Carbohydrates articles within Nature Chemistry

Featured

  • Article |

    Large collections of defined glycosaminoglycan (GAG) structures have been synthetically challenging to obtain but are required to understand this important class of biomolecules. Now, an efficient platform for synthesizing large libraries of heparan sulfate oligosaccharides has been developed, providing a detailed view into the sulfation code of GAGs.

    • Lei Wang
    • , Alexander W. Sorum
    •  & Linda C. Hsieh-Wilson
  • Article |

    The inability to access well-defined polysaccharides in sufficient quantities has hampered our understanding of their structure–function relationships. Now it has been shown that native precision polysaccharides can be readily prepared via living polymerization of 1,6-anhydrosugars. The obtained polymers display excellent chemical recyclability, suggesting their potential utility as a class of sustainable materials.

    • Lianqian Wu
    • , Zefeng Zhou
    •  & Jia Niu
  • Article |

    Protein–carbohydrate interactions remain challenging to study due to their low binding affinity and non-covalent nature. Now, a genetically encoded bioreactive unnatural amino acid containing sulfonyl fluoride has been shown to crosslink a protein with its bound glycan, offering a solution to probe and exploit protein–carbohydrate interactions.

    • Shanshan Li
    • , Nanxi Wang
    •  & Lei Wang
  • In Your Element |

    Christine M. Le takes a look at 2-[18F]fluoro-2-deoxyglucose and explains how this radioactive sugar could help to save your life.

    • Christine M. Le
  • Article |

    The specificity of human and animal viruses that engage with O-acetylated sialic acids has now been probed using a collection of O-acetylated sialoglycans obtained by diversification of trisaccharide precursors with viral haemagglutinin–esterases. The results revealed host-specific patterns of receptor recognition and showed that human respiratory viruses uniquely employ 9-O-acetylated α2,8-linked disialosides as receptors.

    • Zeshi Li
    • , Yifei Lang
    •  & Geert-Jan Boons
  • Review Article |

    Metabolic labelling with unnatural sugars can be used to selectively label tumours with chemical tags. These tags then enable the targeted delivery of molecular cargo including diagnostic and therapeutic agents. This Review Article discusses progress in the design and delivery of unnatural sugars for metabolic labelling of tumour cells and the subsequent development of tumour-targeted chemistry.

    • Hua Wang
    •  & David J. Mooney
  • Article |

    An automated platform that can synthesize a wide range of complex glycans could greatly facilitate progress in glycoscience. Now, a fully automated process for enzyme-mediated oligosaccharide synthesis has been developed. This process uses glycosyltransferase-catalysed reactions performed in solution, with product purification being accomplished by solid phase extraction using a sulfonate tag.

    • Tiehai Li
    • , Lin Liu
    •  & Geert-Jan Boons
  • Article |

    Synthetic receptors can be used to help understand biological systems, but rarely compete in terms of affinity or selectivity. Now, a glucose-binding compound has been prepared that, despite its symmetry and simplicity, can match all but the strongest glucose-binding proteins. The high binding affinity and outstanding selectivity of this receptor may translate into biomedical applications.

    • Robert A. Tromans
    • , Tom S. Carter
    •  & Anthony P. Davis
  • News & Views |

    As the most abundant class of biomolecules on Earth, carbohydrates are implicated in a multitude of biological functions. Now, a simple chemical transformation has enabled the direct and selective installation of carbohydrates onto a diverse range of small molecules and peptides.

    • Lara R. Malins
  • Article |

    Capsular polysaccharides are a protective layer enveloping pathogenic bacteria. Understanding their export could guide the design of therapeutics that render bacteria vulnerable to attack by the immune system or other therapeutic agents. Now, a synthetic strategy of polyglycosylation has been developed to obtain defined capsular polysaccharide fragments. Subsequent nanolitre detection enables their export to be studied at the single-molecule level.

