In human fibroblasts, the recognition of lysosomal enzymes by cell surface receptors is mediated by mannose 6-phosphate residues located on oligosaccharides that can be cleaved by endo-beta-N-acetylglucosaminidase H. About half of these oligosaccharides, as isolated from beta-hexosaminidase and cathepsin D secreted by human skin fibroblasts, are anionic. Most of these are resistant to alkaline ...

Several lysosomal enzymes currently used for enzyme replacement therapy in patients with lysosomal storage diseases contain very low levels of mannose 6-phosphate, limiting their uptake via mannose 6-phosphate receptors on the surface of the deficient cells. These enzymes are produced at high levels by mammalian cells and depend on endogenous GlcNAc-1-phosphotransferase α/β precursor to phospho...

Specific carbohydrate recognition in biology is a dynamic process. Thus, supramolecular multivalent scaffolds with dynamic features have been applied to mimic this process. Herein, we prepared DNA-dendron supramolecular fibers and synthesized carbohydrate-oligonucleotide conjugates (C18mannose). Via DNA hybridization, the C18-mannose could be guided onto the fiber platform and form multiple man...

A receptor that binds the lysosomal enzyme alpha-mannosidase via mannose 6-phosphate moieties (mannose 6-phosphate receptor) was purified from Swarm-rat chondrosarcoma and bovine liver microsomal membranes. Receptor-reconstituted liposomes were prepared by dialysis of taurodeoxycholate-dispersed lipids with purified mannose 6-phosphate receptor. Liposomes appeared by electron microscopy as 60-1...

Several therapeutic self-proteins elicit immune responses when administered to patients. Such adverse immune responses reduce drug efficacy. To induce an immune response, a protein must interact with different immune cells, including antigen-presenting cells, T cells, and B cells. Each cell type recognizes distinct immunogenic patterns on antigens. Mannose-terminating glycans have been identifi...

The objective of these studies was to characterize the macrophage mannose receptor binding and pharmacological properties of carbohydrate remodeled human placentalderived and recombinant b-glucocerebrosidase (pGCR and rGCR, respectively). These are similar but not identical molecules that were developed as enzyme replacement therapies for Gaucher disease. Both undergo oligosaccharide remodeling...

The effect of brefeldin A (BFA) on the trafficking of the mannose 6-phosphate/insulin-like growth factor II receptor within the endocytic route was analyzed. Treatment with BFA induced a redistribution of the receptor to the cell surface and increased both the binding and internalization of ligands 2-4-fold. The effect of BFA was dose- and time-dependent and reversible. Determinations of transp...

Glycan microarrays prepared by immobilization of amino-functionalized glycans on NHS-activated glass slides have been successfully used to study protein-glycan interactions. Fluorescently tagged glycans with an amino functional group can be prepared from natural glycans released from glycoproteins. These tagged glycans can be enzymatically modified with various glycosyltransferases, phosphotran...

Surfactant protein A (SP-A) binding to bovine alveolar macrophages was examined in order to characterize SP-A binding proteins on the cell surface and to isolate putative receptors from these cells that could be obtained in large amounts. Human SP-A, unlabeled or labeled with gold particles, was bound to freshly isolated macrophages and analyzed with ELISA or the transmission electron microscop...