George J. Vella

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Many mammalian and avian complex carbohydrates (glycoproteins and glycolipids) have highly branched oligosaccharides. Although the function of complex carbohydrates is not known, there is evidence to suggest that oligosaccharide branching may be an important factor in the process by which cells recognize one another and their environment. Asparagine-linked(More)
Polyacrylamide slab gel electrophoresis has been traditionally used for the analysis of synthetic oligodeoxyribonucleotides. As the demand for oligonucleotides of high purity has increased, a need for additional high resolution analytical techniques has arisen. This report describes the principles and application of capillary gel electrophoresis and(More)
Numerous methods have previously been reported for the final steps in the large-scale purification of plasmid DNA. Although gel permeation and reverse-phase high-performance liquid chromatography have been utilized for this procedure in the past, the limited capacity of these systems often necessitated multiple rounds of chromatography, especially with the(More)
One of the most striking features of N- and O-glycosyl oligosaccharides and of lipid-linked oligosaccharides is the high degree of branching of these complex structures. Both proteins and nucleic acids are essentially linear structures and are synthesized by template mechanisms. The branched nature of complex carbohydrates dictates a totally different(More)
Robotized manufacturing cells are required more and more often to process high variety of short life-cycle product. This increases the need for methods and techniques for easy reconfiguration of software programs running in programmable logic controllers (PLC), i.e., devices able to control manufacturing systems. PLCs run embedded code characterized by a(More)
The synthesis of structural analogs and the process of drug discovery have evolved dramatically through recent advances in solid-phase synthesis reagents and automated screening systems. As molecular diversity strategies emerge, the need for automated target-based selection of lead candidates becomes equally important. Multidimensional automated(More)
Twenty low molecular weight compounds were tested as substrates for UDP-GlcNAc:alpha-D-mannoside (GlcNAc to Man alpha 1-3) beta 2-N-acetylglucosaminyltransferase I (GlcNAc-transferase I) purified from bovine colostrum. This enzyme is at a key control point in the biosynthetic path leading to complex Asn-linked oligosaccharides. The highest activity was(More)
A prototype hydroxylated polymeric support, Glyco-PAK N, was employed to separate a number of neutral reducing oligosaccharides derived from various glycoproteins by the hydrazinolysis/re-N-acetylation/mild acid hydrolysis procedure. General features of the separation properties of the matrix are described. A major advantage of the packing over silica-based(More)
The need for high-purity oligodeoxyribonucleotides for various applications has resulted in the development of novel synthesis, purification, and analytical techniques. A diversity of methods, including polyacrylamide slab gel electrophoresis, capillary gel electrophoresis, as well as high-performance liquid chromatography (HPLC), have been successfully(More)