    • Lingbing Kong
    • , Andrew Almond
    •  & Benjamin G. Davis
  • Article |

    The glycoprotein gp120 is found on the surface of the HIV viron; it is essential for virus entry into cells. Now, an efficient modular synthesis of N-glycans and the preparation of a mixed-glycan array on aluminium-oxide-coated glass slide is described. This is a vital step in understanding the complex compositions of gp120 and thus important for the development of new HIV therapies.

    • Sachin S. Shivatare
    • , Shih-Huang Chang
    •  & Chi-Huey Wong
  • News & Views |

    Vaccination with a synthetic glycoconjugate, in combination with the administration of an inhibitor that blocks capsular polysaccharide synthesis in bacteria, could offer an alternative route to combat bacterial infections.

    • David Bundle
  • Article |

    The presence and linkage of unusual higher sugars in the ‘inner core’ of Gram-negative bacteria makes the core lipopolysacchride tetrasaccharide Hep2Kdo2 a tough target. Now, a 2+2 glycosylation strategy has facilitated the synthesis of this glycoconjugate. Synthesis of Hep2Kdo2 enabled an antibacterial vaccination strategy based on immunization with the glycoconjugate and the subsequent administration of an inhibitor that uncovers the corresponding epitope in pathogenic bacteria.

    • Lingbing Kong
    • , Balakumar Vijayakrishnan
    •  & Benjamin G. Davis
  • Article |

    O-linked N-acetyl-glucosamine (O-GlcNAc) has been identified as an endogenous modification of α-synuclein; however, its effect on the properties of the protein is unclear. Now, recombinant protein and synthetic peptides have been combined to produce both unmodified and site-specifically O-GlcNAc-modified α-synuclein. The O-GlcNAc modification at threonine 72 was shown to inhibit the aggregation and associated toxicity of α-synuclein.

    • Nicholas P. Marotta
    • , Yu Hsuan Lin
    •  & Matthew R. Pratt
  • Article |

    Designing synthetic molecular receptors that can differentiate between specific monosaccharide guests is very challenging. Now, a helically folded oligoamide that selectively encapsulates fructose has been designed using an iterative approach that exploits the modular structure of folded synthetic oligomer sequences, in conjunction with molecular modelling and structural characterization.

    • Nagula Chandramouli
    • , Yann Ferrand
    •  & Ivan Huc
  • Article |

    Identification of glycosylation patterns is complicated by the lack of sensitive analytical techniques that can distinguish between epimeric carbohydrates. It has now been shown that ion-mobility tandem mass spectrometry of ions derived from glycopeptides and oligosaccharides enables glycan stereochemistry to be determined, highlighting the potential of this technique for sequencing complex carbohydrates on cell surfaces.

    • P. Both
    • , A. P. Green
    •  & C. E. Eyers
  • News & Views |

    Synthetic receptors with properties resembling those of carbohydrate-binding proteins are known, but they are structurally rather complex. Elaborate structures are, however, not always required to bind carbohydrates in water — much simpler compounds can be just as effective.

    • Stefan Kubik
  • Article |

    Oligosaccharides displayed at cell surfaces have important biological functions — such as controlling the entry of viruses — but a full understanding of this behaviour requires the synthesis of such compounds, which remains challenging. Here, two synthetic octasaccharides were shown to have remarkably similar inhibition of herpes simplex virus type 1 infection of cell cultures to the natural oligosaccharide identified in enzymatic studies.

    • Yu-Peng Hu
    • , Shu-Yi Lin
    •  & Shang-Cheng Hung
  • News & Views |

    An enzyme that is unusually tolerant of a truly broad range of substrates can catalyse aldol-type chemistry on sugars in which the various hydroxyl groups are protected. The new methodology combines some of the most important advantages of enzyme and small-molecule catalysis.

    • Benjamin G. Davis
  • Article |

    Ready access to sugars in which the various hydroxyl groups are differentially protected will be of benefit in the production of vaccines, antibiotics and drugs. Here, a chemoenzymatic method that provides a direct route to such protected sugars is described.

    • Dennis G. Gillingham
    • , Pierre Stallforth
    •  & Donald Hilvert