Nat. Methods 13, 528–534 (2016)

Glycans are a diverse class of carbohydrate–biomolecule conjugates that have many different biological functions. Yet, because of their complex and heterogeneous structures, glycoconjugates have been less tractable to chemical synthesis and analytical characterization than other biomolecules, a fact that has hindered mechanistic glycobiology. Song et al. now report an approach called ORNG (oxidative release of natural glycans), which enables scalable glycomic profiling of biological samples. ORNG uses sodium hypochlorite (NaClO), the reactive component of household bleach, to release glycans from protein and lipid glycoconjugates into products that can then be tagged with visualization reagents, analyzed by HPLC and MS, or used to construct glycan microarrays. In the case of N-glycans from sources including eggs and human saliva, NaClO treatment oxidatively cleaves the asparagine glycosidic bond to produce glycans with free reducing ends. ORNG can also identify sites of protein O-glycosylation, by releasing glycans terminated with O-linked glycolic or lactic acid moieties, and was used to profile O-glycans from mouse gastrointestinal tissues. ORNG was also effective in fragmenting glycosphingolipids from porcine brain tissue to produce cyanomethyl glycosides, which could be further derivatized by selective chemistries. Taken together, ORNG offers a straightforward and preparative method for future analyses of the biological roles of glycoconjugates.