Chun-Ting Yuen

Neoglycolipids: probes of oligosaccharide structure, antigenicity, and function.

Publisher Summary Neoglycoproteins have found considerable use in studies of carbohydrate-binding proteins and monoclonal antibodies and are available as commercial products. The special feature of the neoglycolipid technology is that it is applicable not only to mixtures of oligosaccharides released from proteins by established procedures [hydrazinolysis ( N -linked chains) or alkaline borohydride degradation ( O -linked chains) or by various partial degradation procedures, including endoglycosidase digestions] but is also applicable to any desired oligosaccharide sequence, be it natural or synthetic. By a microconjugation procedure each oligosaccharide is joined to a lipid molecule. The resulting neoglycolipids serve as immobilized probes on silica gel chromatograms, on plastic plates, or as microparticulate probes after incorporation into liposomes, and they are readily amenable to assay procedures established for glycosphingolipids. In the form of neoglycolipids, the oligosaccharides are presented at the matrix surface in a clustered state. This is an important requirement for interactions with carbohydrate-binding proteins, including antibodies, which frequently have low affinities and give no detectable binding to monovalent carbohydrate ligands under conventional binding assay conditions. The lipid most extensively used for generating neoglycolipids has been the aminophospholipid L -1,2-dipalmitoyl- sn -glycero-3-phosphoethanolamine.

Recombinant GM2-Activator Protein Stimulates In Vivo Degradation of GA2 in GM2 Gangliosidosis AB Variant Fibroblasts But Exhibits No Detectable Binding of GA2 in an In Vitro Assay*

The interaction between glycosphingolipids and recombinant human GM2-activator was studied in a microwell binding assay. A-series gangliosides like GM3, GM2 and GM1 were strongly bound by the recombinant human GM2 activator. A weak binding was observed to GD1b and sulfatide, while neutral glycolipids were not bound. Optimal binding occurred at pH 4.2 and was inhibited by increasing concentrations of citrate buffer and NaCl. In contrast with these in vitro results the recombinant human GM2-activator is able to restore the degradation of GA2 in fibroblasts from patients with the AB variant of GM2 gangliosidosis in vivo.

Retraction: Oligosaccharide ligands for NKR-P1 protein activate NK cells and cytotoxicity

This corrects the article DOI: 10.1038/372150a0