Megalin (gp 330) is a large cell surface receptor expressed on the apical surfaces of epithelial tissues, that mediates the binding and internalization of a number of structurally and functionally distinct ligands. In this paper we report the first detailed structural characterization of megalin-derived oligosaccharides. Using strategies based on mass spectrometric analysis, we have defined the structures of the N-glycans of megalin. The results reveal that megalin glycoprotein is heterogeneously glycosylated. The major N-glycans identified belong to the following two classes: high mannose structures and complex type structures, with complex structures being more abundant than high mannose structures. The major nonreducing epitopes in the complex-type glycans are: GlcNAc, Galbeta1-4GlcNAc (LacNAc), NeuAcalpha2-6Galbeta1-4GlcNAc (sialylated LacNAc), GalNAcbeta1-4[NeuAcalpha2-3]Galbeta1-4GlcNAc (Sd(a)) and Galalpha1-3Galbeta1-4GlcNAc. Most complex structures are characterized by the presence of (alpha1,6)-core fucosylation and the presence of a bisecting GlcNAc residue.
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http://dx.doi.org/10.1093/glycob/10.3.295 | DOI Listing |
Bioorg Chem
January 2025
Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India; Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India. Electronic address:
Molecular hybridization is an emerging strategy in medicinal chemistry for designing new bioactive molecules that link pharmacophores covalently and shows synergistic enhanced properties. Herein, we have developed pyrazolo[3,4-b]pyridine-based new glycohybrids considering the Warburg effect. A microwave-assisted, copper-catalyzed efficient synthesis of new triazole-linked glycohybrids based on pyrazolo[3,4-b]pyridines scaffold was achieved successfully in high yields with inherent stereochemical diversity from d-glucose, d-galactose, and d-mannose.
View Article and Find Full Text PDFInt J Pharm
January 2025
School of Traditional Chinese Pharmacy, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, PR China. Electronic address:
Compared to conventional nanocarrier-based drug delivery technology, small-molecule-assembled nanomaterials provide various advantages, including higher drug loading efficiency, lower excipient-related toxicity, and a simpler formulation process. Our research constructed a mannonse-modified small-molecule-assembled nanodrug for synergistic photodynamic/chemotherapy against A549 cancer cells. The hydrophobic hypoxic-activated agent tirapazamine (TPZ) and a hydrophilic fluorescence probe Cyanine 3 (Cy3) constitute this amphiphilic prodrug via a glutathione (GSH)-responsive linkage, which could self-assemble into stable nanoparticles (NPs) and encapsulate a newly synthesized photosensitizer (SeBDP).
View Article and Find Full Text PDFProtein Sci
February 2025
York Structural Biology Laboratory, Department of Chemistry, University of York, York, UK.
Tryptophan mannosylation, the covalent addition of an α-ᴅ-mannose sugar to a tryptophan side chain, is a post-translational modification (PTM) that can affect protein stability, folding, and interactions. Compared to other forms of protein glycosylation, it is relatively uncommon but is affected by conformational anomalies and modeling errors similar to those seen in N- and O-glycans in the Protein Data Bank (PDB). In this work, we report methods for detecting, building, and improving mannose structures linked to tryptophans.
View Article and Find Full Text PDFColorectal cancer is the second leading cause of cancer-related deaths worldwide, and its development typically involves complex metabolic reprogramming. By mapping the spatial distributions of metabolites and -glycans in heterogeneous colorectal cancer tissues, we can elucidate cancer-associated metabolic and -glycan changes. Herein, we combine mass spectrometry imaging-based metabolomics and -glycomics to characterize the spatially resolved reprogramming of metabolites and -glycans in colorectal cancer tissues.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Pharmaceutical Science, Dali University, Dali 671000, China; International Joint Laboratory for the Development and Utilization of Traditional Chinese Medicine Resources in Yunnan Province, Baoshan 678300, Dali 671000, China. Electronic address:
Ficus carica (F. carica) is a well-known medicinal and edible plant with high nutritive values. Polysaccharides are the primary and important bioactive components in F.
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