Understanding the Glycosylation Pathways Involved in the Biosynthesis of the Sulfated Glycan Ligands for Siglecs

ACS Chemical Biology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 21, 2025

Carbohydrate sulfation plays a pivotal role in modulating the strength of Siglec–glycan interactions. Recently, new aspects Siglec binding to sulfated cell surface carbohydrates have been discovered, but class glycan presenting these ligands has not fully elucidated. In this study, contribution different classes glycans cis and trans was investigated within cells expressing carbohydrate sulfotransferase 1 (CHST1) or CHST2. For some Siglecs, mediating clear, such as O-glycans for Siglec-7 N-glycans Siglec-2 Siglec-9. Both mucin-type contributed Siglec-3, -5, -8, -15. However, significant levels Siglec-3 -8 remained CHST1-expressing lacking complex O-glycans. A combination genetic, pharmacological, enzymatic treatment strategies ruled out heparan sulfates glycoRNA contributors, although Siglec-8 did exhibit glycolipids. Genetic disruption O-mannose had small impact on binding, demonstrating that can present ligands. We also ability mask Siglec-7. Siglec-7, were again found be While major largest masking. Overall, study enhances our knowledge types serve

Язык: Английский

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Proximity Labeling and Genetic Screening Reveal that DSG2 is a Counter Receptor of Siglec‐9 and Suppresses Macrophage Phagocytosis

Advanced Science, Год журнала: 2025, Номер unknown

Опубликована: Янв. 15, 2025

Abstract Cancer cells present sialylated glycoconjugates that modulate the activity of various immune within tumor microenvironment through trans interaction with immunosuppressive Siglec receptors. Identifying counter receptors for Siglecs can provide valuable targets cancer immunotherapy, but it presents significant challenges. Here, identification DSG2 (Desmoglein 2) as a dominant receptor Siglec‐9 in melanoma is reported, using workflow combines strength proximity labeling and advantage CRISPR knockout screening. It further demonstrated between mainly dependent on sialic acid‐bearing N ‐glycans DSG2. Importantly, blocking significantly enhances macrophage phagocytosis and, to lesser extent, other cells. The work thus suggests potential “don't eat me” signal molecule therapeutic potentials immunotherapy.

Язык: Английский

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Streamlining Sulfated Oligosaccharide and Glycan Synthesis with Engineered Mutant 6-SulfoGlcNAcases

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Фев. 10, 2025

Sulfation is a common, but poorly understood, post-glycosylational modification (PGM) used to modulate biological function. To deepen our understanding of the roles various sulfated glycoforms and their relevant binding proteins, we must expand enzymatic toolkit for synthesis. Here, bypass need both sulfotransferases glycosyltransferases by engineering series mutants 6-SulfoGlcNAcase, from Streptococcus pneumoniae, directly efficiently synthesize not only ubiquitous 6S-GlcNAc-β-1,3-Gal linkage prevalent within host glycans, also 6S-GlcNAc-β-1,6-GalNAc commonly observed core-6 O-glycans, more exotic 6S-GlcNAc-β-1,4-GalNAc linkage. We further elaborate these into complex N-glycan O-glycan structures relevance. By utilizing cost-effective activated donor pNP-6S-GlcNAc in conjunction with mutant GH185 6-SulfoGlcNAcases demonstrate simple yet powerful vitro method generating well-defined oligosaccharides use variety applications including glycan arrays, remodeling, specificity studies carbohydrate proteins such as lectins.

Язык: Английский

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Ketodeoxynonulosonic Acid Hydroxylase (Kdnase) Assisted Site‐Specific Enzymatic α2,6‐Sialylation

Chinese Journal of Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Март 26, 2025

Comprehensive Summary Owing to its promiscuous substrate specificity and high catalytic efficiency, the bacterial α2,6‐sialyltransferase from Photobacterium damselae (Pd2,6ST) has been widely used for synthesis of various α2,6‐linked sialosides. However, Pd2,6ST is not a suitable enzyme regioselective α2,6‐sialylation complex acceptor substrates containing multiple galactose (Gal) and/or N ‐acetylgalactosamine (GalNAc) residues due specificity. In this study, novel enzymatic engineering strategy was developed overcome limitation by employing enzymatically introduced ketodeoxynonulosonic acid (Kdn) as temporary “protecting group” at unwanted sialylation sites. The Kdn can be selectively removed hydrolase Aspergillus fumigatus ( Af Kdnase) appropriate stage without affecting coexisting sialic residues, such ‐acetylneuraminic (Neu5Ac) or ‐glycolylneuraminic (Neu5Gc). This provides general practical approach sialosides, including sialylated poly‐LacNAc glycans, disialylated ganglioside glycan epitopes, branched human milk oligosaccharides.

Язык: Английский

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One-Step Labeling Strategy for the Profiling of Multiple Types of Protein Glycosylation

Analytical Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Апрель 1, 2025

Protein glycosylation, classified into N-glycosylation and O-glycosylation, is the most prevalent complex protein post-translational modification. Bioorthogonal chemistry reactions combining biotin–streptavidin interaction system are commonly used for investigating glycosylation. In this study, a one-step enzymatic labeling strategy simultaneous global profiling of multiple types glycosylation was developed. A "one-step probe" directly carrying enrichment support poly(N-isopropylacrylamide) (PNIPAM) designed synthesized. Although probe carried large group (the number-average molecular weight PNIPAM up to 10,000 Da), it well accepted by two substrate-specific sialyltransferases label N-glycopeptides O-glycopeptides. temperature-sensitive polymer. When temperature below lower critical solution temperature, water-soluble precipitated when above temperature. The advantage property that labeled glycopeptides were enriched from biological samples simply changing without need additional resins. Following ultraviolet-light-mediated cleavage, N-glycopeptide, core-fucosylated glycopeptide, truncated mucin-type O-glycopeptides (Tn, STn, T, ST antigens) released sequentially via mass spectrometry. This work provides an effective significantly reduce costs types.

Язык: Английский

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Carbohydrate Sulfation as a Critical Modulator of Siglec-Sialoglycan Interactions

Carbohydrate Research, Год журнала: 2025, Номер 553, С. 109502 - 109502

Опубликована: Апрель 25, 2025

Язык: Английский

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Concise synthesis of NDP-activated uronic acid by an oxidation reaction insertion strategy

Chinese Chemical Letters, Год журнала: 2024, Номер unknown, С. 110757 - 110757

Опубликована: Дек. 1, 2024

Язык: Английский

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