Pingying Tang

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The carbohydrate determinants of keratan sulphate recognized by three monoclonal antibodies (5-D-4, 1-B-4 and MZ15) have been investigated by solid-phase radioimmunoassay using bovine corneal keratan sulphate as the immobilized reference antigen. The antibodies appeared highly specific for sulphated poly(N-acetyllactosamine) sequences, for their binding was(More)
Reduced O-linked chains and reducing N-linked chains were obtained from human milk galactosyltransferase by degradation with alkaline borohydride and hydrazinolysis, and then purified by ion-exchange chromatography. The reactivities of the conjugates of the oligosaccharides with L-alpha-phosphatidyl ethanolamine dipalmitoyl (PPEADP) towards monoclonal(More)
Conditions were established for desulphation of hexa-, octa-, deca- and larger oligosaccharides derived from corneal keratan sulphate after treatment with endo-beta-galactosidase. The antigenicities of the desulphated oligosaccharides were compared with those of the native oligosaccharides in chromatogram binding, plastic-plate binding or inhibition of(More)
This report describes the construction of neoglycolipids as a novel approach to determining the antigenicities and receptor functions of minute amounts of oligosaccharides derived from glycoproteins. Reduced oligosaccharides are converted into oligosaccharide alditols by controlled selective periodate oxidation and conjugated to phosphatidyl ethanolamine(More)
In the preceding paper in this journal, the major oligosaccharides obtained by endo-beta-galactosidase digestion of bovine corneal keratan sulphate were identified as a neutral disaccharide, GlcNAc beta 1-3Gal, and sulphated di-, tetra-, hexa-, octa- and decasaccharides based on the sequence (-3/4GlcNAc beta 1-3Gal beta 1-)n having 1, 3, 5, 7 and 9 sulphate(More)
A liquid chromatography-mass spectrometry (LC-MS) method for the analysis of corticosteroids in equine urine was developed. Corticosteroid conjugates were hydrolysed with beta-glucuronidase; free and enzyme-released corticosteroids were then extracted from the samples with ethyl acetate followed by a base wash. The isolated corticosteroids were detected by(More)
A new method for hydrolyzing steroid conjugates (both sulfates and glucuronides conjugates) that is efficient, effective, and inexpensive is described. This method comprises incubation of the conjugates--after salting-out into ethyl acetate or elution from a C18 cartridge--with anhydrous methanolic hydrogen chloride (methanolysis) for 10 min. It has been(More)
A series of oligosaccharides has been isolated from the keratan sulphate peptidoglycan (3 M NaCl fraction) of bovine cornea after digestion with the endo-beta-galactosidase of Bacteroides fragilis. Structural information on the major oligosaccharides was obtained from (a) their susceptibilities to endo-beta-galactosidase before and after desulphation, (b)(More)
A constrained algebraic reconstruction technique (CART) is proposed for the tomographic reconstruction of the ionospheric electron density distribution. The method uses a popular two-dimensional multi-point finite difference approximation of the second order Laplace operator to provide the constraint matrix. The tomographic results of a numerical simulation(More)