Bridging the structural gap of glycoproteomics with ion mobility spectrometry.

Over the past two decades mass spectrometry (MS) has enabled high throughput studies on the level of a complex proteome. While it has similarly advanced glycobiology, the level of progress has been more restrained. This is in large part due to the diversity and complexity of carbohydrate structures. While MS is now routinely used for glycobiology, it suffers from a critical limitation, that is the inability to resolve isobaric structures. Since so many structurally and functionally distinct carbohydrates are indistinguishable by MS, additional techniques are needed for detailed structural analysis. Ion mobility spectrometry (IMS), with its ability to resolve closely related isobaric structures, presents such a tool for alleviating the current limitations of MS. In the past few years studies have demonstrated the utility and immense potential of combining IMS with MS (IM-MS) for glycomics and it is now approaching the point of enabling comprehensive structural studies on the level of the glycoproteome.