine goals compared to existing bnAbs, and we have proposed a strategy to elicit them. This reductionist approach to vaccine design, guided by antibody and antigen structure, could be applied to design candidate vaccines for other HIV bnAbs or protective Abs against other pathogens. Many HIV vaccine design efforts aim to elicit so-called broadly neutralizing antibodies that bind and neutralize diverse strains and subtypes of the virus. However, these efforts are guided by very unusual antibodies isolated from HIV-infected individuals. These antibodies have rare features that limit their use as direct vaccine templates, because it is unlikely that any vaccine could consistently elicit similar antibodies. We engineered HIV broadly neutralizing antibodies that minimized these rare features and may therefore serve as better leads for HIV vaccine design. Antibodies generally gain affinity for their target epitope by accumulating mutations in a natural process of maturation. Figuring out how to use vaccines to elicit particular kinds of antibodies, with particular kinds of helpful mutations, is a major unsolved challenge for vaccine design. We were able to determine which mutations in our new antibodies are most important and which epitope structures are needed to induce those mutations. This analysis allowed us to deduce a logical strategy, which remains to be tested, for how to guide the maturation of these types of antibodies by vaccination. We propose that this reductionist approach to vaccine design, guided by molecular structure and engineering-oriented to allow for optimization, has promise for designing vaccines against HIV and many other pathogens.
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Singh A, Del Poeta M. Sphingolipidomics: An Important Mechanistic Tool for Studying Fungal Pathogens. Front Microbiol 2016; 7:501. [PMID: 27148190 PMCID: PMC4830811 DOI: 10.3389/fmicb.2016.00501] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Accepted: 03/28/2016] [Indexed: 01/28/2023] Open
Abstract
Sphingolipids form of a unique and complex group of bioactive lipids in fungi. Structurally, sphingolipids of fungi are quite diverse with unique differences in the sphingoid backbone, amide linked fatty acyl chain and the polar head group. Two of the most studied and conserved sphingolipid classes in fungi are the glucosyl- or galactosyl-ceramides and the phosphorylinositol containing phytoceramides. Comprehensive structural characterization and quantification of these lipids is largely based on advanced analytical mass spectrometry based lipidomic methods. While separation of complex lipid mixtures is achieved through high performance liquid chromatography, the soft - electrospray ionization tandem mass spectrometry allows a high sensitivity and selectivity of detection. Herein, we present an overview of lipid extraction, chromatographic separation and mass spectrometry employed in qualitative and quantitative sphingolipidomics in fungi.
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Affiliation(s)
- Ashutosh Singh
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony BrookNY, USA; Veterans Administration Medical Center, NorthportNY, USA
| | - Maurizio Del Poeta
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony BrookNY, USA; Veterans Administration Medical Center, NorthportNY, USA
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Mariethoz J, Khatib K, Alocci D, Campbell MP, Karlsson NG, Packer NH, Mullen EH, Lisacek F. SugarBindDB, a resource of glycan-mediated host-pathogen interactions. Nucleic Acids Res 2016; 44:D1243-50. [PMID: 26578555 PMCID: PMC4702881 DOI: 10.1093/nar/gkv1247] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/22/2015] [Accepted: 10/31/2015] [Indexed: 12/16/2022] Open
Abstract
The SugarBind Database (SugarBindDB) covers knowledge of glycan binding of human pathogen lectins and adhesins. It is a curated database; each glycan-protein binding pair is associated with at least one published reference. The core data element of SugarBindDB is a set of three inseparable components: the pathogenic agent, a lectin/adhesin and a glycan ligand. Each entity (agent, lectin or ligand) is described by a range of properties that are summarized in an entity-dedicated page. Several search, navigation and visualisation tools are implemented to investigate the functional role of glycans in pathogen binding. The database is cross-linked to protein and glycan-relaled resources such as UniProtKB and UniCarbKB. It is tightly bound to the latter via a substructure search tool that maps each ligand to full structures where it occurs. Thus, a glycan-lectin binding pair of SugarBindDB can lead to the identification of a glycan-mediated protein-protein interaction, that is, a lectin-glycoprotein interaction, via substructure search and the knowledge of site-specific glycosylation stored in UniCarbKB. SugarBindDB is accessible at: http://sugarbind.expasy.org.
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Affiliation(s)
- Julien Mariethoz
- Proteome Informatics Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland
| | | | - Davide Alocci
- Proteome Informatics Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland Department of Computer Science, University of Geneva, Geneva, Switzerland
| | - Matthew P Campbell
- Biomolecular Frontiers Research Centre, Macquarie University, North Ryde, NSW, Australia
| | - Niclas G Karlsson
- University of Gothenburg, Sahlgrenska Academy, Institute of Biomedicine, Department of Medical Biochemistry and Cell Biology, Gothenburg, Sweden
| | - Nicolle H Packer
- Biomolecular Frontiers Research Centre, Macquarie University, North Ryde, NSW, Australia
| | | | - Frederique Lisacek
- Proteome Informatics Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland Department of Computer Science, University of Geneva, Geneva, Switzerland
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