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Carboni F, Adamo R. Structure-based glycoconjugate vaccine design: The example of Group B Streptococcus type III capsular polysaccharide. Drug Discov Today Technol 2020; 35-36:23-33. [PMID: 33388125 DOI: 10.1016/j.ddtec.2020.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/22/2020] [Accepted: 11/05/2020] [Indexed: 06/12/2023]
Abstract
Microbial surface polysaccharides are important virulence factors and targets for vaccine development. Glycoconjugate vaccines, obtained by covalently linking carbohydrates and proteins, are well established tools for prevention of bacterial infections. Elucidation of the minimal portion involved in the interactions with functional antibodies is of utmost importance for the understanding of their mechanism of induction of protective immune responses and the design of synthetic glycan based vaccines. Typically, this is achieved by combination of different techniques, which include ELISA, glycoarray, Surface Plasmon Resonance in conjunction with approaches for mapping at atomic level the position involved in binding, such as Saturation Transfer NMR and X-ray crystallography. This review provides an overview of the structural studies performed to map glycan epitopes (glycotopes), with focus on the highly complex structure of Group B Streptococcus type III (GBSIII) capsular polysaccharide. Furthermore, it describes the rational process followed to translate the obtained information into the design of a protective glycoconjugate vaccine based on a well-defined synthetic glycan epitope.
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Bezerra FF, Vignovich WP, Aderibigbe AO, Liu H, Sharp JS, Doerksen RJ, Pomin VH. Conformational properties of l-fucose and the tetrasaccharide building block of the sulfated l-fucan from Lytechinus variegatus. J Struct Biol 2019; 209:107407. [PMID: 31698075 DOI: 10.1016/j.jsb.2019.107407] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/07/2019] [Accepted: 10/23/2019] [Indexed: 01/19/2023]
Abstract
Although the 3D structure of carbohydrates is known to contribute to their biological roles, conformational studies of sugars are challenging because their chains are flexible in solution and consequently the number of 3D structural restraints is limited. Here, we investigate the conformational properties of the tetrasaccharide building block of the Lytechinus variegatus sulfated fucan composed of the following structure [l-Fucp4(SO3-)-α(1-3)-l-Fucp2,4(SO3-)-α(1-3)-l-Fucp2(SO3-)-α(1-3)-l-Fucp2(SO3-)] and the composing monosaccharide unit Fucp, primarily by nuclear magnetic resonance (NMR) experiments performed at very low temperatures and using H2O as the solvent for the sugars rather than using the conventional deuterium oxide. By slowing down the fast chemical exchange rates and forcing the protonation of labile sites, we increased the number of through-space 1H-1H distances that could be measured by NMR spectroscopy. Following this strategy, additional conformational details of the tetrasaccharide and l-Fucp in solution were obtained. Computational molecular dynamics was performed to complement and validate the NMR-based measurements. A model of the NMR-restrained 3D structure is offered for the tetrasaccharide.
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Affiliation(s)
- Francisco F Bezerra
- Institute of Medical Biochemistry Leopoldo de Meis, University Hospital Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21941, RJ, Brazil
| | - William P Vignovich
- BioMolecular Sciences Department, School of Pharmacy, University of Mississippi, University, 38677 MS, USA
| | - AyoOluwa O Aderibigbe
- BioMolecular Sciences Department, School of Pharmacy, University of Mississippi, University, 38677 MS, USA
| | - Hao Liu
- BioMolecular Sciences Department, School of Pharmacy, University of Mississippi, University, 38677 MS, USA
| | - Joshua S Sharp
- BioMolecular Sciences Department, School of Pharmacy, University of Mississippi, University, 38677 MS, USA; Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, 38677 MS, USA
| | - Robert J Doerksen
- BioMolecular Sciences Department, School of Pharmacy, University of Mississippi, University, 38677 MS, USA; Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, 38677 MS, USA
| | - Vitor H Pomin
- Institute of Medical Biochemistry Leopoldo de Meis, University Hospital Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21941, RJ, Brazil; BioMolecular Sciences Department, School of Pharmacy, University of Mississippi, University, 38677 MS, USA; Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, 38677 MS, USA.
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Uslupehlivan M, Şener E, İzzetoğlu S. Computational analysis of the structure, glycosylation and CMP binding of human ST3GAL sialyltransferases. Carbohydr Res 2019; 486:107823. [PMID: 31557542 DOI: 10.1016/j.carres.2019.107823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 09/18/2019] [Accepted: 09/18/2019] [Indexed: 11/24/2022]
Abstract
Sialyltransferases (STs) are the fundamental enzymes which are related to many biological processes such as cell signalling, cellular recognition, cell-cell and host-pathogen interactions and metastasis of cancer. All STs catalyse the terminal sialic acid addition from CMP donor to the glycan units. ST3GAL family is one of the most important STs and divided into the six subfamily in mouse and humans which are ST3Gal I, ST3Gal II, ST3Gal III, ST3Gal IV, ST3Gal V, and ST3Gal VI. The members of the ST3GAL family transfer sialic acid to the terminal galactose residues of glycochains through an α2,3-linkage. There are many reports on the ST3GAL function in mammals but, there is a paucity of information about structure of human ST3GAL family. Herein, we investigated the structure, glycosylation and CMP binding site of human ST3GAL family using computational methods. We found for the first time N-glycosylation positions in ST3Gal IV and VI, mucin type glycosylation in ST3Gal III and O-GlcNAcylation in ST3Gal V and their relation with sialylmotifs. In addition, we predicted CMP binding positions of human ST3GAL enzyme family on three-dimensional structure using molecular docking and first demonstrated the sialylmotifs relation with the CMP binding positions in ST3Gal III-VI subfamilies.
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