E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Synthesis and Biological Applications of Glycoconjugates Ⅱ"

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Bioorganic Chemistry".

Deadline for manuscript submissions: 28 February 2019

Special Issue Editor

Guest Editor
Prof. Dr. Lothar Elling

Laboratory for Biomaterials, Institute of Biotechnology and Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Pauwelsstraße 20, 52074 Aachen, Germany
Website | E-Mail
Interests: glycoconjugates; enzyme cascade reactions; chemo-enzymatic synthesis; glycosyltransferases; nucleotide sugars; galectins; lectins; glycopolymers; biosensors; biomaterials

Special Issue Information

Dear Colleagues,

Glycoconjugates (glycoproteins, glycolipids, proteoglycans) are involved in numerous biological recognition events. Their glycans encode the specific information to trigger protein–glycan interactions. Intercellular crosstalk and pathogen–host interactions are examples and are directly related to the vast chemical diversity of glycan structures. Glycan synthesis via chemical and/or enzymatic approaches are therefore challenging. Novel and efficient procedures for glycan-based products need to be developed and optimized. Multi-enzyme cascade reactions are key for the production of glycans in a larger scale. Protein engineering of enzymes serve to tailor biocatalysts with favorable and novel properties. Most importantly, the combination of chemo- and biocatalysis expands the spectrum of novel synthetic routes. In this way, complex glycans and neo-glycoconjugates will be accessible for biological applications. Multivalency is a key factor for decoding glycan information by carbohydrate recognizing molecules such as lectins and antibodies leading to many applications in biomedicine, biomaterial research, and advanced material sciences. Examples have been seen already in the first Special Issue “Synthesis and Biological Applications of Glycoconjugates” in Molecules in 2017.

I cordially invite you to contribute and share your recent research results in the upcoming second Special Issue on all aspects of the synthesis and biological applications of glycoconjugates.

Prof. Dr. Lothar Elling
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access bimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • glycoproteins
  • glycolipids
  • proteoglycans
  • biocatalysis
  • cascade reactions
  • chemo-enzymatic synthesis
  • lectins
  • biomaterials
  • glycopolymers
  • biosensors
  • glycoconjugates in tissue engineering
  • glycoconjugates of the microbiome
  • glycoconjugates in host-pathogen interaction

Related Special Issue

Published Papers (1 paper)

View options order results:
result details:
Displaying articles 1-1
Export citation of selected articles as:

Research

Open AccessArticle Screening of a Library of Oligosaccharides Targeting Lectin LecB of Pseudomonas Aeruginosa and Synthesis of High Affinity Oligoglycoclusters
Molecules 2018, 23(12), 3073; https://doi.org/10.3390/molecules23123073
Received: 29 October 2018 / Revised: 15 November 2018 / Accepted: 21 November 2018 / Published: 24 November 2018
PDF Full-text (5661 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The Gram negative bacterium Pseudomonas aeruginosa (PA) is an opportunistic bacterium that causes severe and chronic infection of immune-depressed patients. It has the ability to form a biofilm that gives a selective advantage to the bacteria with respect to antibiotherapy and host defenses.
[...] Read more.
The Gram negative bacterium Pseudomonas aeruginosa (PA) is an opportunistic bacterium that causes severe and chronic infection of immune-depressed patients. It has the ability to form a biofilm that gives a selective advantage to the bacteria with respect to antibiotherapy and host defenses. Herein, we have focused on the tetrameric soluble lectin which is involved in bacterium adherence to host cells, biofilm formation, and cytotoxicity. It binds to l-fucose, d-mannose and glycan exposing terminal fucose or mannose. Using a competitive assay on microarray, 156 oligosaccharides and polysaccharides issued from fermentation or from the biomass were screened toward their affinity to LecB. Next, the five best ligands (Lewisa, Lewisb, Lewisx, siayl-Lewisx and 3-fucosyllactose) were derivatized with a propargyl aglycon allowing the synthesis of 25 trivalent, 25 tetravalent and 5 monovalent constructions thanks to copper catalyzed azide alkyne cycloaddition. The 55 clusters were immobilized by DNA Directed immobilization leading to the fabrication of a glycocluster microarray. Their binding to LecB was studied. Multivalency improved the binding to LecB. The binding structure relationship of the clusters is mainly influenced by the carbohydrate residues. Molecular simulations indicated that the simultaneous contact of both binding sites of monomer A and D seems to be energetically possible. Full article
(This article belongs to the Special Issue Synthesis and Biological Applications of Glycoconjugates Ⅱ)
Figures

