Nonenzymatic release of free reducing glycans from glycosphingolipids.

A major limitation in studying the structures and functions of glycans in glycosphingolipids is the difficulty in releasing free glycans for analysis and derivatization. Here we show that reducing glycans can be released nonenzymatically from glycosphingolipids after a brief treatment with ozone followed by heating in neutral aqueous buffer (pHs 6.0-8.0). The released free reducing glycans are then available for glycomic analyses, including fluorescent labeling, permethylation, and mass spectrometry. This procedure is simple and highly efficient, with no base-catalyzed "peeling" reaction by-products observed.