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R A Rastall

Publications and source records attributed to R A Rastall.

22 records · Page 2Linked to original sources
PubMed1995

Gluco-oligosaccharide production by a strain of Erwinia amylovora.

When grown in sorbitol-asparagine-salts medium, cells of Erwinia amylovora isolate T83 released a mixture of oligosaccharides and lipopolysaccharide in place of extracellular polysaccharide. The oligosaccharide fraction was usually readily separable from lipopolysaccharide by gel permeation chromatography, but some samples required disaggregation by preliminary treatment with EDTA. By 1H- and 13C-NMR spectroscopy, methylation analysis and mass spectrometry, the oligosaccharide fraction was shown to consist of terminal, beta-1,2- and beta-1,2,6-linked D-glucose residues in the ratio 2.2:2.6:1, indicating a branched oligosaccharide structure. The purified oligosaccharide fraction was partially resolved by gel permeation chromatography into two components containing approximately equal amounts of glucose. When grown on pear slices, isolate T83 produced normal extracellular polysaccharide.

Erwinia↗
PubMed1993

Primary sequence analysis and representation techniques in carbohydrates.

Sequence similarity calculations of carbohydrates present several problems which must be addressed if a computer implementation is to be achieved. These problems range from the computational representation of the complex carbohydrate structure to the method by which the comparison of residue and linkage is to be made. This paper therefore discusses the form of this representation and how two or more carbohydrates can be meaningful compared. An example set of results using this approach is presented and discussed to illustrate how similarity comparison can show relationships between carbohydrates, features that are otherwise hidden by the sheer volume of data which must be considered.

Algorithms↗
PubMed1992

The application of aqueous two-phase systems to oligosaccharide synthesis by alpha-mannosidase catalysed glycosyl transfer reactions.

Aqueous two-phase systems formed from PEG and dextran have been applied to the synthesis of oligosaccharide by Jack bean alpha-mannosidase in reverse. Whilst rates of synthesis and percentage yields were similar in two-phase systems and one-phase aqueous buffer systems, a ten-fold increase in yield of product per unit of enzyme was seen. In addition, the use of aqueous two-phase systems offers potential process advantages over one-phase systems for the synthesis of oligosaccharides.

Carbohydrate Sequence↗