Aldonate coupling, a simple procedure for the preparation of carbohydrate-protein conjugates for studies of carbohydrate-binding proteins

Aldonate coupling a new, high-yield method for conjugation of reducing oligosaccharides to proteins is described. It involves oxidation of the oligosaccharides to their corresponding aldonic acids followed by coupling to amino functions of proteins by activation of carboxyl groups with a water-soluble carbodiimide derivative. The immunochemical properties of some of these synthetic glycoproteins were assessed using several plant agglutinins (lectins) as well as antibodies raised to the conjugates. The scope and limitation of the method are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21712/1/0000104.pd

Breather lattice and its stabilization for the modified Korteweg-de Vries equation

We obtain an exact solution for the breather lattice solution of the modified Korteweg-de Vries (MKdV) equation. Numerical simulation of the breather lattice demonstrates its instability due to the breather-breather interaction. However, such multi-breather structures can be stabilized through the concurrent application of ac driving and viscous damping terms.Comment: 6 pages, 3 figures, Phys. Rev. E (in press

Interaction of pneumococcal S-14 polysaccharide with lectins from Ricinus communis, Triticum vulgaris, and bandeiraea simplicifolia

Two purified lectins, namely, wheat-germ agglutinin (from Triticum vulgaris) and the hemagglutinin from Ricinus communis seeds, readily form a precipitate with pneumococcal S-14 polysaccharide, whereas the Bandeiraea simplicifolia lectin (BS 1) does not. Exhaustive periodate oxidation and borohydride reduction of S 14 modifies terminal [beta]--galactopyranosyl residues, as well as chain -glucopyranosyl residues, and abolishes reactivity with both the R. communis lectin and wheat-germ agglutinin. Controlled periodate oxidation followed by Smith degradation cleaves only terminal [beta]--galactopyranosyl residues, giving a linear polymer, the structure of which was determined by methylation analysis. This derived polymer, containing (1-->6)-linked 2-acetamido-2-deoxy-[beta]--glucosyl residues, readily precipitated wheat-germ agglutinin, but not the R. communis lectin.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22848/1/0000409.pd

Carbohydrate binding studies on the lectin from Datura stramonium seeds

The carbohydrate-binding properties of the Datura stramonium seed lectin were studied by equilibrium dialysis, quantitative precipitation of natural and synthetic glycoproteins, and hapten inhibition of precipitation. The dimeric lectin (Mr = 86,000) possesses two carbohydrate-binding sites for N,N',N'',N[triple prime]-tetraacetylchitotetritol/mol protein, with an apparent Ka = 8.7 x 103M-1 at 4 [deg]C. Whereas fetuin and orosomucoid reacted poorly with the Datura lectin, the asialo derivatives of these glycoproteins gave strong precipitation with the lectin. Carcinoembryonic antigen, type 14 pneumococcal capsular polysaccharide, and bovine serum albumin, highly substituted with N,N'- diacetylchitobiose units, also precipitated the lectin. Of the homologous series of chitin oligosaccharides tested, N,N',N[triple prime]-triacetylchitotriose was over 6-fold more potent than the disaccharide (N',N'-diacetylchitobiose) which, in turn, was 90 times more reactive than N-acetyl--glucosamine.N-Acetyllactosamine [[beta]--Gal-(1 --> 4)--GlcNAc] was also a potent inhibitor of Datura lectin being equivalent to N,N'-diacetylchitobiose. The requirement for an N-acetyl--glucosaminyl unit linked at the C-4 position was established. The biantennary pentasaccharide (penta-2,6) was a 500-fold more potent inhibitor than N-acetyllactosamine, suggesting that it might interact with both saccharide-binding sites of the Datura lectin simultaneously.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24798/1/0000224.pd

A new class of model glycolipids: Synthesis, characterization, and interaction with lectins

A method is described for preparing model glycolipids by linking aldobionic acids to an alkylamine through an amide bond. These compounds may be rapidly prepared in large quantities. The glycolipids precipitate specifically with lectins. Precipitation occurs at glycolipid concentrations just above their critical micelle concentration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23555/1/0000515.pd