Unexpected structure of a C. difficile toxin A ligand necessitates an annotation correction in a popular screening library

Department of Chemistry, Alberta Ingenuity Centre for Carbohydrate Science, University of Calgary, Calgary AB T2N1N4, Canada.
Chemical Communications (Impact Factor: 6.83). 12/2011; 47(45):12397-9. DOI: 10.1039/c1cc15344g
Source: PubMed


The structure of the pentasaccharide S259-1 in the Consortium for Functional Glycomics was investigated using a variety of techniques. Surprisingly, the structure differs from the structure assumed from the previously established specificity of the human fucosyltransferase FUT-III used in the last step of chemoenzymatic synthesis. When presented with a tetrasaccharide substrate containing both type I and type II disaccharide moieties, the enzyme generates a pentasaccharide in which the type II moiety is preferentially fucosylated. The unexpected product generated by FUT-III in this case highlights the importance of performing detailed structural analysis on products generated by enzymes.

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