Prediction of Glycan Structures from Glycosyltransferase Expression Profiles

Glycans, which attach to some lipids and Asn/Ser/Thr residues of proteins, draw attentions as the third biological macromolecule next to DNA and protein, since glycans play key roles in the embryogenesis, immunity and diseases. Glycans consist of carbohydrate sugars and their derivatives such as glucose (Glc), mannose (Man), N-acetyl-glucosamine (GlcNAc) and N-acetyl neuraminic acid (Neu5Ac), and form linear and branched structures. Recent advances of NMR and MASS technologies have made it possible to determine more and more structures of glycans, and our laboratory provides a public glycan structural database, KEGG/GLYCAN [2, 4]. Glycans are synthesized by several kinds of glycosyltransferases, each catalyzing formation of a glycosidic-bond between the glycan precursor as an acceptor and the nucleotide sugar as a donor. In this study, we construct a pattern library consisting of bond-formation patterns of glycosyltransferase reactions in human. Using the database and the library, we try to predict the repertoire of possible glycan structures from the expression data of human glycosyltransferase genes. This is a first attempt of glycoinformatics research linking genome to glycome.