Graphical abstract

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: β-N-Acetylhexosaminidase in the synthesis of bioactive glycans: protein and reaction engineering
Authors: Pavla Bojarová, Vladimír Křen et al.
Affiliation: Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 14220 Prague, Czech Republic
Emails: ;
Abstract: N-Acetylhexosamine oligosaccharides terminated with GalNAc are attractive synthetic targets since they act as selective ligands of galectin-3, a biomedically important human lectin. β-N-Acetylhexosaminidases (EC 3.2.1.52) used as synthetic tools have the advantage of tolerating a number of functional groups incorporated in both the donor and acceptor carbohydrate molecule. Thus, oligosaccharides carrying desired structural modifications may be prepared [1]. Such modifications at glycan C-1 may be applied for, e.g., covalent attachment of glycans to a multivalent carrier, resulting in glycomimetics with enhanced affnity to galectins [2].
β-N-Acetylhexosaminidases exhibit dual specificity for both N-acetylglucosamine and N-acetylgalactosamine moieties (and thus have both GlcNAcase and GalNAcase activities); this may complicate synthetic applications especially in combination with a side substrate hydrolysis that may occur in the reaction. A point mutation of active-site amino acid Tyr to other amino acid residues, especially Phe, His and Asn, has previously been shown to strongly suppress the hydrolytic activity of β-N-acetylhexosaminidases and substantially increase the synthetic yields [3]. In the present work, we have found that Tyr470 is also an important mutation hotspot for altering the ratio of GlcNAcase/GalNAcase activity, resulting in mutant enzymes with various affinity to GlcNAc/ GalNAc substrates. The enzyme selectivity may also be manipulated by altering the reaction medium upon changing pH or adding selected organic co-solvents. As a result, we are able to fine-tune the β-N-acetylhexosaminidase affinity and selectivity, resulting in a high-yield production of the desired functionalized GalNAcβ4GlcNAc epitope. The present work will show the protein and reaction engineering on a model β-N-acetylhexosaminidase from Talaromyces flavus, recombinantly expressed in Pichia pastoris. The result of the one-step engineered reaction is the production of this carbohydrate epitope in a close-to-quantitative yield, comparable to the synthesis by glycosyltransferases. The impact of this point mutation on the enzyme GlcNAcase/GalNAcase activity will be explained by a detailed molecular modelling and substrate docking study.

References:
1. Bojarová, P., Křen, V. Trends Biotechnol. 2009, 27, 199-209.
2. Bojarová, P., Chytil. P., Mikulová, B., Bumba, L., Konefal, R., Pelantová, H., Krejzová, J., Slámová, K., Petrásková, L., Kotrchová, L., Cvačka, J., Etrych, T., Křen, V., Polym. Chem. 2017, 8, 2647-2658.
3. Slámová, K., Krejzová, J., Marhol, P., Kalachova, L., Kulik, N., Pelantová, H., Cvačka, J., Křen, V. Adv. Synth. Catal. 2015, 357, 1941-1950.

Title: Screening of a library of oligosaccharides targeting Lectin LecB of Pseudomonas aeruginosa and synthesis of oligoglycoclusters of high affinity
Authors: Yann Chevolot and François Morvan
Affiliation: Université de Lyon, Ecole centrale de Lyon, CNRS, Institut des Nanotechnologies de Lyon (INL), UMR CNRS 5270, Site Ecole Centrale de Lyon, Ecully cedex, France
Emails: ;
Abstract: The gram negative bacterium Pseudomonas aeruginosa (PA) is an opportunistic bacterium that causes severe and chronic infection of immune-depressed patient. It has the ability to form a biofilm that gives a selective advantage to the bacteria with respect to antibiotherapy and host defenses. During the formation of the biofilm, several virulent factors are involved. Among these virulence factor, lectins play a key role. Therefore, molecules inhibiting these lectins are envisioned as new anti-bacterial agents. Herein, we have focused on LecB. LecB is a tetrameric soluble lectin involved in bacterium adherence to host cells, biofilm formation, cytotoxicity. It binds to L-fucose, D-mannose and glycan exposing terminal fucose or mannose. Herein, using a competitive assay on microarray, 156 oligosaccharides and polysaccharides issued from fermentation or from the biomass were screened toward their affinity to LecB. Next, the five best ligands (Lewisa, Lewisb, Lewisx, siayl-Lewisx and 3-fucosyllactose) were derivatized with a propargyl aglycon allowing the synthesis of multivalent constructions thanks to copper catalyzed azide alkyne cycloaddition. The binding of the resulting oligoglycoclusters to LecB was determined using a microarray.

