Ultrasensitive profiling and sequencing of N-linked oligosaccharides using standard DNA-sequencing equipment.

The analysis of protein-linked glycans is of increasing importance, both in basic glycobiological research and during the production process of glycoprotein pharmaceuticals. In many cases, the amount of glycoprotein available for typing the glycans is very low. This, combined with the high branching complexity typical for this class of compounds, makes glycan typing a challenging task. We present here methodology allowing the medium-throughput analysis of N-glycans derived from low picomole amounts of glycoproteins using the standard DNA-sequencing equipment available in any life sciences laboratory. The high sensitivity of the overall analytical process (from glycoprotein to results) is obtained using state-of-the-art deglycosylation procedures combined with a highly efficient and reproducible novel postderivatization cleanup step involving Sephadex G10 packed 96-well filterplates. All sample preparation steps (enzymatic deglycosylation with PNGase F, desalting, derivatization with 8-amino-1,3,6-pyrenetrisulfonic acid, and postderivatization cleanup) are performed using 96-well-based plates. This integrated sample preparation scheme is also compatible with capillary electrophoresis and MALDI-TOF-MS platforms already in use in some glycobiology labs and anticipates the higher throughput that will be offered by the capillary-array-based DNA sequencers currently penetrating the market. The described technology should bring high-performance glycosylation analysis within reach of each life sciences lab and thus help expedite the pace of discovery in the field of glycobiology.