Title: Functional Glyco-nanogels for multivalent interaction with lectins
Authors:  Ruben R. Rosencrantz and Alexander Böker
Affiliation: Fraunhofer‐Institut für Angewandte Polymerforschung IAP, Lehrstuhl für Polymermaterialien und Polymertechnologien, Universität Potsdam, Geiselbergstraße 69, 14476 Potsdam, Germany
Emails: [email protected]; [email protected]
Abstract: We synthesize unprotected Di- and Trisaccharide based glycomonomers via microwave assisted reactions to yield glyco-nanogels by precipitation- as well as emulsion-polymerization. The crosslinking density is varied to acchieve unhindered diffusion of lectins throughout the gels. Binding performance of the glyco-gels is evaluated by SPR and ITC with appropriate lectins. Additionally, we prove the biocompatability via cytotoxicity tests.

We assume that the chosen lectins will have high avidity towards the gels and that they will be suitable to acchieve strong interactions as well with toxins or adhesins bearing a lectin-domain. Possible future applications are therfore prevention of toxin or microorganism binding to tissue.

Title: Enzymatic synthesis of tri-deuterated sialosides
Authors: Zhi P. Cai1‡, Louis P. Conway1‡, Ying Y. Huang1‡, Wen J. Wang1‡, Hong L. Yao1 Kun Huang2, Sabine L. Flitsch2, Li Liu1* and Josef Voglmeir1*
Affiliations: 1Glycomics and Glycan Bioengineering Research Center (GGBRC), College of Food Science and Technology, Nanjing Agricultural University, Nanjing, People’s Republic of China; 2Manchester Institute of Biotechnology, University of Manchester, Manchester, United Kingdom; *Correspondence should be addressed to [email protected] (J. V.) or [email protected] (L. L.); Tel: +86-025-8439-9553 Contributed equally.
Email: [email protected]
Abstract: Sialic acids are a family of acidic monosaccharides often found on the termini of cell surface protein or lipid glycoconjugates of the higher animals.  Herein we describe the enzymatic synthesis of the two isotopically labeled sialic acid derivatives d3-X-Gal-α-2,6-Neu5Ac and d3-X-Gal-α-2,6-Neu5Gc. Using deuterium oxide as the reaction solvent, deuterium atoms could be successfully introduced during the enzymatic epimerisation and aldol addition reactions when the sialosides were generated. NMR and mass spectrometric analyses confirmed that more than 95% of the resulting sialosides were trideuterated. These compounds may be of interest as internal standards in liquid chromatography/mass spectrometric assays for biochemical or clinical studies of sialic acids.

text

 

Title: Identification of inhibitor scaffolds by biosensor-based small molecule fragment library screening with Leishmania major UDP-sugar pyrophosphorylase
Authors: Françoise H Routier; Rita Gerardy‐Schahn and Ohm Prakash
Affiliation: Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
Emails: [email protected]; [email protected] and [email protected]
Abstract: Leishmaniasis is a neglected disease caused by different species of the protozoan parasite Leishmania and currently affects 12 million people worldwide. In addition to the substantial morbidity associated with all forms of leishmaniasis, more than 20.000 people die of visceral leishmaniasis annually. The antileishmanial therapeutic arsenal remains very limited in number and efficacy and there is no vaccine for this parasitic disease. One pathway that has been genetically validated as an antileishmanial drug target is the biosynthesis of UDP-glucose (UDP-Glc) and its direct derivative UDP-galactose (UDP-Gal). The de novo biosynthesis of these two nucleotide sugars is controlled by the specific UDP-glucose pyrophosphorylase (UGP). Leishmania parasites additionally express a UDP-sugar pyrophosphorylase (USP) responsible for monosaccharides salvage and able to generate both UDP-Gal and UDP-Glc. Inactivation of these two parasite pyrophosphorylases result in parasite death. The present study reports the identification of structurally diverse scaffolds for the development of USP inhibitors by fragment library screening. Based on this screen, we selected a small set of commercially available compounds and identified molecules inhibiting both Leishmania major USP and UGP with a half maximal inhibitory concentration in the 100 µM range. The inhibitors were predicted to bind at allosteric regulation sites, which were validated by mutagenesis studies. This study sets the stage for the development of potent and Leishmania-specific UGP and USP inhibitors.

Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top